A kind of method that improves solid state laser pumping utilization ratio and products thereof
Technical field
The present invention relates to a kind of method that improves solid state laser pumping utilization ratio, belong to laser and field of optoelectronic devices.
Background technology
Solid state laser is one type of solid state laser that is widely used, extensive application aspect laser processing, laser labelling, scientific research or the like.Solid laser material commonly used has the doped yttrium aluminum garnet class, mixes and fluoridize lithium fluoride like, doped yttrium vanadate and doping potassium-gadolinium class etc., and the characteristics of their absworption peaks are to have a plurality of absworption peaks and discrete each other.Present laser pumping source; Except that diode-end-pumped is to a certain absworption peak, the sunlight of all the other pumping sources such as xenon lamp, bromine tungsten filament lamp, krypton lamp, mercury lamp and proposition in recent years etc., its spectral distribution scope is all than broad; The wave band of the Energy distribution of significant proportion beyond the absworption peak of solid laser material; Especially partly there is the energy of significant proportion to can not get effective utilization the visible light short wavelength,, the heat radiation of solid state laser proposed requirements at the higher level because this part Conversion of energy be hot.
Semiconductor-quantum-point is the granular materials of a kind of size in several nanometers; The preparation method is comparative maturity also; As utilize directly growth quantum point in silicate glass, fluoride glass of high-temperature fusion annealing method, and also can be scattered in the quantum dot in the colloid with the chemical method generation, again these quantum dots are mixed organic optical materials; Like UV glue, PMMA etc., process the solid-state material that is mixed with quantum dot.Such as particle radius is the CdSe semiconductor nano of 2.1nm, and it all has stronger absorption to the light that wavelength is shorter than 600nm, and at the wave band place of 610nm emission peak is arranged.Big characteristics in addition of semiconductor nano; Can be through the quantum dot of preparation variable grain radius; Make its emission peak move to the specified wavelength position, its absworption peak is corresponding mobile also, can customize the semiconductor quantum spot size to the position of the absworption peak of solid state laser like this.
Summary of the invention
The present invention will overcome the existing low shortcoming of solid state laser pumping efficiency, a kind of method that improves solid state laser pumping utilization ratio and products thereof is provided, and need not laser structure is done big adjustment.
The method of raising solid state laser pumping utilization ratio of the present invention comprises the steps:
Step 1; Preparation is mixed with the material for transformation of wave length of semiconductor-quantum-point; The light of the short wavelength of said material for transformation of wave length absorbing solid laser pump light part also is converted into the light at laser material absworption peak place, makes that originally the light in laser material absworption peak scope is not absorbed by laser material;
Step 2 is placed described material for transformation of wave length, on the path of the placement location of described material for transformation of wave length before exciting light is transferred to described solid laser material between described solid laser material and pump light source.
Further, described step 1 adopts fusion method directly in silicate glass or borate glass, to produce quantum dot; Rationally control preparation condition; Make the quantum dot that produces have suitable size; Described quantum dot emission peak is in the absworption peak place of solid laser material; Described quantum dot will be the light that is in the quantum dot absorption spectrum, is converted into the light that can be absorbed by solid laser material, thereby pump energy is provided for solid laser material.
Perhaps, described step 1 comprises:
(1) adopt chemical method to produce the quantum dot that is scattered in colloid; Rationally control preparation condition; Make the quantum dot that produces have suitable size, described quantum dot emission peak is in the absworption peak place of solid laser material, and described quantum dot will be the light that is in the quantum dot absorption spectrum; Be converted into the light that can be absorbed by solid laser material, thereby pump energy be provided for solid laser material;
(2) again these quantum dots are mixed the transparent optical host material and mix, process the solid-state material that is mixed with quantum dot.
Further again, described solid laser material is the doped yttrium aluminum garnet class, mixes and fluoridize lithium fluoride like, doped yttrium vanadate or doping potassium-gadolinium class; The host material of described material for transformation of wave length is silica glass, silicate glass, fluoride glass, optics ultraviolet glue, PMMA or PS; Institute's doped quantum dot is in the described material for transformation of wave length: the CdSe-ZnSe of CdSe or CdS or nucleocapsid structure or CdSe-ZnS or CdS-ZnS; The lateral size of dots of mixing in the described material for transformation of wave length is at 1~10nm.
Adopt the high-performance solid laser pumping of method of the present invention; Comprise solid laser material and pump light source; It is characterized in that: between described solid laser material and pump light source, place a kind of material for transformation of wave length that is mixed with semiconductor-quantum-point; The light of the short wavelength of described material for transformation of wave length absorptive pumