CN101882751A - Nanometer laser - Google Patents

Abstract

The invention provides a nanometer laser application technology and materials for preparing nanometer laser, etc. A crystal-based prepared laser is replaced by an ordered materia-based prepared laser, so the nanometer laser can also be applicable to all fields and ranges of the existing laser, such as spatial nanometer laser communication, nanometer laser stereo rapid prototyping, nanometer laser biological manufacture, nanometer laser rapid prototyping, nanometer laser wireless communication, nanometer laser display, lightening control and fog dispersal by nanometer laser, nanometer laser range finding, nanometer laser radars, nanometer laser guidance and navigation, nanometer laser processing, nanometer laser fusion, nanometer laser photoelectronic warfare and the like. Moreover, the nanometer laser can give a full play in the aspects of military, medicine, energy, traffic, information, communication, materials and the like. The nanometer laser serving as an information transfer tool has favorable application prospect in the aspects of photo-communication, optical information processing and storing, robot vision and the like.

Description

Nanometer laser

Technical field the present invention relates to nanometer technology (Nano technology), laser technology (Laser technology), optical technology (Lighttechnology), electroporation (Electronic technology) and semiconductor technology (Semiconductor technology) etc.

The structure of material and characteristics of motion etc. can be explored and understand to the character of nanometer laser own, and nanometer laser will play an important role in basic scientific research.

The medium that nanometer laser transmits as information will obtain extensive use in optical communication, optical information processing and fields such as storage, robot vision.

Nanometer laser, changes the attribute of material or material is carried out processed etc. the effect that is applied to material as a kind of form of energy.

Nanometer laser will have excellent performance and cost performance in various aspects such as illumination, color, photograph, film, TV, CD, beauty treatment and diagnosis and treatment.

Background technology laser is that (light amplification by stimulated emission ofradiation, Shrink Laser.) writes " the stimulated emission light amplification of radiation ".The zone of radiation laser is commonly referred to active area.Two necessary conditions that laser generates: produce enough population inversion in the active area; Have the optical resonance parts, and in active area, set up stable concussion.It has four big features: the high monochromaticity of the high brightness of light, the high directivity of light, light and the high coherence of light.Not mutually independently between these characteristics, but associated mutually.

Laser generally is made up of three parts, i.e. working-laser material, pumping source and optical resonator.In solid state laser, mostly adopt the optical excitation mode.The atom that is laser absorbs the energy of incident photon and transits to upper state, sends laser when it returns lower state.

If be in high level E ₂On electron density N ₂Greater than being in low-lying level E ₁On electron density N ₁The time, the stimulated radiation process is occupied an leading position, and the intensity that light wave moves in medium increases by index law, and light is exaggerated; This medium is corresponding to laser amplifier.If N ₂Less than N ₁The time, the photonic absorption process is occupied an leading position, and during light wave process medium, intensity is pressed the index law decay, and light is absorbed.

Material grainses such as each molecule or atom have definite energy, are called an energy level of this particle.Certain particle is in the minimum microstate of energy, is called ground state E ₀Be in the higher microstate of energy, be called excitation state E ₂Or E ₃Deng.Wherein long excitation state is metastable state the life-span.

In solid state laser, the active ions Inlaid that plays the stimulated radiation effect be embedded in crystal or noncrystal (as employing glass) and so on solid matrix in, the density of its active ions is more much bigger than the particle density of gas operation material.As the crystal of matrix or noncrystally make bar-shapedly usually, both ends of the surface are polished to optical flat, and have the good depth of parallelism.Plate reflectance coating in both ends of the surface and constitute optical resonator, also can adopt two other speculums to constitute resonant cavity.Solid state laser generally adopts the optical pumping pumping, and pumping source can be continuously luminous or pulsed is luminous; Light source is xenon lamp or high-pressure mercury-vapor lamp normally.Diode pumping (DPSS) has very high pump power and reliability.

Semiconductor laser (Semiconductor Laser) adopts the compound of gallium (Ga), arsenic (As), indium (In), phosphorus (P) and aluminium materials such as (Al) to make usually.Laser diode (Laser Diode, LD); Three kinds of structures that can be divided into homojunction, heterojunction and quantum well.Non equilibrium carrier (electronics or hole) is injected semiconductor PN, can realize injection laser.Realize that it is the necessary condition of junction semiconductor laser that the charge carrier counter-rotating distributes; In order to obtain the necessary and sufficient condition of strong coherent laser radiation; Semiconductor laser also needs optical resonator.

Laser diode (LD) normally is made of the limiting layer on epitaxially grown active layer and active layer both sides, and resonant cavity is made of two cleavage surfaces of crystal usually.When applying forward bias voltage, the existence of the potential barrier of heterogenous junction that produces owing to Bands crack difference can not be spread the electronics that is injected in the active layer and hole and in the active layer that is limited in approaching, can be realized population inversion easily.Even have only very little electric current to pass through, electronics and hole concentration in the micron-sized active layer (0.1-0.2 micron) are also higher, just can obtain bigger gain with very little electric current.The refractive index of the refractive index ratio limiting layer of narrow band gap active layer is big simultaneously, and light wave is to the big regional centralized of refractive index, so light wave also is limited in the active layer.

The full-solid state high power continuous wave green (light) laser of diode-end-pumped is replacing huge, the inefficient argon ion laser of structure at present.

1 nanometer equals 10 ^-9Rice; It is one of long measure.Size is called nanoparticle between the structure of matter particle of 0.1-100 nanometer, is called for short to receive grain; It is about 1 times-1000 times of atomic radius, is a kind of typical Jie's sight system.Nanometer relates to the Science and Technology of atom and molecular level.

The wavelength of particle size and electronics received of particle is the same order of magnitude, and electronics is limited in a very little space, and transmission obviously can be restricted.

(Scanning tunneling microscope STM) is used for detecting microscopic appearance to scanning tunnel microscope.It has high spatial resolving power, and promptly the resolution of parallel direction is 0.04 nanometer, and the resolution of vertical direction is 0.01 nanometer.The principle of STM is a quantum tunneling effect.Its main composition has: top diameter be about the 50-100 nanometer superfine probe (the normally needle point of tungsten system), be used for three orthogonal piezoelectric ceramic (P of 3-D scanning _X, P _Y, P _Z) and be used to scan and the controller (Fig. 1) such as (Controller) of current feedback.

STM has two kinds of mode of operations: constant current mode and permanent height pattern.It is the machining tool of microcosmos, can be on demand, and the atom of manually arranging.Utilize the needle point (being pin end atom) of STM that the attraction of sample atoms or molecule is handled and mobile atom or molecule, they are arranged again.

Summary of the invention task of the present invention is essence, proposition nanometer laser application technology and the preparation nanometer laser material etc. that disclose nano-substance.It relates to each branch field of nanometer laser technology, has contained various aspects such as physics, chemistry, biology, the energy, material, information, control, computer, network, electromechanics, Aero-Space, automobile, microelectronics, measurement, medicine, light industry, military affairs, manufacturing.Nanometer laser will brought into play important effect as a kind of form of light energy to attribute that changes material or the application of material being carried out each side such as processed; The character of nanometer laser can be used to explore and understands the structure of material and characteristics of motion etc.The nanometer laser technology will be immeasurable to the contribution of human material progress and cultural and ideological progress.

By receiving that grain constitutes the space lattice structure and in three dimensions, having at least adjacent on the one dimension large scale lines to receive distance material in the nanoscale scope all between the grain, be called nano-substance.This definition has essential distinction with existing " nano material ".These lines are straightway or curved section.

Have only the distance nano-substance in the nanoscale scope all between the adjacent sodium grain on the one dimension large scale line, be called quantum wire (or nano wire).

Have only the distance nano-substance in the nanoscale scope all between the adjacent sodium grain on the two-dimentional large scale face of linear independence, be called quantum face (or nano thin-film).This face can be planar section or curved sections.

Distance between the adjacent sodium grain in three-dimensional large scale space is the nano-substance in the nanoscale scope all, is called quantosome (or nano block).

Diameter is between the 0.1-100 nanometer and have the particle of communization electronics, is called quantum dot.The aggregation of countless quantum dots is called nano powder.

Have each the adjacent intergranular distance of receiving on the large scale direction in the nano-substance at least, with the electronics de Broglie wavelength quite or littler; Receive then that periodic boundary condition is changed between the point (or receive grain), must cause its optical property, electric property and other various performance generation basic changes.This quantum effect is the essential distinction of nano-substance and common objects.Nano-substance is compared with common material, be not the quantitative change of distance between the simple particle, but qualitative change has taken place the feature of object.When object becomes nano-substance, present many unusual physics and chemical characteristic.These characteristics derive from small-size effect, skin effect and quantum effect.The a lot of peculiar character of nano-substance are the coefficient results of these several effects.

Receive the grain each appearance plane, be called the face of receiving.Two angles of receiving between the face are called Na Mianjiao.Receive the straight line that face intersects for two, be called and receive rib.

It is orderly that the receiving between the grain of nano-substance inside arranged; On its profile, show certain systematicness.An appearance of receiving is surrounded by regular planar; It receives face exactly.Because the difference of formation condition, with a kind of nano-substance, it is not necessarily identical that it receives the rule of face.Receiving the influence of the size of face and shape external condition when generated by nano-substance, is not the characteristic factor of nano-substance.Nano-substance is subjected to inside quality or structures shape and the factor that not influenced by external condition is to receive angle between the face.Each nano-substance all has a cover to be different from the characteristic angle of other nano-substances.

Receive the lasw of constant angle: belong to the nano-substance of same kind, each is received the correspondence of grain and receives the face angle and equate.This is a general rule.

Receive the position of centre of gravity of grain, be called the node of nanometer space topological structure.Each of nano-substance receive the grain center of gravity or its identical point, be called and receive a little.

All receive a little overall in the nano-substance, are called the space lattice of this material.By receiving a little in these space lattices, can do being parallel to of many different directions receive rib family of straight lines and be parallel to the family of planes of the face of receiving.The space lattice of nano-substance structure with many space lattices that family of straight lines is connected and forms, is called Na Ge.The lattice essence of receiving is little space lattice; Has tangible geometry.

Any space topological structure of nano-substance, can by receive o'clock along 3 linear independences receive the rib direction, respectively by certain distance periodically translation constitute.The distance of translation each time is called the rib cycle of receiving on this direction.The rib cycle of receiving on the different directions generally is inequality.

Any three-dimensional is received lattice can both be with certain suitable parallelepiped as elementary cell, and 3 irrelevant one-dimensional spaces of property along the line are periodically piled up and obtained.The geometric units that this periodicity repeats is called receives unit.Receiving in the nano-substance that unit chooses is arbitrarily; Be of practical significance and select method to have two kinds:

A kind of is the unit that receives that has the repetition of minimum period property in the nano-substance, is called primitive unit cell.Be that its atom, ion, molecule or bunch grain of comprising is minimum.

Another kind is can reflect to greatest extent to receive the minimum unit of lattice symmetric property, is called to receive born of the same parents.The physical length on its each limit is called receives the lattice constant.The born of the same parents' essence of receiving is can reflect fully and receive the minimum geometric units of lattice feature from receiving of choosing the lattice.The born of the same parents that receive represent with the length and the angle of its seamed edge.

The Na Ge that only comprises an atom in the primitive unit cell is called skeleton symbol and receives lattice; The Na Ge that comprises an above atom (or ion) is called the compound lattice of receiving.

Internal structure is the nano-substance of rule fully, is called the complete material (or ideal receive material) of receiving.In fact nano-substance exists scrambling more or less, has formed the unordered composition of the minute quantity in the long-range order.The trace of nano-substance inside receive the grain depart from regularly arranged imperfection zone, be called the nano-substance defective.The nano-substance defective is considerably less, accounts for 1/1000. at most and adopts some specific process can produce the complete material of receiving that contains defective hardly.According to geometric properties, the defective of nano-substance is divided into " point " defective, " line " defective and " face " defective.It is very big to the performance impact of nano-substance.The external impurity that advances disastrously is exactly a kind of defective; Silicon nano-substance Be Controlled is mixed suitable trace carbon element, just becomes excellent semiconductor.

" point " defective: the size of three linear independence directions all is nano level, is equivalent to the yardstick of atom; As room, gap or displaced atom.

" line " defective: the size of two linear independence directions all is nano level, and the size of another linear independence direction is relatively very big; As dislocation.

" face " defective: the size of a direction is nano level, and the size of two other linear independence direction is relatively very big; Ru Najie, Ya Na circle.

The grain of receiving is single atom, ion, molecule or the particulate be made up of them.The solid nano material is divided into (order) and unordered (non-order) in order.

Elementary cell when the grain of receiving contains several atoms and ionic structure is called primitive.This topoligical node of receiving grain both can have been represented the center of gravity of primitive, also can represent any identical point in each primitive.If the grain of receiving is made up of identical a kind of atom, node is this atom (or primitive) center of gravity.

The grain of receiving is made the nano-substance that regular periodicity long-range order is arranged in the small scale scope, is called the nano-substance that foreword is arranged, and abbreviates the preface material as.

The spatial arrangements of grain received not have the periodicity or the nano-substance of random combination, is called the nano-substance of lack of alignment, is called for short non-preface material.

The preface material is a long-range order, has translational symmetry; Non-preface material is that translational symmetry is broken scarce, loses long-range order.This is that they are distinguished substantially.

It is small that nano-substance is not simple object particle size, key be have at least on the one dimension large scale in order or each of lack of alignment receive grain adjacent between distance belong to nanometer scale.This is the essence that nano-substance has specific function." nano-substance " implication represents that it compares with other materials, has significantly different good physics or chemical property.It contains the application of various aspects such as physics, chemistry, electromechanics, biology, machinery, automobile, the energy, material, measurement, semiconductor, nanoelectronic, control, computer, information, network, medicine, weaving, military affairs, manufacturing and Aero-Space.

Any one receives arest neighbors, equidistant number of receiving of grain in the identical object of structure, is called the object ligancy.It is less than or equal to 12.

The born of the same parents that receive in the identical object of structure comprise receive the shared volume of grain with receive the long-pending ratio of cell space, be called the object density.It is less than or equal to 0.74.

Each receives grain large scale direction in whole material space dot matrix is the nano-substance that long-range order is arranged, and is called the pure material of receiving in order, is called for short the preface material.

By the nano-substance that many small scale space preface material of irregularly arranging are formed, be called and mix the preface material.Wherein fritter preface material also abbreviates the preface material as.

The grain of receiving is meant the particle of particle diameter less than 100 nanometers; Greater than 100 nano particles, be called powder; Less than 2 nano particles, be also referred to as cluster.

Receive intragranular portion, also can have the orderly order (or crystalline state) of arranging of anisotropy or the non-order (or amorphous state) of isotropism lack of alignment.

The order of preface material shows 3 aspects: each three-dimensional is received lattice corresponding and is received rib with to receive the angle identical in the topological structure of preface material; Each receives the neighbour of grain, and to receive a number (object ligancy) identical; Each receives the geometric position (spacing between the particulate, azimuth etc.) that grain arranges is orderly.

The fundamental difference of crystal and preface material is: exist the various cracks or the defective of micron number magnitude yardstick in the crystal structure, and these cracks or defective make do not exist in the crystal basic structural unit (primitive) on each large scale direction that it has adjacent between distance all less than 100 nanometers.

The fundamental difference of polycrystal and mixed preface material is: have the various cracks or the defective of micron number magnitude yardstick in the polycrystal structure, and these cracks or defective make and do not exist in this polycrystal primitive on each large scale direction that it the has distance between adjacent all less than 100 nanometers.

The difference of noncrystal and non-preface material is: have the various cracks or the defective of micron number magnitude yardstick in the non-crystal structure, and these cracks or defective make this do not exist in noncrystal the basic structural unit (primitive) of each large scale direction that it has adjacent between distance all less than 100 nanometers.

Crystal is not neomorph-" elicit illness state " of the structure of matter of mystery.Its different in kind is because its structure in the preface material; It is a kind of ordinary matter.

By N type that is no less than a kind of semiconductor preface material different or of the same race and the periodic array that P type thin layer alternately rearranges, be called the super lattice of receiving.

If in nano-substance adjacent receive grain about, front and back, the large scale line segment of (X, Y, Z) three directions all is a nanometer scale up and down, then should " zero dimension " if the electronics of intragranular received possess certain energy, electronics just can enter or overflow receives grain, and this just is called " tunneling effect ".It can produce the moving and localization of electric guided wave.It is different with the microelectronics system; Its electronics can not absorb continuous energy, can only absorb discrete energy.

The condition of electron tunneling is exactly that the energy eU of electronics must can E greater than charging _CE _CCan be used as electronics when entering (or leaving) this individual system, the energy of being experienced by the electron repelling of previous same Bands negative electrical charge, thereby E _C" coulomb blockade energy " is otherwise known as.

Receive in the nano-substance grain valence electron between be concerned with; When being electronics of a certain space existence, just can not there be another identical electronics simultaneously; After first electronics injected in the system, if it is not removed, second electronics just can not inject.Can inject electronics in chronological order.In the two-dimensional array of quantum face, the transmission path of electronics can be got different directions, complicated behavior therefore occurs: two electronics may be compound, also may repel mutually.The space correlation and the time correlation of electron transport will appear like this.What be the time preface with the space preface is relevant, is to produce signal processing and storing process new feature.Because time correlation and space correlation with the anisotropy of presentation space array, have different tunnelling characteristics at different directions.

Nano-substance is except having the relevant and statistical property of significant quantum state, and what other were main also has:

1) fluctuation of charge carrier; In the phase coherence range scale, do not lose the phase information of charge carrier.When system dimension was suitable with characteristic scattering free path, carrier transport was a ballistic, and tangible interference, diffraction effect are arranged.

2) the signal charge carrier also has orphan, polaron etc. except electronics-hole.The orphan receives a kind of distortion of lattice, and having neutral also has chargedly, can carry the signal transmission.It is a kind of charge carrier in the integrated circuit, and its excitation energy is lower than electrons/.Be concerned with between the orphan.

3) electricity lead and voltage between exist with irrelevant electricity of time and lead the aperiodicity fluctuation.It is not that thermal noise causes, but electric system is intrinsic.

Quantum state is the microscopic motion state of electronics in the material grainses such as each molecule or atom.When constituting the preface material by atom, molecule, ion or the material grains such as grain of receiving, valence electron no longer belongs to certain material grains, but does the communization motion in whole preface material.This causes the material grains energy level splitting to become can be with.Do not allow to exist the zone of energy state in the material grains, be called forbidden band (or band gap).The low energy area that the top in forbidden band is corresponding with valence electron is called valency Bands.The high-energy zone of valency Bands top is called and leads Bands.Lead the electron energy height on the electron energy rate of exchange Bands top at the bottom of the Bands, their difference equals energy gap Eg, and Eg is also referred to as band-gap energy.The atom average life span that is in excitation state is 10 ^-11S-10 ^-8Between the s, be unsettled.

Electronics in the atom can by with the mode generation energy level transition of extraneous positive energy exchange.Electron transition is carried out energy exchange with the form of heat energy, is called thermal transition.If the energy of exchange is luminous energy or electric energy, then be called optical transition.There is spontaneous emission (Spontaneous emission), the stimulated radiation (Stimulated emission) of light in the system for a large amount of atoms compositions and be excited to absorb (Stimulated absorption).

Material can not return the state that is excited of the particle energy level of oneself by radiative decay, is called metastable state.It is much more stable than material excitation state.

Have metastable some material, be called metastable state material (or being called matrix).Have only it just can realize population inversion and cause light amplification, and as the operation material of laser.It can be gas, solid or liquid.Its average life span can reach 10 ^-3The order of magnitude of s-1s.

Can encourage the metastable state material, finish the outside resources of population inversion task, be called pumping source.It can be power supply or light source etc.

If E ₁Be ground state (energy is minimum); E ₂And E ₃Be excitation state (energy is higher).Suppose E ₂Be metastable state.Pumping source can be with ground state E ₁On electronic pumping to excitation state E ₃On, thereby E ₁On electron number reduce.Because E ₃The electron lifetime of attitude is very short, and electronics will be transferred to metastable state E in the mode of radiationless transition soon by collision ₂On.Because E ₂Life-span is long, has just accumulated the particle of a large amount of upper state on it.Be metastable state E ₂Population N ₂Constantly increase, cause N ₂Greater than ground state E ₁On population N ₁, realize the counter-rotating (Fig. 2) of population between metastable state and the ground state.

If p (v) be the incident optical energy metric density of frequency v, N ₁For being in the population density of lower state, N ₂For being in the population density of upper state, (d N ₂₁/ dt) _FromFor in the unit interval from energy state E ₂Get back to energy state E ₁Population density (also being the photon number density of spontaneous emission in the unit interval);

(d N ₂₁/ dt) _From=A ₂₁N ₂(1)

A wherein ₂₁Be spontaneous emission coefficient, represent that a particle spontaneously returns the low energy probability of state from upper state in the unit interval.

(d N ₂₁/ dt) _{Be subjected to}For in the unit interval from energy state E ₂Get back to energy state E ₁Population density (also being the photon number density of stimulated radiation in the unit interval);

(d N ₂₁/ dt) _{Be subjected to}=B ₂₁P (v) N ₂(2)

B wherein ₂₁P (v) is the stimulated radiation coefficient, represents that a particle absorbs photon from upper state and transits to the low energy probability of state in the unit interval.

(d N ₁₂/ dt) _InhaleFor in the unit interval from energy state E ₁Transit to energy state E ₂Population density (also being systemic photon number density of unit interval);

(d N ₁₂/ dt) _Inhale=B ₁₂P (v) N ₁(3)

B wherein ₁₂P (v) is the absorbed radiation coefficient, represents that a particle transits to height from lower state absorption photon probability of state is arranged in the unit interval.

If the ground state level of metastable state material is E ₀The following energy level E of population inversion ₁(E ₁＞E ₀) not in ground state, and in excitation state.Because excitation state E ₁Population originally seldom, as long as metastable state E ₂On particle accumulation is arranged slightly, just be easier to realize E ₁And E ₂Between population inversion (Fig. 3).

Population inversion must have internal factor metastable state and external factor pumping source.Electron transport must be the nonequilibrium process that circulation comes and goes in the particle.

A kind of metastable state material has several to the population inversion between particular level, correspondingly sends the laser of several wavelength.

The metastable state material causes that the photon of stimulated radiation is spontaneous generation.Its phase place, polarization direction, the direction of propagation etc. all are rambling.Stimulated radiation after it amplifies also be generally at random, random.Choose the photon that fixing a kind of photon of the direction of propagation and fixed frequency amplifies and suppress and abandon other, the high light (laser) that can obtain to have directivity and monochromaticjty.The mirror surface of installing respectively at the two ends of metastable state material and the space of formation thereof are called laserresonator, are called for short resonant cavity.This is a completely reflecting mirror to one of mirror surface, and its reflectivity is as far as possible near 1; Another reflecting surface is exported as laser, be the half-reflecting mirror of partial reflection, part transmission, but its reflectivity is also very high.It amplifies light beam repeatedly in the metastable state material, guarantee the high brightness of laser.By changing resonator parameter, can improve laser direction, monochromaticjty and power etc.

Research and elaboration realize the character of laser and the theoretical foundation science of inner link and objective law etc. thereof by nano-substance, are called nanometer laser and learn.

The technology that principle that nanometer laser is learned and rule are applied to all trades and professions is called the nanometer laser technology.Follow the laser system of quantum mechanics rule, be called the nanometer laser system.The nanometer laser material device that utilizes nanometer and laser technology to make is called the nanometer laser device.

It is enough little that the large scale direction of nanometer laser material is received between the grain distance, is the quantization effect, so macroscopical charge number and energy are quantized.

Distance in the existing laser material between the particle is not enough little everywhere, does not have the quantization effect, so the charge number and the energy of macroscopic view are continuous.

Nano-substance solidifies with two kinds of different modes: preface material attitude and non-preface material attitude.Its essential distinction: receive the grain arrangement be long-range orderly or long-range unordered.

Liquid free energy G when object ₁With solid-state free energy G _sWhen equating, be in thermodynamic equilibrium state, this temperature is exactly the fusing point T of this object _m

The preface material has definite fusing point (the preface material is to the liquid critical temperature that changes of non-preface material).Transformation from solid-state preface material to liquid non-preface material suddenlys change.Vice versa.But the transformation of non-preface material from solid to liquid is transition gradually, do not have fusing point or the solidifying point determined.Vice versa.

In the small scope in liquation, exist a tight contact and a regularly arranged collective that receives, be called shortrange order group.They are in the moment appearance, and pop-off rises one after another, among the Protean state.Shortrange order group constantly changes in the two-phase liquation, is called structure and rises and falls or rise and fall mutually.The shortrange order group that rises and falls mutually in the solution is called the preface embryo.It is the plumule of preface material.But the grain of receiving on a large scale in the liquation is a disorder distribution.

It is certain otherwise be higher than fusing point T that liquation forms the temperature of preface material _m, the solid-state free energy of this sequential material is lower than its liquid free energy.The difference of the two free energy has constituted the actuating force that the preface material solidifies on the one hand.Because the preface embryo constitutes new surface, form surface energy on the other hand; It raises the free energy of system, is the resistance that the preface material solidifies.When temperature T is equal to or slightly lower than fusing point T _mThe time, discontinuous variation (BC) appears in the volume of liquation, separates out the preface material.Do not mixing under the situation of preface material transformation, the preface material also is thermodynamically stable.Solid-state receive the grain Mi Dui close, active force is bigger, so the coefficient of expansion of preface material is littler than its liquid usually.If temperature is less than T _mAnd decline sequential material is not separated out, still according to diminishing ， Shrink little (BE) continuously to presenting solid-state temperature T fully with liquid phase with the coefficient of expansion _gThe time, the coefficient of expansion suddenlys change to identical with the solid-state coefficient of expansion of non-preface material.T＜T _gThe time, form non-preface material (Fig. 8).

T _gNot a constant, change within the specific limits along with the cooling rate speed.Compare with the preface material, the density of non-preface material is less, and fast more then its density of cooling rate is more little.The completely crued transition temperature T of non-preface material _g, be called the complete solidification temperature of non-preface material, be called for short non-preface condensation point.

When the nano-substance liquation is between its non-preface condensation point and its fusing point, be called supercooled liquid.Though it is it is thermodynamic (al) poised state, unstable.Supercooled liquid and stable liquid state do not have the difference of essence.Just temperature is low more, and viscosity is big more, and the motion that the grain of receiving is made long distance is more difficult.Being converted to the lower preface material of another energy from supercooled liquid is always certain potential barrier U and limits.If when liquation has the energy that surmounts this potential barrier, it will change the preface material into.If the aspect ratio energy of thermal motion of this potential barrier U is abundantly big, then the probability that should change is minimum.It will form non-preface material.

At T _gIt is zero that near viscosity reaches the probability of receiving the grain transposition or spreading.Non-preface material is at this moment similar in appearance to the preface material, so be lower than T _gBoth coefficients of expansion are similar.

The cooling rate difference of liquation, the non-preface condensation point that the grain of then receiving reaches is also different.This is that the grain of receiving under lower temperature still can be adjusted its position, changes its coordination environment because at a slow speed when cooling off, so viscosity is lower and obtain more compact structure, thereby density is also bigger.Therefore non-preface material formation condition is that cooling rate is fast and viscosity is big; It has little time to receive the grain sort.And the liquation condensation is slow, when viscosity is low, just have the sufficient time to form the preface material.

In the supercooled liquid of uniform temperature, the solid-state free energy of material is lower than liquid free energy.If wherein the preface idiosome that occurs is long-pending is V, surface area is S, and solid-state and liquid two-phase unit volume free energy difference is Δ Gv, and the surface energy of unit are is σ, then always being changed to of system's free energy:

ΔG＝VΔGv+Sσ????????????????????????????????????????????(4)

If occur the spherical preface embryo that radius is r in the supercooled liquid, the free energy change that it causes turns to:

ΔG＝(4πr ³ΔGv)/3+4πr ²σ????????????????????????????????(5)

Getting r from (5) formula is some critical radius value R _KThe time, Δ Gv is a maximum.To (5) decline branch and make it equal zero, critical radius be:

R _K＝-2σ/ΔGv?????????????????????????????????????????????(6)

As preface embryo r＜R _KThe time, along with the increase of preface embryo size r, the free energy of system increases, and the preface embryo becomes unsettled.Be the instantaneous formation of preface embryo, instantaneous again disappearance.As r＞R _KThe time, then along with the increase of preface embryo size, the free energy of system reduces, and the preface embryo can spontaneously be grown up into preface material stable and that have certain certain size in liquation.It can not disappear again.Work as r=R _KThe time, the preface embryo both may disappear, and also may grow up into stable small size preface material.The difference of the free energy of the solid-state and liquid two-phase of unit volume is the equivalent radius of maximum sequential embryo, is called critical preface material radius (Fig. 9).

Equivalent radius is the preface embryo of critical preface material radius, is called critical preface nuclear.Radius is called preface nuclear greater than the preface material of critical preface nuclear.Have only in the supercooled liquid and larger-size the fluctuating mutually to occur and just might form preface nuclear.Form the process of preface nuclear in the liquation, be called forming core.If it is identical that the preface nuclear probability of cenotype appears in each zone of liquation, be called homogeneous nucleation.Forming core constantly condenses to be received grain (or atom etc.) and continues growth process in the liquation, be called and grow up.

Material preface material from liquation forms the mandatory rule of preface material: at first form preface nuclear (or directly utilizing solid-state preface nuclear) in the liquation of high purity substance, the grain of receiving that constantly condenses in the liquation by these preface nuclears also continues slowly to grow up, and just becomes the preface material of large scale gradually.Here it is preface material law.

Through accurate pointing and to have the one dimension direction at least be the solid-state preface nuclear of large scale, be called the seed preface.Little thread seed preface is called seed preface bar; The sheet seed preface of small pieces is called seed preface sheet; The cylindric seed preface of fritter is called seed preface piece.

Resonance effect between photon and the metastable state material is the luminous physical basis of laser.Because the adjacent little space yardstick of receiving distance between the grain in the nanometer laser device, electronics can be subjected to the effect of contraction of the Coulomb force of atom when entering or leave.If when certain communization electronics has the Fermi level identical with the outer field electronics of atom, they will repel mutually, can not be compatible; Have only the electronics of higher discrete energy levels just can enter this nanometer laser system.Its electricity is led the electron transition that will show between the different Fermi levels, and is quantized step conductivity.Because the capacitor C that the plastochondria of receiving is is very little, coulomb blockade can E _CCan be much larger than energy of thermal motion; The process of its charging and discharge just presents discontinuity; Reach quantization.The collective transmission continuously of electronics this moment, this is owing to receive being with by discrete energy level of grain and replace.This electronics must be called the single electron tunnelling one by one by receiving a slit.Therefore conductivity G is not a constant, but h/e ²Integral multiple.The electric quantization of leading that Here it is.Single electron tunnelling and conductance are the characteristic that had of nanometer laser material and the basis of application.

Nanometer laser is a kind of electromagnetic wave, can produce polarization during by medium.The intensity of nanometer laser is very high, and polarization is along with electric field takes place non-linearly to change.In isotropic medium, polarization intensity P and electric field strength E are equidirectional, polarization intensity can be launched into the progression of electric field strength:

P(E)＝ε ₀(xE+x ₂E ²+x ₃E ³+x ₄E ⁴+...)?????????????????????????????(7)

ε in the following formula ₀Be permittivity of vacuum, x is a linear polarization rate.

Draw from quantum-mechanical theory, the ratio of nonlinear terms and linear term is in (7) formula in optical field

x ₂E ²/ xE=E/E _Atom(8)

E is the electric field strength of incident light in the following formula; E _AtomAverage field intensity for atom inside is about 10 ¹¹V/m.

(7) the quadratic nonlinearity item P in the formula ₂Expression; The pass of it and field intensity is: P ₂=ε ₀x ₂E ²(9)

If being the monochromatic light of ω, angular frequency incides on the nonlinear dielectric, then field intensity E=E ₀Cos ω t (10)

Substitution (9) formula gets P ₂=ε ₀x ₂(E ₀Cos ω t) ²=ε ₀x ₂E ₀ ²(1+cos 2 ω t) (11)

(11) formula first representative in the right " direct current " item, promptly time-independent polarization intensity.Its expression: occur positive and negative surface charge respectively on two surfaces of medium, form square E with incident intensity ₀ ²The constant potential that is directly proportional is poor.This effect is called optical rectification.

(11) second eelctric dipole distance of representing frequency to equal 2 times of fundamental frequencies in formula the right, it is called frequency-doubled effect (secondary optics harmonic effect).

If nonlinear dielectric is isotropic or has the preface material of symmetrical centre that when then electric field was reverse, polarization intensity was also reverse.P is the odd function of E, and the coefficient of all the even items in the series expansion (7) equals zero.Therefore such medium can not produce second harmonic.

Have only preface material or crystal could produce second harmonic with symmetrical centre.If only consider the divalence polarization intensity P that causes by electric field ₂Size, with x ₂Be interpreted as the effective polarizability x of second order _Eff, P then ₂=ε ₀x _EffE ₀ ²(12)

x _EffAlong with preface wood property matter and light in the preface material the direction of propagation and change.When phase matched, fundamental frequency light is identical with the propagation velocity of frequency doubled light, fundamental frequency light in the preface material on the way the frequency doubled light that excites of each point along optical axis direction identical phase place is arranged when running to exit facet; Thereby reinforcement obtains good frequency multiplication effect mutually.Its conversion efficiency and the effective polarizability of second order square, the preface material thickness of active area square and the incident light intensity be directly proportional.

In anisotropic preface material, owing to there is birefringence, can utilize the refractive index difference of two bundle refract lights to come the compensation of dispersion effect, realize phase matched.By this frequency-doubling method and technology, can realize high light beam quality, all solid state, miniaturization, high efficiency optical fiber nano laser.

Nano laser includes the resonant cavity that the nanometer thin rete with reflection function on the nanometer active layer of nanometer grade thickness and active layer both sides constitutes usually.The nanometer active layer can be the N type, also can be the P type.When applying forward bias voltage, electronics is injected into the nanometer active layer from N type thin layer; The hole is injected into the nanometer active layer from P type thin layer.The homojunction that produces owing to Bands crack difference or the existence of potential barrier of heterogenous junction make the electronics that is injected in this active layer and hole can not spread and be limited in the nanometer active layer, so charge carrier are as easy as rolling off a log in nanometer active layer realization population inversion.Even have only very little electron transition, electronics in the active layer of nanometer grade thickness (5-100 nanometer) and hole concentration also can be very high, and the gain of light that the laser concussion produces is proportional to institute's injected electrons and hole concentration; So in nanometer layer, just can obtain very big gain with very little electric current.On the other hand, the refractive index of the refractive index ratio nanometer thin rete of narrow band gap active layer is big, and light wave is to the big regional centralized of refractive index, so light wave also is limited in the active layer.When the electronics that forms the counter-rotating distribution in the active layer transits to valency Bands from leading Bands, send photon with hole-recombination.The active layer of these photons between the nanometer thin rete comes and goes operation, constantly obtains the gain of light.Loss is minimum in the nanometer resonant cavity, and the efficient of nanometer laser is just very high.Nano laser is followed principle of quantum mechanics, aspect preparation and the use great difference is being arranged all with existing microelectronic component.

Existing various lasers bulky, efficient is low, as CO ₂Laser, YAG laser and argon ion laser etc.The light pulse that utilizes lens nano laser can be sent focuses on the quartzy preface material, to replace existing lamp pump solid state laser or semiconductor pumped solid state laser.

Nano laser is because non equilibrium carrier presents quantum effect, and it is compared with existing laser, has excellent specific properties such as threshold current density is low, electro-optical efficiency is high, power output is big.By growth strain quantum face, make the non-laser of growth receive the extension material of lattice coupling and be achieved, widened the nano laser wave-length coverage.Because the active area of nano laser is less than 100 nanometers.Therefore it has very little threshold current and current density, makes device operation current drop to minimum, even has only tens electronics to move the electric current of formation; Guarantee nano laser continuous operation at room temperature.

In the semiconductor nano laser structure, key position is the atomic fine texture of nanoscale length and nanosecond time; It demonstrates the Quantum Properties of wave mechanical quantum effect of nano material and electronics; If suitably choose the nanostructure parameter, just can realize and existing body material or double heterojunction (Double Heterostructure, DH) the different good electric-light characteristic of semiconductor laser.Following nano-substance is also referred to as nano material.

1. in the solid nano laser, the active ions Inlaid that plays the stimulated radiation effect is embedded in the nano material matrix of preface material or non-preface material and so on, and the density of active ions is about 10 ¹⁹Individual/cm ³-10 ²²Individual/cm ³, more much bigger than the particle density of gas operation material.To make bar-shapedly as the matrix (preface material or non-preface material) of nanometer laser, both ends of the surface are polished to optical flat, and have the good depth of parallelism.Plate the reflection nanometer film in both ends of the surface, just constitute optical resonator, also can adopt two speculums to constitute optical resonator in addition.The solid nano laser generally adopts the optical pumping pumping, and pumping source can be continuously luminous or pulsed is luminous; Light source is xenon lamp or high-pressure mercury-vapor lamp normally.Adopt nanotube diode pumping (DPSS) to have very high pump power and reliability.Light source can also be used semiconductor light sources in addition, comprise semiconductor light-emitting-diode (Light EmittingDiode, LED) and semiconductor laser diode (Laser Diode, LD); Perhaps fiber laser light sources such as (Optical Fiber LASER).

When mixing the foreign atom of minute quantity in the space lattice of some preface material laser, can produce laser transition.For example ruby nanometer laser rod is by the Cr that is mixed with ten thousand/(by mass) ₂O ₃Artificial white stone (Al ₂O ₃) the preface material makes.Al in the preface material ³⁺By Cr ³⁺Replace; Cr ³⁺Density be about 1.65 * 10 ¹⁹Individual/cm ³The wavelength X of laser transition=0.6943 micron.In ruby, active ions are Cr ³⁺Ion.

The yttrium-aluminium-garnet of neodymium-doped (Nd:YAG) preface material is a kind of effectively nanometer laser material, the wavelength X of laser transition=1.06 micron.Its active ions are Nd ³⁺Ion.In addition, non-preface material glass, CaF ₂Preface material, SrF ₂Preface material, CaWO ₄Many nano materials such as preface material also can be used as the matrix of neodymium.These nano materials or crystal impurity can be ultra microns.Following table has been listed the material and the wavelength thereof of some nanometer lasers.

2. the dyestuff nano laser is a kind of with the nanometer laser device of molecule as the basic granules energy level.The operation material of dyestuff nano laser is that the liquid state in the nano dye solution is received grain.Molecular energy level than the energy level complexity of atom many.In molecule, except the energy of electronics, also has vibration relatively between each atom of ingredient; Whole molecule also will rotate.The energy of nano dye molecule also is made up of this three part, promptly

E=E _Electronics+ E _Vibration+ E _Rotate(13)

This three portion of energy all is quantized.Electron energy E wherein _ElectronicsQuantization at interval maximum, be about several electron-volts; Vibrational energy E _VibrationQuantization be about 1/10eV at interval; Rotational energy E _RotateQuantization at interval minimum, than also little at interval two orders of magnitude of quantization of vibrational energy.

Among the nano dye molecular entergy level figure (Fig. 4), S ₀Be ground state, S ₁And S ₂Be excitation state.S ₀, S ₁, S ₂Between large-spacing since the quantization of electron energy form.S ₀, S ₁, S ₂Itself is made up of many intensive vibrations and rotational energy level again.In molecular spectrum, the transition between the different-energy attitude is (as S ₁And S ₀Between) produce the bands of a spectrum of forming by the intensive spectral line of cluster.

The molecule of the overwhelming majority is in the minimum vibration, rotational energy level of ground state.After having absorbed external photon, molecule just from these energy level transitions to S ₁On the higher vibration of attitude, the rotational energy level (A among Fig. 4 → b).Molecule also might be from the ground state transition to S ₂Attitude is fallen S more soon ₁On the attitude.During heat balance because frequent energy exchange, at S ₁On each vibration of attitude, the rotational energy level, molecule will redistribute, in the extremely short time (about 10 ^-11Second) interior molecule distributes on each energy level and follows Boltzmann distribution law.The molecule that great majority are excited decay to S radiationlessly ₁On the minimum vibration of attitude, the rotational energy level (b among Fig. 4 → B).Like this at B and ground state S ₀Higher vibration, rotational energy level (just realized population inversion between a) among Fig. 4.When counter-rotating reaches threshold values, just produce laser.All nano dye lasers all are to use the optical pumping pumping, and the wave band of major requirement optical pumping output is near the absworption peak of dyestuff; It can be with pumping such as xenon lamp or nitrogen molecular laser, argon ion laser, also available nano laser pumping.

The following energy level of laser transition is S in the dyestuff nano laser (Fig. 5) ₀Higher those vibrations, the rotational energy level of attitude.Because S ₀The vibration of attitude, rotational energy level have a distribution, can utilize the tuned cell (grating, prism etc.) that inserts in the resonant cavity to change the frequency of output laser.The light beam of the adjustable dye nano laser of laser pumping and resonant cavity axle form a low-angle (about 3 °).Resonant cavity is made up of reflecting grating G and a mirror M that is coated with the nanometer deielectric-coating.Rotating shutter just can change the frequency of output laser.When not inserting a Fabry-Perot (F-P) etalon in the resonant cavity, the live width of output laser is 50 microns, behind the insertion etalon, can obtain the single-mode laser (Fig. 5) that live width is about 1 micron.

Following table is listed the tuning range (unit: micron) of some nanometer laser dyestuff.

Nano dye	Tuning range roughly		Nano dye	Tuning range roughly		Nano dye	Tuning range roughly
								Cresol-purple	??0.64-0.7		Ruo Ming-6G	??0.56-0.65		Cumarin	??0.44-0.49
Acridine red	??0.6-0.63		Receive fluorescein	??0.52-0.57		Receive salicylate	??0.39-0.42
								Rhodamine-B	??0.58-0.69		The tetramethyl shape ketone that looses	??0.44-0.54		??POPOP	??0.38-0.44

3. the semiconductor nano laser is by nanometer P in the semiconductor preface material ⁺N ⁺Knot (or PN junction etc.) constitute.Compound semiconductor nano material wherein: periodic table of elements tetrels is a covalent bond, for example diamond, Germanium, silicon, selenium etc.Then semiconductor bielement nano material compounds such as family of four families-four, family of three races-five and family of two families-six have more and more stronger polar covalent bond; Also have semiconductor ternary, quaternary and polynary nanometer material compound.

That utilizes that the heterostructure of semiconductor nano material causes can be with the poor of discontinuity and refractive index, can make the continuous operation at room temperature of semiconductor nano laser.It is applied to optical fiber communication, will have extremely excellent performance.Semiconductor nano material is the core material that constitutes nano laser.

Flick assorted nanometer laser diode and form (Fig. 6) by PN junction and two electrodes.Its structure is basic the same with laser diode (LD).The nanometer laser diode is to be made of the semiconductor preface material that mixes; And LD is made of the semiconductor crystal that mixes.This is essential distinction between them.

The semiconductor nano laser also adopts the preface material of gallium (Ga), arsenic (As), indium (In), phosphorus (P) and aluminium compounds such as (Al) or non-preface material to make usually.Adopt heavily doped GaAsPN knot, use nanometer P ⁺N ⁺Expression.P-GaAs and N-GaAs are formed nanometer P with the semiconductor diffusion technology ⁺N ⁺Knot (Figure 11); And the non equilibrium carrier electrons/injected this knot, can realize the carrier number counter-rotating.This phenomenon is called charge carrier and injects.At P ⁺District and N ⁺Carrier concentration is high in the district.P ⁺District Fermi level E _FpBe among the valency Bands; N ⁺District Fermi level E _FnBe in and lead among the Bands.They have unified Fermi level E _F=E _Fp=E _Fn, charge carrier is in equilibrium state, and its barrier height is qV _nAs nanometer P ⁺N ⁺Tie when adding forward voltage V, the Fermi level in P district and N district is departed from, and qV=E is arranged _Fn-E _FpThe difference of obvious two Fermi levels has been strengthened the diffusion tendency of charge carrier, makes a large amount of charge carriers inject P ⁺N ⁺The interface forms carrier number counter-rotating distribution in the injection region.

The compound generation radiation photon in non equilibrium carrier electronics-hole in the injection region.These photons will cause that the non equilibrium carrier that is in the counter-rotating distribution produces and will be excited compound and emission stimulated radiation photon.But realize that it is the necessary condition of junction semiconductor nano laser that the carrier number counter-rotating distributes; In order to obtain the necessary and sufficient condition of relevant nanometer laser radiation by force; The semiconductor nano laser also needs optical resonator.The nano laser resonant cavity can utilize and nanometer P ⁺N ⁺The orthogonal preface material of junction plane cleavage surface constitutes Fabry Perot resonator.The preface material cleavage surface of one end plates the high-performance reflectance coating, and the preface material cleavage surface of the other end is as output and reflection end; Be used to realize the nanometer laser concussion.The zone of radiation nanometer laser is called active area.

3.1 the homojunction nano laser is that P-GaAs and N-GaAs are closely linked, and forms a preface material PN junction and built-in field.During forward outside applying (the P district connects positive pole, and the N district connects negative pole) voltage, this forward voltage makes the PN junction built-in field reduce (Fig. 6).Under the non equilibrium carrier effect, electronics spreads to the P district from the N district through PN junction; Spread to the N district from the P district through PN junction in the hole; Forward current appears because charge carrier injects.Nanometer laser diode resonant cavity can utilize and P ⁺N ⁺The orthogonal preface material of junction plane cleavage surface (110 face) constitutes Fabry Perot resonator.The cleavage surface of one end (110) plates the high-performance reflectance coating, and the cleavage surface of the other end (110) is as output; The concussion of realization nanometer laser.

3.2 heterojunction GaAs semiconductor nano laser is to generate another heavy doping P on preface material P-GaAs and preface material N-GaAs ⁺-Al _xGa _1-xAs or N ⁺-Al _xGa _1-xAs preface material forms semiconductor single heterojunction GaAs nano laser (Figure 12) or double heterojunction GaAs nano laser (Figure 13).The heterojunction semiconductor nano laser is not from P ⁺N ⁺The interface radiation laser; But from P ⁺District's radiation laser.P ⁺The about 10-2000 nanometer of district's thickness.

Owing to the poor nanometer homojunction that produces in nano material Bands crack or the existence of potential barrier of heterogenous junction, make the electronics that is injected in this active area and hole can not spread and be limited in the nanometer active area, so charge carrier is as easy as rolling off a log realizes population inversion at the nanometer active area.Even have only very little electron transition, electronics and hole concentration in the active area (10-100 nanometer) of nanometer grade thickness also can be very high, and the gain of light that the laser concussion produces is proportional to institute's injected electrons and hole concentration; So in nanometer layer, just can obtain very big gain with very little electric current.On the other hand, the refractive index of the refractive index ratio nanometer thin rete of narrow band gap active area is big, and light wave is to the big regional centralized of refractive index, so light wave also is limited in the active area.When the electronics that forms the counter-rotating distribution in the active area transits to valency Bands from leading Bands, send photon with hole-recombination.Heterojunction is continuous operation at room temperature.

4. the optical fiber nano laser is as laser medium with nano optical fibers itself; Its resonant cavity is by two end faces bonding chamber sheets of nano optical fibers or plate that nano thin-film constitutes.It also can directly inscribe the nano optical fibers Bragg grating as resonant cavity on the nano optical fibers end face.Its cavity body structure is simple, and the nano optical fibers softness, can be coiled into arbitrary shape in minimum profile curvature radius scope outside sweep.Small and exquisite modular high-power semiconductor laser of volume that its selection emission wavelength and nano optical fibers absorption characteristic are complementary or semiconductor nano laser are as pumping source; Be easy to realize high efficiency and high power.Therefore this nano laser is simple in structure, and volume is little, and is in light weight, flexible and convenient to use, and nano optical fibers is directly exported laser.It will obtain extensive use in fields such as high-precision laser processing, optical communication, laser chemistry, laser radar system, space technology, laser medicines.

The optical fiber nano laser can be divided into single layer optical fiber nano laser and double-deck optical fiber nano laser.Double-layer nanometer optical fiber is a kind of nano optical fibers with special construction.It has increased an inner cladding (the inner cladding shape can be circle etc.) than individual layer nano optical fibers, and the lateral dimension of inner cladding and numerical aperture are all much larger than fibre core (Fig. 7).Doped with rare-earth elements (Yh, Nd, Er, Tm etc.) in the fibre core of double-deck optical fiber nano laser; Because inner cladding surrounds the periphery of single mode nanometer fibre core, pump light launch in inner cladding and is also repeatedly passed through the nanometer fibre core and be doped ion and absorb, thereby pump light is converted to the single mode nanometer laser efficiently.The size of inner cladding generally all should be greater than 100 microns, feasible focal spot after coupled lens focuses on is that the multimode pump light about 100 microns can be coupled in the monomode fiber effectively, and the numerical aperture of inner cladding is generally greater than 0.36 millimeter, the ability of collecting pump light is strong, thereby can guarantee that the high energy pump light is coupled into inner cladding efficiently.Because the cross sectional dimensions of the inner cladding of double clad nano optical fibers and numerical aperture are all enough big, semiconductor nano laser is by behind the beam shaping, can be coupled into inner cladding efficiently, by selecting suitable inner cladding parameter and shape, realize efficient, high power laser light output, conversion efficiency can reach more than 0.7.

The doubly clad optical fiber nano laser adopts elongated dopen Nano optical fiber itself as gain media, and surface to volume ratio is very big; At least be more than 1000 times of existing solid laser medium, so heat dispersion is very good.The pump light of doubly clad optical fiber nano laser transmits in the inner cladding waveguide in addition, and the power indiffusion helps keeping the high power density optical pumping.This is very favourable for last conversion nano laser.By the different rare earth ion that in the nanometer fibre core, mixes, can realize the laser output of blue light (mixing Tm), green glow (mixing Er) and ruddiness (mixing Pr).

5. the nanometer laser material is only slow in its speed of growth, when free space being arranged on every side, could form well-regulated geometry; Because the grain of receiving is different, formation condition (speed of the temperature of liquation, pressure, denseness and condensation etc.) is different, can form various preface materials.This technology should possess two preconditions: one is to satisfy the growth mechanism that nano material forms; The secondth, should satisfy the technological parameter that nano material forms.

Material (comprising dopant) remains on non-preface condensation point T through after the long-time heat _gWith fusing point T _mBetween, and the material that is about to solidify vibrated or stir; Rely on outside intake to impel seed preface or preface nuclear to form in advance on the one hand, impel seed ordinal number order to increase on the other hand.With mechanical means crucible vibration or speed change that the subcooled liquid after the heat is housed are rotated; Or carry out ultrasonic Treatment etc.; All can form good preface material.

The impurity of preface material growth meeting generation regional area is inhomogeneous in gravitational field.Can adopt growth preface material under the additional high-intensity magnetic field condition; Because magnetic field can suppress the liquation convection current or avoid impurity inhomogeneous.In silicon preface material and GaAs preface material, adopt the neutron transmutation technology also can obtain uniform preface material in addition.

Nanometer laser material basic generation technology: certain high-purity material melts in containing the fusion crucible that draws preface material equipment of smelting furnace; When the temperature of this material remains the state of its fusing point (or hanging down a bit a little), by the mechanical device (for example clamper) of the seed preface that hauls this kind material (can be seed preface bar, seed preface sheet or seed preface piece) very lentamente along rotation counterclockwise, with immerse in the fused solution of this kind material the seed preface around space temperature remain on fusing point to time between the non-preface condensation point and be pulled upwardly; At first contacting melted material on the seed preface will and receive face angle and born of the same parents' the lattice shape etc. received received according to the face of receiving of this seed preface and at first be formed with the preface material that rule, long-range order are arranged; Form preface material ingot then rallentando along with being pulled upwardly.

Nanometer laser material epitaxy generation technique: with the seed preface (seed preface bar, seed preface sheet or seed preface piece etc.) of certain high-purity material as preface material substrate, allow the atom of this high-purity material be arranged in regularly on the preface material substrate, progressively form have certain type from level to level, function, thickness and than the preface material layer of complete structure.It is divided into chemical vapor deposition (CVD) technology and molecular beam epitaxy (Molecular Beam Epitaxy, MBE) technology.

In pure laser preface material, suitably mix trace impurity, can make various different purposes, nanometer laser device that precision is high.

Nanometer laser annealing is that the nanometer laser bundle is focused on any zone that needs annealing, even can anneal to the zone of any nanometer scale, can remove effectively to receive the dislocation of grain and the stacking fault of material.It can carry out in air.It is better than existing thermal annealing quality, and expense is low.

5.1 the electronic state of laser quantum point (laser preface material particle) on the nano-grade size of three linear independence directions all is quantized." tunneling effect " of the electronics in quantum dot will produce the moving and localization of electric guided wave.Be that its restriction electronics makes its electronics with the zero dimension degree of freedom and discrete number and energy level.The laser quantum point has unusual property, and the electric current of the laser quantum point of flowing through increases in the quantum unit or when reducing one or several electronics, electric current changes can reach one or several order of magnitude.The electronics that energy is lower than potential barrier also has certain probability and enters or leave the laser quantum point.Electron absorption certain energy tunneling barrier must have a hole with identical energy at the other end of potential barrier.

The nanometer laser material only avoids thermal noise energy to surpass the tunnelling energy of electronics, and coulomb blockade and electron tunneling quantum effect just appear in laser quantum point.This just requires the minimum and resistance of tunnel junction electric capacity greater than quantum resistance; Promptly require tunnel junction face kind minimum.If the grain of receiving is of a size of 10 nanometers, suppose that it has 10 ⁵Individual atom, the electric capacity that experimental results show that its tunnel junction are 1 Ah's farad (1aF=10 ^-18F), at high temperature also there is coulomb blockage.Therefore the grain of receiving is just had ready conditions and is become the laser quantum point.The laser quantum point has only nano-grade size, so be in nanoscale without any the adjacent distance of receiving between the grain of one dimension large scale direction, is called the zero-dimension nano laser material.For example nanometer laser particle and nanometer laser elementide (or nanometer laser cluster) etc.Powdery object by numerous laser quantum point set forms is called the nanometer laser powder.

The preparation method of laser quantum point: physical method is vacuum evaporation condensation method or mechanical ball milling method (combine with grinding to pulverize, realize the powdered of preface material).Chemical method is vapor phase method and solid phase method.Using vaporization condensation process and vapor phase method are divided into resistance heating, heated by plasma and LASER HEATING etc.

Laser preface material particle is compared with existing monocrystal nano particle, has remarkable excellent characteristic, is one of important materials of making Laser Devices.

Semi-conductive laser quantum point must insulate with matrix.Laser quantum point is coupled by tunnel junction and nano-electrode or nanometer electrical lead, can be made into nanometer laser diode and nanometer laser device.Wherein the laser quantum point is also referred to as laser coulomb island (or laser center island).Utilize electrochemical method or semiconductor nano process technology, can produce semiconductor laser and receive grain, and can generate needed insulating barrier outside the grain receiving, form semiconductor nano laser diode with laser quantum point feature with quantum effect.Extreme ultraviolet laser lithography (EUV) can make the live width of photoetching less than 70 nanometers; Far be superior to the limit of the photoetching technique (Photo Lithography) of existing microelectronic integrated circuit.

5.2 when the diameter of laser quantum line (laser nano silk) is little to a certain degree the time, electronic motion is limited in the axis direction of lines, and electronics can not with the plane of axis normal on move, promptly limit electronics and have only the motion in one dimension degree of freedom.It is exactly the laser quantum line.The laser quantum line has the electronics of the discrete number of one dimension and discrete energy level.When electronics moves, there is the coulomb blockade effect on the axis direction of laser quantum line; And can form the electronic laser tunneling effect by laser battle array tunnel PN junction and electrode or lead coupling.The laser quantum line has the adjacent distance of receiving between the grain on the large scale lines (it can be straight line or curve) of one dimension direction to be in nanoscale, is also referred to as the 1-dimention nano laser material.

In the nanometer laser material, the laser quantum line can be used as laser coulomb island (or laser center island), forms semiconductor nano laser diode or nanometer laser triode by laser tunnel junction and electrode coupling.It mainly is a quantum effect of using the laser quantum line, and its function is very similar to laser quantum point.Laser quantum line (or laser quantum point) can be made up of unimolecule.The semiconductor that this quantum wire is formed is called the laser molecular semiconductor.

The main generation method of laser quantum line (laser nano silk): the fusion crucible of certain high-purity laser material in the smelting furnace of crystal pulling apparatus melted, by haul many parallel to each other and perpendicular to the mechanical device of the seed preface of this kind laser material on ground (be its clamper install simultaneously many parallel and perpendicular to the independent seed preface of ground level), can control simultaneously these seed prefaces independently of one another very lentamente along rotation counterclockwise, and the seed preface that will immerse very lentamente in the fused solution of this kind laser material rotates up pull-up; At first contact the fusion high-purity laser material on the seed preface, keeping under the constant substantially situation of environment temperature, will according to the face of receiving of this seed preface and receive the face angle and receive born of the same parents receive lattice shape etc., be formed with the preface material of this laser material that rule, long-range order arrange; Form many independently laser quantum lines rallentando along with rotating and moving up then.

The laser nano silk is compared with existing monocrystal silk, has remarkable excellent characteristic, especially one of important materials of nanometer laser quantum element.

5.3 the electronic state of laser quantum face (laser nano film) on two linear independence directions all is the quantization of photoexcited state.Have the adjacent distance of receiving between the grain on the long face of large scale (it can be a planar section or curved sections) of two-dimensional directional and be in the laser quantum face of nanoscale, be called the two-dimensional nano laser material.It has the energy level of the two-dimentional electron motion degree of freedom and discrete number.Electronics moves on the large scale plane in the laser nano film, has the coulomb blockade effect; And can form the electronic laser tunneling effect by laser tunnel junction and electrode or lead coupling.The laser nano film has one dimension to be in the small size nanoscale, as laser nano film and laser nano plural layers etc.

Existing film can be divided into membrana granulosa and dense film by constituting and compactness extent.The middle film that micron-sized minimum gap is arranged is called membrana granulosa if film crystal grain sticks together.If there are the continuous film that is of a size of micron number magnitude crack in rete densification and intergranule, be called dense film.

The main synthetic method of laser quantum face: certain high-purity laser material is melted in containing the fusion crucible that draws preface equipment of smelting furnace, (its clamper can be installed many parallel and perpendicular to the independent seed preface sheet of ground level simultaneously by the mechanical device that hauls this kind material seed preface sheet, and can control these seed preface sheets independently very lentamente along rotation counterclockwise), very slowly the rotation seed preface sheet that will immerse in the fused solution of this kind laser material is pulled upwardly under a certain high temperature; At first contacting high-purity melted material on the seed preface sheet will and receive face angle and born of the same parents' the lattice shape etc. received received according to the face of receiving of this seed preface sheet and at first be formed with this material preface material that rule, long-range order are arranged; Form many laser nano films that separate rallentando along with rotating and moving up then.Other preparation methods also have: sol-gal process, vacuum vapor deposition method, magnetron sputtering method, electrodeposition process etc.

The laser nano film is compared with existing monocrystal film, has significant architectural feature, is the excellent material of making the laser nano multilayer film, one of important materials of the laser quantum element of especially integrated and complanation sensitivity; It also is the main material of multifunctional nano laser sensor.

5.4 laser quantum piece (nano block) is meant by receiving a block laser nano material that constitutes.The adjacent distance of receiving between the grain that the laser quantum piece has three-dimensional large scale direction is in nanoscale, is also referred to as the three-dimensional manometer laser material.It has the energy level of the discrete number of three-dimensional linear independence.

The main synthetic method of laser quantum piece: certain high-purity laser material is melted in containing the fusion crucible that draws preface equipment of smelting furnace, (its clamper is installed several parallel independent seed preface pieces simultaneously by the mechanical device that hauls this kind material seed preface piece, and can control these seed preface pieces independently very lentamente along rotation counterclockwise), under certain high temperature, will immerse the seed preface piece pull-up in the fused solution of this kind high-purity laser material very lentamente; At first contact the fusion laser material on the seed preface piece, will and receive face angle and born of the same parents' the lattice shape etc. received received according to the face of receiving of this seed preface piece and at first be formed with this material preface material that rule, long-range order are arranged; Then along with the rotation and the formation laser quantum piece separately rallentando that moves up.

The fusing point of laser quantum piece obviously reduces.Be generally 670 ° as silver point, and the nanometer silver point can be lower than 100 ℃; The electrocondution slurry made from nano-silver powder can carry out low-temperature sintering.The substrate of nanometer laser device can substitute refractory ceramics etc. with silica-based or nano composite plastics like this.

The laser quantum piece is compared with existing monocrystal, has significant excellent characteristic, is the good nano material of making the nanometer laser device.One of important materials of the laser quantum element of its especially integrated and complanation sensitivity; It also is the main material of multifunctional nano laser sensor.

6. have at least each adjacent cluster distance of one dimension large scale direction all to belong to the interior preface material of nanoscale, be called cluster preface material.

Cluster (receiving a little) does not have periodically or the nano material of random combination in spatial arrangements, is called the non-preface material of cluster.

Have at least each adjacent cluster distance of one dimension large scale direction all to belong to the interior laser preface material of nanoscale, be called cluster laser preface material.

Cluster (receiving a little) does not have periodically or the laser nano material of random combination in spatial arrangements, is called the non-preface material of cluster laser.

By the nano material that many small scale space cluster laser preface materials of irregularly arranging are formed, be called cluster laser and mix the preface material.

The fundamental difference of cluster crystal and cluster preface material is: have the various cracks or the defective of micron number magnitude yardstick in the crystal structure, and these defectives make this crystal not exist the distance of the adjacent atom in range scale bunch of its each linear independence direction that has all less than 100 nanometers.

Cluster be different from receive the grain feature be: the atomicity in the cluster is the integer of fixing, and is called magic number; Generally receive the grain a no magic number notion.

The physicochemical properties of cluster change along with the atomicity that is contained.It has many unusual characteristics, makes them have the conductivity of the quantum effect of high physical and chemical activity, light, physical dimension effect that electricity is led, dopant and superconductivity etc. as great specific area.

The magic number structure of cluster makes it be different from the single atom or the molecule of material.Distance is the structure of nanometer scale between the adjacent atom bunch, makes cluster preface material be different from the monocrystal of solid or liquid again.It is not mysterious material " the 5th attitude ", just special solid or the liquid of structure.

The preparation method of cluster laser preface material: graphite arc method etc.It can generate cluster laser preface material and carbon nano-tube laser preface material etc.

Cluster typical case representative is Fe _n, Cu _nS _m, C _nH _m(n and m are integers) and carbon bunch (C ₂₀, C ₃₆, C ₅₀, C ₆₀, C ₇₀, C ₈₀With fullerene etc.).Cluster can be divided into monobasic elementide, binary elementide, polynary elementide and cluster compound.

Cluster is between single atom and solid-state atom set body.Their atomic arrangement structure and electron motion both be different from molecule, also were different from solid.The cluster material is with the loose cluster of weak power combination and periodically very strong monocrystal (or preface material) or polycrystal (or mixed preface material).

Carbon nano-tube preface material can be divided into Single Walled Carbon Nanotube, double-walled carbon nano-tube and multi-walled carbon nano-tubes preface material.

Carbon nano-tube preface material electricity is relevant with its geometry with performances such as optics, as diameter and helical angle.

Carbon nano-tube laser preface material has conductor or semiconductor excellent properties; Synthetic method: graphite arc method, laser evaporation method and catalystic pyrolysis etc.

Carbon nano-tube laser preface material is as the 1-dimention nano laser material, and light weight, Stability Analysis of Structures have the characteristic of mechanics, electricity and the chemistry of many excellences.It will be used for nanoelectronic element, material obsorbing radar waves etc.By chemical method carbon nano-tube is modified processing, can improve its intensity and conduction, optics and magnetic performance, make it become light-guide material, nonlinear optical material, soft magnetic material, molecular vehicle etc.

Active material is implanted in the carbon nano-tube preface material, made it become biology sensor, can be used for detecting difficult and complicated illness, and be used for the medicine compound probability.

7. by disperseing or complex method is received grain with heterogeneous phase (decentralized photo) and evenly mixed the material that crystal substrate is formed, be called nano composite material.

Decentralized photo is received grain and is evenly distributed among the crystal grain in the crystal substrate or between the crystal grain; Both Direct Bonding even formation coherence structure.

The laser nano composite material is to be uniformly distributed in laser composite material in the crystalline state matrix by decentralized photo (be also referred to as strengthen body) to receive the form of grain.Strengthen body and can be nano material (comprise receive grain, preface tablet, preface material palpus, preface material fiber etc.).Its basic manufacture method is that nano particle is evenly dispersed in the crystal, and makes these particles enter formation structure " interior crystal formation " (being divided into intracrystalline type, crystal boundary type, intracrystalline crystal boundary mixed type) in the crystal.

The most basic technology of preparing of laser nano composite material: highly purified matrix and fusing point be placed in the fusion crucible that draws preface equipment melt (temperature than the fusing point height of matrix, but lower) than the high decentralized photo quantum powder of matrix or the grain ratio as required of receiving and stir than the fusing point that strengthens body; When the temperature of this liquation drops to the fusing point (or hanging down a bit a little) of matrix, under the environment that keeps this temperature,, very lentamente along rotation counterclockwise the seed crystal in the liquation of this kind of immersion material is pulled upwardly by the mechanical device (for example clamper) that hauls this kind composite material seed crystal (can be seed crystal bar, seed wafer or seed crystal piece); At first the melted material that contacts on the seed crystal will at first be formed with the crystal of rule, long-range order arrangement according to the crystal face of this seed crystal and the lattice shape of interfacial angle and structure cell etc.; Form the nano composite material ingot then rallentando along with being pulled upwardly.

Nanometer laser material preparation method commonly used can be divided into solid phase method, liquid phase method and vapor phase method etc. by technical process mesostroma state.Can prepare various metal dust, oxidate nano laser preface material powder and non-oxidized substance nanometer laser powders such as carbide, nitride by these methods with nanoscale.Mechanical mixture dispersion-moulding-sintering process, liquid phase dispersion-moulding-sintering process, original position generation-moulding-sintering process etc. are arranged in addition.

8. by disperseing or complex method is received grain with heterogeneous phase (decentralized photo) and evenly mixed the substrate composed material of preface material, be called composite nano materials.

Decentralized photo is received grain and is evenly distributed on receiving among the grain or receiving between the grain of preface material matrix; Both Direct Bonding even formation coherence structure.

The laser composite nano materials is to be uniformly distributed in laser composite material in the preface material matrix by decentralized photo (be also referred to as strengthen body) to receive the form of grain.Strengthen body and can be nano material (comprise receive grain, preface tablet, preface material palpus, preface material fiber etc.).Its basic manufacture method is to make decentralized photo receive grain to be evenly dispersed in the preface material matrix, makes to receive grain and enter and form structure " interior preface type " (be divided in the preface in type, preface circle type, the preface preface circle mixed type) in the preface material.

The most basic technology of preparing of composite nano materials: highly purified matrix and fusing point be placed in the fusion crucible that draws preface equipment melt (temperature than the fusing point height of matrix, but lower) than the high decentralized photo quantum powder of matrix or the grain ratio as required of receiving and stir than the fusing point that strengthens body; When the temperature of this liquation drops to the fusing point (or hanging down a bit a little) of matrix, under the environment that keeps this temperature,, very lentamente along rotation counterclockwise the seed preface in the liquation of this kind of immersion material is pulled upwardly by the mechanical device (for example clamper) that hauls this kind composite material seed preface (can be seed preface bar, seed preface sheet or seed preface piece); At first the melted material that contacts on the seed preface will at first be formed with the preface material of rule, long-range order arrangement according to the preface face of this seed preface and preface face angle and preface born of the same parents' preface lattice shape etc.; Form the composite nano materials ingot then rallentando along with being pulled upwardly.

The preparation method of laser composite nano materials commonly used can be divided into solid phase method, liquid phase method and vapor phase method etc. by technical process mesostroma state.Sintering method commonly used has pressureless sintering, hot pressed sintering, ultra-high pressure sintering, HIP sintering, microwave sintering, ultra-high pressure sintering, selective laser sintering, discharge plasma sintering, sintering-forging and pressing, reaction-sintered etc.; Also have straight forming-sintering process and surface modification-moulding-sintering process etc.

The synthetic method of laser composite nano materials also has: ion injection, vacuum vapor deposition method, sputtering method, plasma-deposited and sol-gal process etc.

9. the non-linear basic structure of nanometer laser device is the nano tunnel PN junction.It can constitute the nanometer laser diode, utilizes its quantum effect, can realize the existing irrealizable function of semiconductor die body diode.It is made up of PN junction and two electrodes.It launches monochromatic light; And stimulated radiation is greater than spontaneous radiation.The heavily doped GaAs-PN knot of its general employing; The counter-rotating that can realize near the non equilibrium carrier of semiconductor PN distributes.

The nanometer laser diode not only has electrology characteristic, also has optical signature.The tunnel junction and the quantum tunneling effect of doping preface material silicon are the elementary cell and the function of nanometer laser device.Its important parameter is tunnelling speed and threshold voltage.Tunnel junction resistance R _T＞＞coulomb blockade resistance R _K≈ 26k Ω.

The operation principle of preface material device and characteristic and existing quartz crystal device have fundamental difference.Laser preface material preparation of devices method:

But the high-purity silicon rod draws the fusion crucible in the preface instrument to melt in bavin Laski formula,, at a certain temperature very lentamente along rotation counterclockwise the seed preface silicon that immerses in the molten silicon is pulled upwardly by the mechanical device that hauls seed preface silicon (for example seed preface silicon clamper); At first contact molten silicon on the seed preface silicon and receive lattice and receive face angle etc. and at first be formed with the preface material silicon that rule, long-range order are arranged according to this seed preface silicon; Form preface material silicon ingot then gradually.

When preface material silicon growth, if in molten silicon, mix boron impurities (or phosphorus) atom, just can obtain P type (or N type) laser preface material silicon ingot, through steps such as cutting, grinding, polishings, obtain polishing preface material silicon chip.With this silicon chip is substrate, just can make the nanometer laser device on it.

The many laser preface material silicon diodes of quantity will be made on the nanometer epitaxial wafer.The nanometer extension is a kind of technology of taking chemical reaction method to carry out the growth of preface material.Under certain condition, with the preface material silicon chip (or preface material silicon silk) of substrate as the seed preface, allow atom (as silicon atom) be arranged in gradually on this substrate according to the structure of this seed preface regularly, form one deck and have certain conduction type, resistivity, thickness and the complete preface material layer of receiving lattice structure.But epitaxial growth temperature draws the temperature of molten silicon in the preface instrument much lower than bavin Laski formula.The fusing point that epitaxial growth temperature is lower than silicon is about 30%-50%.

The reduction chemical reaction that silicon compound carried out, the free state silicon atom character of generation is very active, at high temperature has a large amount of heat energy.When it falls silicon atom with substrate preface material surface and clashes into, heat energy is emitted, and row is in its surface successively according to the rule of the atomic arrangement of substrate preface material silicon.The free state silicon atom deposits continuously, fitly forms preface material silicon epitaxy layer according to the structure of seed preface silicon.

Growth technology also can adopt chemical vapor deposition (CVD) and molecular beam epitaxy (Molecular Beam Epitaxy, MBE) method.

10. the nanometer laser technology is the product that modern science (quantum mechanics, mesoscopic physics and nanomaterial science) and modern technologies (laser technology, nanometer technology, computer technology and technique of scan tunnel microscope etc.) combine.The nanometer laser device is compared with existing crystal laser, has more superior performance, can be very low as threshold current density, or even by the caused quantum effect electric current of several electrons; Conversion efficiency height between electric energy and the luminous energy; Power output is big etc.Because the preface material has small-size effect, skin effect and quantum effect etc.; Charge carrier very easily forms population inversion in the preface material; Make nano laser export higher power than existing laser.The nanometer laser device has very little threshold current and current density simultaneously, makes device operation current drop to minimum, can guarantee device continuous operation at room temperature.

Nano laser is that the high-power nanometer LD with specific wavelength that made by the preface material or LD array excite specific laser preface material and produce the device of specific wavelength.Nano laser is replaced the technology of existing corresponding laser, is exactly the nanometer laser technology.

As long as behind the nano laser of preface material, the laser of soon making based on crystal replaces with the nano laser of making based on the preface material with the crystal laser technique extension.Then nano laser just can be applied to existing applied all fields of laser and scope etc. equally; For example space nanometer laser communication (Free Space Nano Optics, FSNO), the three-dimensional quick shaping of nanometer laser, biological manufacturings of nanometer laser, nanometer laser quick shaping, nanometer laser radio communication, nanometer laser shows, nanometer laser draws thunder and dispersing fog, nanometer laser range finding, nanometer laser radar, nanometer laser guidance and navigation, nanometer laser are processed (Nano Lasser beam machining), nanometer laser nuclear fusion, nanometer laser various aspects such as electrooptical countermeasures.Simultaneously nanometer laser also in military affairs, in the medical science, in the energy, in the traffic, in the information, the medium various aspects of communication neutralization materials play a great role.Nanometer laser has fabulous application prospect as media of information at aspects such as optical communication, optical information processing and storage, robot vision.

Nanometer laser is the carrier of transmission information; The parameters such as amplitude, intensity, frequency, phase place and polarization that change laser make it the technology of the information of carrying, and will replace existing technology in optical communication, optical information processing, photoelectron war, photochemical therapy, light quick shaping, navigation, measurement and control etc.

Nanometer laser communication needs only technique extensions such as the wave division multiplexing WDM of microwave section and time division multiplexing tdms after the nanometer laser technology, just can enlarge communication band.Its transmission means has Optical Fiber Transmission and directly transmits two kinds.Directly transmission be meant nanometer laser in atmosphere, water or in the outer space not by the transmission of other media.Its emission system is the nano laser of an emission of lasering beam, modulator with signal loading on light wave and a transmitter-telescope convergent pencil of rays concentrated in the very little solid angle transmit to the destination.Its receiving system is passed to the convergent pencil of rays that receives photelectric receiver and light signal is become the signal of telecommunication by a receiving telescope, by demodulator the signal of telecommunication is restored (Figure 10) at last.

The nano photoelectric countermeasure techniques comes down to replace existing crystal laser with nano laser.Utilize the nanometer laser facility to scout and counterreconnaissance, enemy's photoelectronic reconnaissance equipment is disoriented, guided weapon is out of control, and the usefulness of communication, commander, control system interruption and laser weapon is malfunctioning; The optoelectronic device of guaranteeing one's own side simultaneously is normal.The nano photoelectric counterweapon is a kind of precision strike enemy's a novel advanced weaponry.

Description of drawings

Fig. 1 scanning tunnel microscope schematic diagram.It is used for detecting microscopic appearance and processing; Has high spatial resolving power; Main composition: the superfine probe in top, be used for three piezoelectric ceramic of 3-D scanning and be used to scan and the controller of current feedback etc.

Fig. 2 metastable state E ₂With ground state E ₁Between the population inversion schematic diagram.Pumping source is with ground state E ₁On electronic pumping to excitation state E ₃On, electronics will be transferred to metastable state E very soon ₂On, cause the population N on the metastable state ₂Greater than ground state E ₁On population N ₁Realized metastable state E ₂(energy is higher) and ground state E ₁The counter-rotating of population between (energy is minimum).

Fig. 3 excitation state E ₁With metastable state E ₂Between the population inversion schematic diagram.If the ground state level of metastable state material is E ₀The following energy level E of population inversion ₁(E ₁＞E ₀) not in ground state, and in excitation state.Because following energy level E ₁Particle originally seldom, as long as metastable state E ₂On particle accumulation is arranged slightly, just can realize excitation state E ₁With metastable state E ₂Between population inversion.

Fig. 4 dye molecule energy level schematic diagram.After ground state had absorbed external photon, molecule just transitted to higher S from ground state level ₁On the attitude energy level (A among the figure → b).Molecule also might be from the ground state transition to S ₂Attitude is fallen S more soon ₁On the attitude.Because frequent energy exchange.The molecule that great majority are excited decay to S radiationlessly ₁On the lowest energy level of attitude (b among the figure → B).Excitation state S like this ₁With ground state S ₀Between just realized population inversion.

Fig. 5 dyestuff nano laser schematic diagram.The light beam of the adjustable dye nano laser of nanometer laser pumping and resonant cavity axle form a low-angle (about 3 °).Resonant cavity is made up of reflecting grating G and a mirror M that is coated with sodium rice deielectric-coating.Rotating shutter just can change the frequency of output laser.When not inserting a Fabry-Perot (F-P) etalon in the resonant cavity, the live width of output laser is 0.05 nanometer.

Fig. 6 electroluminescence nanometer laser device schematic diagram.When it adds forward voltage; Non equilibrium carrier is surperficial certainly to diffusion inside.When they spread to PN junction, form photon after two reflectings surface repeatedly come and go, outwards export laser.

The schematic cross-section of the double-deck optical fiber nano laser of Fig. 7.Double-layer nanometer optical fiber has increased an inner cladding (the inner cladding shape can be circle) than individual layer nano optical fibers, and the lateral dimension of inner cladding and numerical aperture are all much larger than fibre core.

The coefficient of expansion schematic diagram of Fig. 8 preface material and non-preface material.Solid-state receive the grain Mi Dui close, active force is bigger, the preface material coefficient of expansion is littler than its liquid usually.When temperature T is equal to or slightly lower than fusing point T _mThe time, discontinuous variation (B → C), separate out the preface material appears in the liquation volume.If the material temperature is less than T _mIt is little of presenting solid-state warm T that decline sequential material is not separated out ， Shrink _g(during B → E), its coefficient of expansion sudden change; At T＜T _gThe time, form non-preface material.

Fig. 9 receives graph of a relation between the equivalent radius of grain and the total variation of system's free energy.When receiving an equivalent radius r＜critical preface nuclear radius R _KThe time, the instantaneous formation of preface embryo, instantaneous again disappearance.As r＞R _KThe time, the preface embryo can spontaneously be grown up into preface material stable and that have certain certain size in liquation.It can not disappear again.Work as r=R _KThe time, the preface embryo both may disappear, and also may grow up into stable small size preface material.

Figure 10 laser space communication system schematic diagram.Its emission system is the nano laser of an emission of lasering beam, modulator with signal loading on light wave and a transmitter-telescope convergent pencil of rays concentrated in the very little solid angle transmit to the destination.Its receiving system is passed to the convergent pencil of rays that receives photelectric receiver and light signal is become the signal of telecommunication by a receiving telescope, by demodulator the signal of telecommunication is restored at last.

Figure 11 heavy doping GaAsPN nanometer laser diode schematic diagram.It is that heavily doped P-GaAs preface material and N-GaAs preface material are closely linked, and forms a P ⁺N ⁺Knot and built-in field.Under the forward bias effect, charge carrier injects and forward current occurs.

Figure 12 single heterojunction GaAs semiconductor nano laser schematic diagram.It is by semiconductor preface material N-GaAs and semiconductor preface material P ⁺-Al _xGa _1-xClamp closely about As that semiconductor preface material P-GaAs forms.General 50 nanometer to 500 nanometers of P district thickness, laser produces in the P district, and threshold current is low.

Figure 13 double heterojunction GaAs semiconductor nano laser schematic diagram.It is with semiconductor preface material N-GaAs and N ⁺-Al _xGa _1-xAs and semiconductor preface material P-GaAs and P ⁺-Al _xGa _1-xN among the As ⁺-Al _xGa _1-xAs and P-GaAs combine closely and constitute.Threshold current is very low.

The position that embodiment microscopic particles (comprising atom, electronics, molecule etc.) appears in the space is a kind of probability that depends on its matter wave.This probability is the function of this wavelength amplitude.Object depends on its material wavelength amplitude and appears at the probability of certain locus, is called the several of this object and heads a delegation.The wavelength that object was had that quality is m, move with pseudo-velocity v is h/ (mv); Wherein h is a Planck's constant.The power rail road of each electronics has definite energy in the atom.It is the electron probability group that follows circumnuclear each energy track of atom that electronics wherein moves.The photon frequency of atomic emissions is corresponding to circumnuclear each energy track of atom.This phenomenon is called the duality of the fluctuation-particle of object.

Adjacent atom overlaps than the external electrical shell in the nano material (it is preface material, mixed preface material or non-preface material); Electronics is confined on some atoms no longer fully, and it can be from an atom transfer to adjacent other atom.Therefore, the valence electron in the outside shell of atom can move in whole nano material.This communization that is referred to as electronics that moves moves.When having only electronics on the identical corresponding shell of energy to overlap mutually in each atom, electronics could shift between these shells, causes that communization correspondingly moves.Preface material and crystal, mix preface material and polycrystal, non-preface material with noncrystal between essential distinction exactly: have in the large scale scope of one dimension direction the duality of movement of electrons demonstration fluctuation-particle at least in the preface material (or mixed preface material, non-preface material); And electronic motion can be regarded as pure particle in the crystal (or polycrystal, noncrystal).

Electronics is excited to from the filled band (outermost shell) that has been full of valence electron and leads after the Bands, and then the hole appears in this filled band.The electric charge that it is equal to a Bands+e moves; And cause the communization in hole.Obviously the mobile of these electronics (hole) is other electronics of inside shell (hole) that are different from the atom in the preface material.The electronics of these outside shells (hole) communization is that electronics is transferred to another corresponding shell by a shell.

When electronics each atomic time of process, because communization, moving of it still approaches the movement law on the outside shell of atom originally.Therefore the communization electronics also can keep their some features in atom in the preface material (or mixed preface material, or non-preface material).In addition, free electron can move in whole space, and the communization electronics of preface material also can move in whole nano material; Therefore communization electronics basic characteristics also have similarity with free electron.Certainly, the communization electronics is subjected to periodically potential field effect of atom in the nano material (preface material, mixed preface material or non-preface material), still is different with free electron.Because the structure that the periodicity of long-range order repeats in the preface material; The preface material has its general character in each, for example uniformity, anisotropy, symmetry and fixing fusing point etc.Various preface equipment structure diversity and composition ever-changing determined the various concrete properties of this preface material.

In the preface material receive the grain (comprising molecule, atom or ion etc.) the surface have electric charge; Its arrangement in the space is array format rule, periodic, on the one hand owing to have electromagnetic interaction between two adjacent atoms of receiving in the grain; On the other hand since two adjacent receive grain around several " quantum bonding actions " of heading a delegation of existing.Different quantum bond energys causes receiving grain and does different arrangements in the space, produces the preface material with different structure.

1. in the solid nano laser, to make bar-shapedly usually as the preface material (or mixed preface material or non-preface material) of matrix, both ends of the surface are polished to optical flat, and have the good depth of parallelism.Plate the reflection nanometer film in these both ends of the surface, just constitute optical resonator.The ruby nano laser is by the Cr that is mixed with ten thousand/(by mass) ₂O ₃Artificial white stone (Al ₂O ₃) preface material rod makes; Al in the preface material ³⁺By Cr ³⁺Replace; Active ions are Cr ³⁺Ion.Show fluctuation-particle duality at excellent direction of principal axis electronics.The solid nano laser generally adopts xenon lamp or high-pressure mercury-vapor lamp as pumping source.But light source can also be used semiconductor light sources in addition, for example semiconductor light-emitting-diode (LED) and semiconductor laser diode (LD) etc.; Perhaps fiber laser light sources such as (LASER).

When the ruby nano laser turns round, Cr ³⁺Absorbed outside photon and from ground state ⁴A transits to excitation state ⁴T ₁Or ⁴T ₂This is corresponding to Cr in the ruby ³⁺The royal purple district of the absorption spectrum of ion and the absworption peak of Green Zone. ⁴T ₁Or ⁴T ₂Two energy levels are very wide, and each width is about 100 nanometers, make that the efficient of optical pumping pumping is very high.Cr ³⁺On these two energy levels is unsettled, transits to metastable state rapidly radiationlessly ²On the E; And E ²Life-span reach 3 * 10 ^-3S; So at E ²Last energy accumulate a large amount of Cr ³⁺Ion exists like this ²E and ground state ⁴Population inversion appears between the A.

Ruby is received the energy level of light device ²E by two lean on very near energy level

With

Form.From

Transition to ground state claims ₁Transition is corresponding to 0.6943 micron of wavelength; From

Transition to ground state is called R ₂Transition is corresponding to 0.6929 micron of wavelength.Because

With

Two energy levels lean on very closely, and warm-up movement makes the exchange of particles of this two energy inter-stage very frequent, can think that their population equates all the time.But because R ₁Line and R ₂The fluorescence intensity ratio of line is 7: 5; R as a result ₁Line at first reaches threshold values, and produces laser.At this moment Particle on the energy level is consumed in a large number,

On particle add to rapidly

Come on the energy level, make R ₂Line does not reach threshold values all the time.So in the ruby nano laser, have only R ₁Transition energy forms nanometer laser.

The solid nano laser generally has two kinds of typical structures.A kind of is the inside that the nanometer laser rod is placed on helical form lamp source, two circular end surface plating reflectance coatings (or nanometer reflective film) of this rod.Another kind is that the nanometer laser rod is placed on the focal line of elliptic cylinder mirror, and the wire el lamp source of using as optical pumping is placed on another focal line; Because these two focal lines are optical conjugates to elliptic cylinder; So this device has improved pumping efficiency greatly; Scribble the nanometer reflecting surface thin layer on two speculums of resonant cavity, and these two speculums are to separate assembling with the nanometer laser rod.

Adopt semiconductor diode (LD) to replace the solid nano laser of common light source pumping, thickness by changing the LD active area or change active area " component " and control by temperature, can accurately control the optical wavelength of LD output, realize that the spectrum of pumping and absorption is complementary.Replace the solid nano laser of general light source pumping with LD, by compact, firmly, can form by modular solid components.Its pumping efficiency is very high, so laser works time heating is little, does not need existing solid state laser because thermal effect and the cooling system that must be equipped with.

2. the operation material of dye cell is a nano dye solution in the dyestuff nano laser (Fig. 5).This nano dye solution is the non-preface material of a kind of liquid state.Nano dye molecular entergy level T ₁And T ₂(Fig. 4) be triplet.Though they directly are not involved in laser transition, and the dyestuff nano laser is had significant effects.From singlet state S ₁To triplet T ₁Though transition be that selection principle institute is unallowed, the quantum effect of nano dye, this transition also has certain probability to take place.Because T ₁To S ₀Transition forbid, so T ₁Molecule on the attitude is cumulative.From T ₁To T ₂Transition allow, and the frequency range of the photon that this transition absorbed is just identical with the frequency range of laser transition.Work as T ₁After having accumulated enough molecules on the attitude, T ₁To T ₂Absorption the gain of nano laser will be descended so that nanometer laser cancellation.For this reason, some dyestuff nano lasers pulse running often; Pulse duration is shorter than T ₁Particle integration time on the attitude.

It in the dyestuff nano laser (Fig. 5) light path with the adjustable dye nanometer laser of nanometer laser source pumping.The excitation source of dyestuff nano laser is the solid nano laser, as cresol-purple nano laser, ruby nano laser etc.

3. the semiconductor nano laser is by nanometer P in the semiconductor preface material ⁺N ⁺Structure becomes.In the semiconductor preface material GaAs of pure III family-V compounds of group, mix few flow control 2 family's element zinc (Zn) atoms replacement part Ga atom wherein, just form the P-GaAs semiconductor nano material.Mix few flow control 6 family's elemental tellurium (Te) atoms replacement part A s atom wherein among the preface material GaAs, just form the N-GaAs semiconductor nano material.

3.1 the nanometer laser diode is also formed (Fig. 6) by PN junction and two electrodes.Its structure is basic the same with laser diode (LD).The nanometer laser diode is to be made of the semiconductor preface material that mixes; And LD is made of the semiconductor crystal that mixes.This is essential distinction between them.

The nanometer laser diode is that heavily doped P-GaAs preface material and N-GaAs preface material are closely linked, and forms a P ⁺N ⁺Knot and built-in field (Figure 11).Under the forward bias effect, charge carrier injects and forward current occurs.Nanometer laser diode resonant cavity can utilize and P ⁺N ⁺The orthogonal preface material of junction plane cleavage surface (110 face) constitutes Fabry Perot resonator.The cleavage surface of one end (110) plates the high-performance reflectance coating, and the cleavage surface of the other end (110) is as speculum and output; The concussion of realization nanometer laser.

High power nanometer laser diode array SLS RPT system is after several nanometer laser diodes are coupled by optical fiber (can be solid core fibres or hollow optic fibre), fiber-optic output critically is arranged in array, in this array back microlens array is set, each unit of this lens arra aims at each fiber-optic output, and the light beam that each laser diode is sent forms length and is about 200 microns short-term on the working face of the place ahead of fiber array.If short-term length is less than the centre-to-centre spacing between optical fiber, then the light of Xing Chenging is interrupted dotted line, only needs the mutual Inlaid embedding of the virtual image with some arrays formation, makes it to form solid line.High power nanometer laser diode array SLS RPT system is the technical foundation of desktop type SLSRP system.

High power nanometer laser diode array is one of core component of whole system.It can have following several version:

3.1.1 discrete type high power nanometer laser array is to form array with a plurality of special heat sink high power nano lasers of Bands by accurate assembling art, and each light-emitting area is arranged in line.

3.1.2 single-chip array high power nano laser is to process several nanometer laser units at interval in accordance with regulations on same preface material chip, makes the light-emitting area alinement of each laser unit.

3.1.3 optical-fiber type high power nano laser array, be by optical fiber of each high power nano laser coupling, because optical fiber can be crooked, therefore nano laser does not need to be closely aligned to be in line, can use general high power nano laser, after the optical fiber coupling, fiber-optic output closely is arranged in array.

3.2 the active area of heterojunction semiconductor nano laser is not P ⁺N ⁺The interface; But at P ⁺The district.Its structure is divided into single heterojunction and double heterojunction.

3.2.1 single heterojunction GaAs semiconductor nano laser is by semiconductor preface material N-GaAs and semiconductor preface material P ⁺-Al _xGa _1-xClosely clamp (Figure 12) that semiconductor preface material P-GaAs forms about As.Wherein N-GaAs and P-GaAs form PN junction; P-GaAs and P ⁺-Al _xGa _1-xAs forms PP ⁺Knot.Electrons spread arrives PP ⁺The district is blocked because of potential barrier is high, stays the P district; The hole diffusion arrives PP ⁺The district arrives the P district because of potential barrier is not high; Thereby in the formation population inversion of P district.P district thickness is generally 50 nanometer to 1000 nanometers, and laser produces in the P district, and threshold current is low.

3.2.2 double heterojunction GaAs semiconductor nano laser is with semiconductor preface material N-GaAs and N ⁺-Al _xGa _1-xAs and semiconductor preface material P-GaAs and P ⁺-Al _xGa _1-xN among the As ⁺-Al _xGa _1-xAs and P-GaAs combine closely and constitute (Figure 13).Electrons spread arrives PP ⁺The district is blocked because of potential barrier is high, stays the P district; The hole diffusion arrives N ⁺The P district also is blocked because of potential barrier is high, stays the P district; Thereby very easily form population inversion in the P district.P district thickness is generally 5 nanometer to 50 nanometers, and laser produces in very narrow P district, and threshold current is lower.

4. optical fiber nano laser (Fig. 7) is as laser medium with nano optical fibers itself; Its resonant cavity coheres the chamber sheet by two end faces of nano optical fibers or plates that nano thin-film constitutes.Its cavity body structure is simple, and the nano optical fibers softness can be coiled into arbitrary shape in minimum profile curvature radius scope outside sweep.Small and exquisite modular high-power semiconductor laser of volume that its selection emission wavelength and nano optical fibers absorption characteristic are complementary or semiconductor nano laser are as pumping source; Be easy to realize high efficiency and high power.

The very simple and economical optical element of optical fiber nano laser utilization just can focus on the light beam of optical fiber nano laser output diameter less than 10 microns hot spot.Because it has the good focusing characteristic, so can obtain good machining accuracy and quality in industrial processes.

The optical fiber nano laser adopts fiber-coupled diode pumping and leptosomatic fiber resonance cavity, utilizes with the heat conduction of ambient atmosphere and cools off, and just can make the laser operate as normal.Its output wavelength changes with temperature and drive current; By controlling this two parameters, can improve absorption efficiency.

The energy conversion efficiency height of optical fiber nano laser.It is by module combinations, and power output can reach several kilowatts of orders of magnitude, and it is enough that most of material is processed.And, can obtain green glow even ultraviolet ray by frequency doubling technology, satisfy some and hold different processing needs.

The modulating performance of optical fiber nano laser is good.When the wavelength of nanometer laser was 1.1 microns, modulating speed can reach 50kHz.Its output power stability is good.Therefore the optical fiber nano laser has the stable sintering course of processing.This is that other solid state lasers are incomparable.

5. the nanometer laser material is except basic generation technology and extension generation technique (being divided into chemical vapor deposition techniques and molecular beam epitaxy) technology, also have many other the semiconductor nano laser material and the technology of preparing of preface material or non-preface material.

The physics method mainly contains vacuum condensation method, mechanical ball milling method, sputtering method, liquid metal ion source method, mechanical alloying method, amorphous crystallization method etc.

Chemical method mainly contains the precipitation method, sol-gal process, microemulsion method, solution thermal response method, solution evaporation, solution reduction method, electrochemical process.

5.1 physical preparation method mainly adopts technology such as light, electricity, and material is evaporated in vacuum or inert gas, makes material atom or molecule form the grain of receiving of semiconductor nano laser preface material or non-preface material then, thereby forms the nanometer laser material.Below be several main physical preparation methods:

5.1.1 vacuum condensation method: with methods such as vacuum evaporation, heating, high-frequency inductions, make the vaporization of metal or raw semiconductor or form plasma, quick then or slowly cooling is finally gone up the grain of receiving that forms nanometer laser at condenser pipe (comprising substrate); Receive the size of grain and the distance between the grain received by regulating evaporating temperature field and gas pressure and other parameters, can controlling; And obtain good preface material.Good, even particle size distribution of Zhi Bei preface material purity height, institutional framework and may command in this way, the minimum grain size of grain received can reach 2 nanometers; Be applicable to any transpirable element and compound.

5.1.2 mechanical ball milling method: to pulverize and the nanometer of grinding the method realization material powder that combines.Suitably control the condition of mechanical ball-milling method, can obtain the nano powder of pure element, alloy or composite material.This method operating procedure is simple, with low cost, preparation efficiency is high, can prepare high melting point metal alloy nano powder or laser material nano powder that conventional method is difficult to obtain.But its distribution of particles is inhomogeneous, purity is lower.

5.1.3 ion implantation: certain atoms of elements or molecule are converted to ion in ion implantor intermediate ion source, then these ions up to tens to the electric field of hundreds of kilovolt, be injected into the surface of preface material (semiconductor, alloy, polymer etc.), and enter subsurface certain depth.

5.2 the chemical preparation process and the physical preparation method main distinction are to be accompanied by in the chemical preparation method chemical reaction.Below be main chemical method:

5.2.1 vapour deposition process: utilize the chemical reaction of metallic compound steam to synthesize to receive grain.For example, utilize induced with laser gasification phase deposition technique, can accurately control receive grain particle diameter and receive intergranular apart from etc., prepare high-purity, do not have the grain of receiving of bonding, even particle size distribution.Vapour deposition process can be prepared the non-preface material of laser of a few nanometer to tens nanometers or laser preface material and receive grain, thereby obtains non-preface material of nanometer laser material and preface material.

5.2.2 chemical precipitation method (comprising: methods such as coprecipitation, homogeneous precipitation method, the polyalcohol precipitation method, precipitation transformation method and direct conversion method): precipitation reagent is joined in the soluble-salt solution that comprises one or more ions, make solution generation hydrolysis, form insoluble hydroxide, hydrous oxide or salt and from solution, separate out; Then with original anion flush away among solvent and the solution; Through thermal decomposition or processed, just can obtain the powder body material of nanoscale.This method technology is simple, is fit to preparation nanometer laser oxide powder material; But purity is lower.

5.2.3 hydrothermal synthesis method (pyrohydrolytic method): synthetic in fluids such as the aqueous solution or steam earlier under the condition of HTHP during preparation nanometer laser preface material, again through separating and heat treatment obtains to receive grain.Its advantage is the purity height, and granularity is controlled easily.Can prepare the laser preface material that particle diameter has only several nanometers with hydrothermal synthesis method.

5.2.4 sol-gal process: its basic principle is: metal alkoxide or inorganic salts form colloidal sol through after the hydrolysis, solute polymeric gelization then, remove contained organic principle through Low Temperature Heat Treatment such as gel drying, roastings again, finally obtain the grain of receiving of inorganic material.The preparation process of this nanometer laser material is controlled easily, receives grain evenly, is suitable for preparing the grain of receiving of inorganic preface material.

6. the preparation method of cluster preface material and carbon nano-tube preface material etc.: preface material basic generation technology.It can generate carbon nano-tube laser preface material.

Cluster C ₆₀The graphite arc method: at the indoor high temperature helium that is filled with the about 13.3kPa of pressure of vacuum reaction, adopt thicker graphite rod as negative electrode, thinner graphite rod is as anode.When between two graphite electrode rods, being connected to direct voltage,, be settled out cyclic products on the graphite cathode, be settled out the dust-like product, wherein all contain C at reaction chamber wall at this indoor generation arc discharge ₆₀The black flue dust; The cigarette ash of carbon slowly cools off under valve and instrument control; The carbon atom that aggregates into synusia that inert gas He discharges carbon arc keeps the long period near electric arc, and the carbon atom in the carbon-coating sheet seals automatically gradually and forms C ₆₀C ₆₀Purification process be to purify earlier cigarette ash, remove hydrocarbon with the ether washing again.C ₆₀Method for concentrating is to add an amount of distilled water in feeding solution benzene, removes amorphous carbon and insoluble matter, slowly heating again, and dry back obtains purer C ₆₀The preface material.The distilled water of an amount of volume ratio does not influence C ₆₀Directionality; Reduce the growth rate of cluster, can make the less C of defective ₆₀

The catalystic pyrolysis of synthesizing carbon nanotubes: its basic principle is that organic carbon source decomposites active carbon atom bunch under high temperature action, under catalyst is received the effect of grain, rearranges the formation carbon nano-tube in certain environment and atmosphere.Therefore, receive parameters such as the size of grain and kind, reaction temperature, atmosphere by kind, the catalyst of regulating carbon source, the type of adjustable carbon nano-tube, structure, form and arrangement.

C ₆₀Through measuring energy gap is 1.7eV, is a kind of nanometer laser material.At C ₆₀Can be made into extrinsic semiconductor nanometer laser material (comprising preface material or non-preface material) after mixing boron or phosphorus in the preface material.

Carbon nano-tube is mixed the cross section of preface material and is made up of two or more coaxitrons; Distance is about 0.34 nanometer between the adjacent two layers tube wall.The tube that this tubular structure is made up of the hexagonal mesh that is similar to graphite.The general closed at both ends of carbon nano-tube, diameter is between zero point a few nanometer to tens nanometers, and length can reach several microns to tens microns.C wherein ₆₀Fullerene can be made into laser preface material pipe.

7. other manufacture methods of laser nano composite material are to make to receive grain and be evenly dispersed in the host material, and make these receive grain to enter and form structure " interior crystal formation " (being divided into intracrystalline type, crystal boundary type, intracrystalline crystal boundary mixed type) in the matrix.The main process of wherein liquid phase dispersion-moulding-sintering process is that nanometer powder is scattered in the solution that contains matrix components, by the adjusting process parameter, make under the situation that does not have crystallization, reunion, sedimentation that system is freezed, gel, obtain composite powder through heat treatment.Zhi Bei nano composite material in this way, its microstructure is more accurate, and performance is better.

Generated in-situ principle is to select suitable reactant (gas phase, liquid phase or solid phase) according to the material designing requirement, under the suitable temperature by the physical-chemical reaction between the preface material matrix; Original position generates the decentralized photo that is evenly distributed.It can overcome the problem that other technologies occur, as overcomes preface material matrix and decentralized photo and soak into badly, and interfacial reaction produces brittle layer, and dispersed phase distribution is inhomogeneous, and small (micron order or nanoscale) difficulty is compound etc.

8. the basic manufacture method of laser composite nano materials is to make decentralized photo receive grain to be evenly dispersed in the preface material matrix, makes to receive grain and enter and form structure " interior preface type " (be divided in the preface in type, preface circle type, the preface preface circle mixed type) in the preface material.

Composite nano materials is except the most basic technology of preparing, and other the most frequently used nanometer laser composite process are composite powder-moulding-sintering processs.It directly produces preface material matrix and the mixed uniformly composite granule of decentralized photo by chemistry, physical process, uses forming and sinterings such as laser synthetic method then.Adopt this method, comprised needed nanophase in the composite granule; And nanophase evenly disperses in composite granule, the problem that does not exist nanophase to disperse and reunite.

An approach that obtains stabilized scattering nano laser slurry is that nanometer laser preface material particle is carried out surface modification, makes these particles reach monodispersed purpose.This method is with the decentralized photo particulate or receives the grain surface by chemistry or physical method parcel one deck oxide or graft polymer chain, thereby the acidity on change micelle surface etc. stop the reunion of particle (particulate or the grain of receiving), improve dispersion effect.It mainly is by precipitation reaction parcel and solution-gel reaction parcel that particle surface is wrapped up modification.

9. the non-linear basic structure of nanometer laser device is the nano tunnel PN junction.The condition of coulomb blockade and electron tunneling appears in quantum current: 1. coulomb blockade can must be greater than the thermal agitation energy, otherwise thermal noise will be above the quantum tunneling process of electronics; The coulomb blockade effect occurs, should reduce the tunnel junction capacitor C.When room temperature (T ≈ 300K), thermal agitation can K _BT=25meV, capacitor C＜3.2aF; Require the area of tunnel junction minimum, reach nanometer scale; 2. the resistance R of tunnel junction ₁And R ₂, all must be greater than quantum resistance, i.e. R ₁(or R ₂)＞h/e ²≈ 26k Ω.

Nanometer laser device tunnel junction adopts preface material silicon chip as substrate; (or more than one a) tunnel junction can be formed by diffusion technology.It is a growth layer of silicon dioxide film on N type preface material silicon chip, utilizes photoetching technique to carve the diffusion window on oxide-film, carries out boron diffusion, forms tunnel junction.

Another kind of preparation tunnel junction method: at the low N of resistivity ⁺On the type preface material silicon chip, earlier, on epitaxial loayer, utilize oxidation, photoetching, diffusion isoplanar process then, carry out acceptor impurity, donor impurity diffusion successively, to obtain the PN tunnel junction with the epitaxy technology higher N type layer of a layer resistivity of growing.

The nano chips technology of preparing of nanometer laser device and integrated circuit all can adopt based on solid state diffusion process, and this technology comprises extension, oxidation, photoetching, diffusion of impurities and metallization.Making a complete nanometer laser device or its integrated circuit need pass through tens procedures such as design, mask manufacturing, nano chips manufacturing, assembling, detection and just can finish.Wherein crucial and core technology is the nano chips technologies of preparing.

Preface material silicon is that compound by silicon is (as SiCl ₄And SiHCl ₃) carry out that chemical reaction decomposes or by carbon in stove to silicon dioxide (silica sand SiO ₂) reduce and obtain.With the latter is example, and the original material of making silicon is with a kind of highly purified silica sand (SiO ₂) and multi-form carbon (as coke, coal) put into boiler tube and heat, then following chemical reaction can take place:

SiC (solid)+SiO ₂(solid) → Si (solid)+SiO (solid)+CO (gas)

Above-mentioned steps can form the silicon of metallurgical grade, and purity is about 98%, with the silica flour of metallurgical grade broken and and hcl reaction, generate trichlorosilane SiHCl ₃

Si (solid)+3HCl (gas) → SiHCl ₃(gas)+H ₂(gas)

Trichlorosilane at room temperature for liquid (boiling point is 30 ℃), can utilize fractionating process with the Impurity removal of not wanting in the liquid, and the trichlorosilane after the purification is made reduction reaction with hydrogen again and generated electronic-grade silicon:

SiHCl ₃(gas)+H ₂(gas) → Si (solid)+3HCl (gas)

The silicon of this electron level is the polycrystalline silicon rod of ultra-high purity.It comprises many different silicon wafer particles; Can be used as the base stock of preparation laser preface material silicon.

But the polysilicon of ultra-high purity is placed on bavin Laski formula draws the preparation of carrying out the preface material in the preface instrument.Fundamental method is a czochralski method, at first makes the polysilicon fusion become liquid state, then a seed preface silicon of doing accurate pointing is immersed in the molten silicon, and rotation seed preface silicon also is pulled upwardly from fused solution simultaneously very lentamente.Molten silicon constantly generates by its preface material form on seed preface silicon like this, just pulls out column laser preface material silicon rod.

But bavin Laski formula draws the preface instrument that three major parts are arranged: 1. stove comprises mechanical device, a heater and a power supply unit of the crucible of a fusion polysilicon (Si), graphite base, a clockwise direction (C) rotation; 2. draw seed preface mechanical device, comprise seed preface clamper and counter clockwise direction (CCW) whirligig; 3. environment is controlled, and comprises supply (as argon gas), flow control and the gas extraction system of gas.In addition, drawing the parameters such as temperature, seed preface diameter, the speed of drawing the seed preface and the speed of rotation of preface equipment all is with micro-processor controlled, and uses the program control processing step.In addition, also have various transducers and feedback loop, The whole control system can automatically be reacted, guarantee the quality of laser preface material silicon ingot.

During laser preface material silicon growth,, just can obtain P type (or N type) preface material if in molten silicon, mix boron impurities (or phosphorus) atom.Laser preface material silicon ingot can be cut into preface material silicon chip with diamond tool, cutting determines 4 preface material silicon chip parameters: surface direction (as＜100〉or＜110), thickness (as the 0.5-0.7 millimeter), gradient (difference of the preface material silicon wafer thickness that passes through) and flexibility (from the center of preface material silicon chip to the degree of crook at edge).Preface material silicon chip after the cutting obtains polishing preface material silicon chip through steps such as grinding, polishings.With polishing preface material silicon chip is substrate, just can make the nano chips of nanometer laser device or its integrated circuit on it.

Also have growth technology to adopt chemical vapor deposition (CVD) and molecular beam epitaxy (Molecular Beam Epitaxy, MBE) method.

9.1CVD method growth preface material silicon epitaxy layer, the method for employing thermal decomposition of silane.It is at high temperature thermal decomposition of silane to be generated that silicon atom is deposited on the preface material silicon substrate and form.Its growing principle is to similar with hydrogen reduction silicon tetrachloride generation free silica; Advantage is that the needed temperature of thermal decomposition of silane is lower, can reduce autodoping and back-diffusion effect etc., prepares highly purified preface material silicon epitaxy layer easily.It carries out in the atmospheric pressure cvd reacting furnace, by increase hydride doping impurity (as diborane, arsine, phosphine etc.) in reacting gas, can obtain P type or N type nanometer laser material.

9.2 molecular beam epitaxy (MBE) is a kind of special vacuum vapor deposition method.This method growth preface material silicon epitaxy layer mainly contains plasma and strengthens (P-MBE) and laser-enhanced (LASER MBE, L-MBE) two kinds.It is under the condition of system held ultra high vacuum and substrate atoms level cleaning, realizes that by the physical deposition of atom, molecule or ion preface material extension generates, and is particularly suitable for the super lattice laser preface material of receiving of growth.

One or more hot atoms (or thermo-molecular) beam evaporation is to the surface of substrate preface material silicon, along the come out quantum preface material film of atom level thickness and evenness of the face of the receiving epitaxial growth of a certain preface material, and this film thickness, component, doping etc. all can accurately be controlled, and are fit to the laser preface material film and the super lattice film of receiving of laser of preparation high-quality.The MBE key in application be nanometer laser preface material and its substrate receive lattice constant and type matching.

MBE can accurately control the stoicheiometry of preface material epitaxial loayer, can accurately control Impurity Distribution again, and preface material underlayer temperature is low also can be had outdiffusion of inhibition solid phase and autodoping.The performance of the ZnO nanometer laser material of its preparation is fine, has good photoelectric characteristic.

The MBE utmost point is the thickness of control growing layer accurately, the monatomic or monolayer of at every turn can only growing; Can prepare quantum dot, quantum wire etc.

10. replace existing crystal laser with nano laser, nanometer laser equipment can be applied in all trades and professions, and the performance significant role.

10.1 in space (wireless) the nanometer laser communication (Figure 10), emission system has the nano laser of emission of lasering beam, to laser, transmitter-telescope concentrates on laser beam in the very little solid angle and transmits to the destination modulator with signal loading; Receiving system passes to demodulator to the laser beam that receives by receiving telescope light signal is become the signal of telecommunication, by amplifier with signal restoring.

Satellite nanometer laser communication system couples together the formation communication network by laser beam with several satellites, is carrier transmission information between satellite and ground with the nanometer laser.Adopt this communication mode, the nanometer laser signal advances along Earth's orbit in the space, just returns ground to the destination signal.

10.2 in the nano photoelectric countermeasure techniques of military affairs, the nanometer laser alarm equipment mainly is made up of nanometer laser receiving system, photoelectric sensor, signal processor, demonstration and alarm device etc.The nanometer laser receiving system is used to intercept and capture behind the most of stray light of enemy's laser beam, filtering the nanometer laser beam convergence to photoelectric sensor, photoelectric sensor is delivered to signal processor after changing light signal into the signal of telecommunication, after signal processor processes, deliver to display, can demonstrate target type, threat level and orientation etc. for information about, and send alarm signal.Can also attack the threat signal data of target in the future and directly deliver to coupled countermeasurer, directly start and control these countermeasurers by interface arrangement.

All kinds of nanometer lasers are accused (in advance) alert device and are used for the tactical support scouting, and what be used for strategfic reconnaissance is nanometer laser information reconnaissance equipment.Nanometer laser information is scouted, and is to be born by nanometer laser reconnaissance and surveillance receiver; Its essence is that the strategy of carrying out in prewar is movable, and in nanometer laser alarm machine, set up a threat data storehouse.This database has the intelligence data of the various lasing light emitters of enemy, comprises pulse repetition frequency, pulsewidth, coded system and the wavelength etc. of the various lasing light emitters of enemy.Even can't see lasing light emitter,, also can discern enemy's type of laser according to the threat data storehouse; The optoelectronic device of guaranteeing one's own side is normal.The nano photoelectric counterweapon is a kind of precision strike enemy's a novel advanced weaponry.

The key technology of nanometer laser alarm machine is a detector.Detector mainly contains three kinds: 1) be used for the nanometer laser detector of visible light near infrared band, its key is a PIN nano photoelectric diode, usually there are two kinds: preface material silicon PIN photoelectric diode and preface material indium GaAs/PPIN, spectral response is respectively 0.4-1.1 micron and 0.95-1.65 micron, and the photosurface diameter is respectively 0.2 centimetre and 0.05 centimetre.2) be used for the nanometer laser detection device of 10.6 micron wavebands, also have two kinds: photoconduction preface material mercury-cadmium tellurid detector and photovoltaic preface material mercury-cadmium tellurid detector, spectral response are all at the 8-12 micrometer range, and the photosurface size is respectively 0.1 centimetre and 0.03 centimetre.3) the triband tellurium has two kinds of structures every the infrared nanometer laser detector of mercury: the shortwave element overlays above the long wave element, the middle laminated construction that binds with saturating infrared epoxy resin; Another kind is a parallel construction.

10.3 nanometer laser is selected suitable nanometer laser light source according to action principle and position in the various application of medical science, medical field.Because it is good etc. that nano laser has small-sized a, high power, removable, easy to operate and performance, will become the main flow of the laser that medical uses.

Er:YAG (2.94 microns), Ho:YAG (2.09 microns), Tm:YAG (2.01 microns) nano laser etc. are to be the new laser of matrix with YAG preface material, can replace existing laser.Therefore the wavelength of Er:YAG nano laser is suitable for the soft tissue effect is also demonstrated the very high ability of evapotranspiring to sclerous tissueses such as teeth simultaneously on the absorption peak of water.Ho:YAG and Tm:YAG nano laser are fit to the silica fiber transmission.

10.4 (Rapid Prototyping, RP) technology belongs to " discrete/as to pile up " shaping to the nanometer laser quick shaping.It is by discrete path, restriction and the mode of piling up of obtaining, by piling up the nano material formation 3D solid that stacks up.The nanometer laser RP technique is integrated in one technology such as CAD, CAM, the driving of CNC elaborate servo, photoelectron and nano material, and the product threedimensional model according to by the CAD structure carries out hierarchy slicing to it, obtains the profile of each layer cross section.According to these profiles, the nanometer laser bundle optionally cuts paper (or curing liquid resin from level to level from level to level, or sintering dusty material from level to level), or injection source optionally sprays from level to level adhesive or hot melt material etc., forms each cross section and progressively is superimposed as three-dimensional objects.It becomes the three-dimensional manufacture simplification of a complexity combination of a series of two dimension processing; Automatically finish the conversion of from electronic model (cad model) to physical model (prototype and part).It can be processed the part of any complex surface shape and complicated inner cavity structure.It can realize material extraction (gas phase, liquid phase, solid phase) process and manufacture process is integrated, design (CAD) is with to make (CAM) integrated etc.

The nanometer laser RP technique will be widely used in various aspects such as machinery, petrochemical industry, electronics, computer, biomedical engineering.

Claims (10)

1. in the solid nano laser, will make bar-shapedly as the matrix (preface material or non-preface material) of nanometer laser, both ends of the surface are polished to optical flat, and have the good depth of parallelism.Plate the reflection nanometer film in both ends of the surface, just constitute optical resonator, also can adopt two speculums to constitute optical resonator in addition.The solid nano laser generally adopts the optical pumping pumping, and pumping source can be continuously luminous or pulsed is luminous; Light source is xenon lamp or high-pressure mercury-vapor lamp normally.Light source can also be used semiconductor light sources in addition, comprises semiconductor light-emitting-diode and semiconductor laser diode; Perhaps light source such as fiber laser.

Following table has been listed the material and the wavelength thereof of some nanometer lasers.

2. the dyestuff nano laser can utilize the tuned cell (grating, prism etc.) that inserts in the resonant cavity to change the frequency of output laser.The light beam of the adjustable dye nano laser of laser pumping and resonant cavity axle form a low-angle (about 3 °).Resonant cavity is made up of reflecting grating and a speculum that is coated with the nanometer deielectric-coating.Rotating shutter just can change the frequency of output laser.

Following table is listed the tuning range (unit: micron) of some nanometer laser dyestuff.

Nano dye Tuning range roughly Nano dye Tuning range roughly Nano dye Tuning range roughly Cresol-purple ??0.64-0.7 Rhodamine-6G ??0.56-0.65 Cumarin ??0.44-0.49 Acridine red ??0.6-0.63 Receive fluorescein ??0.52-0.57 Receive salicylate ??0.39-0.42 Rhodamine-B ??0.58-0.69 The tetramethyl shape ketone that looses ??0.44-0.54 ??POPOP ??0.38-0.44

3. the semiconductor nano laser is by nanometer P in the semiconductor preface material ⁺N ⁺Knot (or PN junction etc.) constitute.Compound semiconductor nano material wherein: periodic table of elements tetrels is a covalent bond, for example diamond, Germanium, silicon, selenium etc.Then semiconductor bielement nano material compounds such as family of four families-four, family of three races-five and family of two families-six have more and more stronger polar covalent bond; Also have semiconductor ternary, quaternary and polynary nanometer material compound.

3.1 that utilizes that the heterostructure of semiconductor preface material causes can be with the poor of discontinuity and refractive index, can make the continuous operation at room temperature of semiconductor nano laser.Semiconductor preface material is the core material that constitutes nano laser.

3.2 the semiconductor nano laser also adopts the preface material of gallium (Ga), arsenic (As), indium (In), phosphorus (P) and aluminium compounds such as (Al) or non-preface material to make usually.The nano laser resonant cavity can utilize and nanometer P ⁺N ⁺The orthogonal preface material of junction plane cleavage surface constitutes Fabry Perot resonator.The preface material cleavage surface of one end plates the high-performance reflectance coating, and the preface material cleavage surface of the other end is as output and reflection end; Be used to realize the nanometer laser concussion.

4. the optical fiber nano laser is as laser medium with nano optical fibers itself; Its resonant cavity is by two end faces bonding chamber sheets of nano optical fibers or plate that nano thin-film constitutes.It also can directly inscribe the nano optical fibers Bragg grating as resonant cavity on the nano optical fibers end face.Its cavity body structure is simple, and the nano optical fibers softness, can be coiled into arbitrary shape in minimum profile curvature radius scope outside sweep.Small and exquisite modular high-power semiconductor laser of volume that its selection emission wavelength and nano optical fibers absorption characteristic are complementary or semiconductor nano laser are as pumping source; Be easy to realize high efficiency and high power.

The optical fiber nano laser can be divided into single layer optical fiber nano laser and double-deck optical fiber nano laser.Double-layer nanometer optical fiber is a kind of nano optical fibers with special construction.It has increased an inner cladding (the inner cladding shape can be circle etc.) than individual layer nano optical fibers, and the lateral dimension of inner cladding and numerical aperture are all much larger than fibre core.Doped with rare-earth elements (Yb, Nd, Er, Tm etc.) in the fibre core of double-deck optical fiber nano laser; Because inner cladding surrounds the periphery of single mode nanometer fibre core, pump light launch in inner cladding and is also repeatedly passed through the nanometer fibre core and be doped ion and absorb, thereby pump light is converted to the single mode nanometer laser efficiently.

5. the nanometer laser material is only slow in its speed of growth, when free space being arranged on every side, could form well-regulated geometry; Because the grain of receiving is different, formation condition (speed of the temperature of liquation, pressure, denseness and condensation etc.) is different, can form various preface materials.This technology should possess two preconditions: one is to satisfy the growth mechanism that the preface material forms; The secondth, should satisfy the technological parameter that the preface material forms.

Nanometer laser material basic generation technology: certain high-purity material melts in containing the fusion crucible that draws preface material equipment of smelting furnace; When the temperature of this material remains the state of its fusing point (or hanging down a bit a little), by the mechanical device (for example clamper) of the seed preface that hauls this kind material (can be seed preface bar, seed preface sheet or seed preface piece) very lentamente along rotation counterclockwise, with immerse in the fused solution of this kind material the seed preface around space temperature remain on fusing point to time between the non-preface condensation point and be pulled upwardly; At first contacting melted material on the seed preface will and receive face angle and born of the same parents' the lattice shape etc. received received according to the face of receiving of this seed preface and at first be formed with the preface material that rule, long-range order are arranged; Form preface material ingot then rallentando along with being pulled upwardly.

Nanometer laser material epitaxy generation technique: with the seed preface (seed preface bar, seed preface sheet or seed preface piece etc.) of certain high-purity material as preface material substrate, allow the atom of this high-purity material be arranged in regularly on the preface material substrate, progressively form have certain type from level to level, function, thickness and than the preface material layer of complete structure.It is divided into chemical vapor deposition techniques and molecular beam epitaxy technique.

In pure laser preface material, suitably mix trace impurity, can make various different purposes, nanometer laser device that precision is high.

Nanometer laser annealing is that the nanometer laser bundle is focused on any material area that needs annealing, even can anneal to the zone of any nanometer scale, can remove effectively to receive the dislocation of grain and the stacking fault of material in the material.

6. the preparation method of cluster laser preface material: graphite arc method etc.It can generate cluster laser preface material and carbon nano-tube laser preface material etc.

The main synthetic method of carbon nano-tube laser preface material: graphite arc method, laser evaporation method and catalystic pyrolysis etc.

Active material is implanted in the carbon nano-tube, made it become biology sensor, can be used for detecting difficult and complicated illness, and be used for the medicine compound probability.

7. the most basic technology of preparing of laser nano composite material: highly purified matrix and fusing point be placed in the fusion crucible that draws preface equipment melt (temperature than the fusing point height of matrix, but lower) than the high decentralized photo quantum powder of matrix or the grain ratio as required of receiving and stir than the fusing point that strengthens body; When the temperature of this liquation drops to the fusing point (or hanging down a bit a little) of matrix, under the environment that keeps this temperature,, very lentamente along rotation counterclockwise the seed crystal in the liquation of this kind of immersion material is pulled upwardly by the mechanical device (for example clamper) that hauls this kind composite material seed crystal (can be seed crystal bar, seed wafer or seed crystal piece); At first the melted material that contacts on the seed crystal will at first be formed with the crystal of rule, long-range order arrangement according to the crystal face of this seed crystal and the lattice shape of interfacial angle and structure cell etc.; Form the nano composite material ingot then rallentando along with being pulled upwardly.

Nanometer laser material preparation method commonly used can be divided into solid phase method, liquid phase method and vapor phase method etc. by technical process mesostroma state.Can prepare various metal dust, oxidate nano laser preface material powder and non-oxidized substance nanometer laser powders such as carbide, nitride by these methods with nanoscale.Mechanical mixture dispersion-moulding-sintering process, liquid phase dispersion-moulding-sintering process, original position generation-moulding-sintering process etc. are arranged in addition.

8. the most basic technology of preparing of laser composite nano materials: highly purified matrix and fusing point be placed in the fusion crucible that draws preface equipment melt (temperature than the fusing point height of matrix, but lower) than the high decentralized photo quantum powder of matrix or the grain ratio as required of receiving and stir than the fusing point that strengthens body; When the temperature of this liquation drops to the fusing point (or hanging down a bit a little) of matrix, under the environment that keeps this temperature,, very lentamente along rotation counterclockwise the seed preface in the liquation of this kind of immersion material is pulled upwardly by the mechanical device (for example clamper) that hauls this kind composite material seed preface (can be seed preface bar, seed preface sheet or seed preface piece); At first the melted material that contacts on the seed preface will at first be formed with the preface material of rule, long-range order arrangement according to the preface face of this seed preface and preface face angle and preface born of the same parents' preface lattice shape etc.; Form compound preface material ingot then rallentando along with being pulled upwardly.

The synthetic method of the compound preface material of laser also has: ion injection, vacuum vapor deposition method, sputtering method, plasma-deposited and sol-gal process etc.

9. laser preface material preparation of devices method: but the high-purity silicon rod draws the fusion crucible in the preface instrument to melt in bavin Laski formula,, at a certain temperature very lentamente along rotation counterclockwise the seed preface silicon that immerses in the molten silicon is pulled upwardly by the mechanical device that hauls seed preface silicon (for example seed preface silicon clamper); At first contact molten silicon on the seed preface silicon and receive lattice and receive face angle etc. and at first be formed with the preface material silicon that rule, long-range order are arranged according to this seed preface silicon; Form preface material silicon ingot then gradually.

When preface material silicon growth, if in molten silicon, mix boron impurities (or phosphorus) atom, just can obtain P type (or N type) laser preface material silicon ingot, through steps such as cutting, grinding, polishings, obtain polishing preface material silicon chip.With this silicon chip is substrate, just can make the nanometer laser device on it.

The many laser preface material silicon diodes of quantity will be made on the nanometer epitaxial wafer.The nanometer extension is a kind of technology of taking chemical reaction method to carry out the growth of preface material.Under certain condition, with the preface material silicon chip (or preface material silicon silk) of substrate as the seed preface, allow atom (as silicon atom) be arranged in gradually on this substrate according to the structure of this seed preface regularly, form one deck and have certain conduction type, resistivity, thickness and the complete preface material layer of receiving lattice structure.But epitaxial growth temperature draws the temperature of molten silicon in the preface instrument much lower than bavin Laski formula.The fusing point that epitaxial growth temperature is lower than silicon is about 30%--50%.

The reduction chemical reaction that silicon compound carried out, the free state silicon atom character of generation is very active, at high temperature has a large amount of heat energy.When it falls silicon atom with substrate preface material surface and clashes into, heat energy is emitted, and row is in its surface successively according to the rule of the atomic arrangement of substrate preface material silicon.The free state silicon atom deposits continuously, fitly forms preface material silicon epitaxy layer according to the structure of seed preface silicon.

Growth technology also can adopt chemical vapor deposition and molecular beam epitaxial method.

10. as long as will replace with the nano laser of making based on the preface material based on the laser that crystal is made.Then nano laser just can be applied to existing applied all fields of laser and scope etc. equally; The three-dimensional quick shaping of for example space nanometer laser communication, nanometer laser, biological manufacturings of nanometer laser, nanometer laser quick shaping, nanometer laser radio communication, nanometer laser demonstration, nanometer laser draw the various aspects such as electrooptical countermeasures of thunder and dispersing fog, nanometer laser range finding, nanometer laser radar, nanometer laser guidance and navigation, nanometer laser processing, nanometer laser nuclear fusion, nanometer laser.Simultaneously nanometer laser also in military affairs, in the medical science, in the energy, in the traffic, in the information, the medium various aspects of communication neutralization materials play a great role.Nanometer laser has fabulous application prospect as media of information at aspects such as optical communication, optical information processing and storage, robot vision.

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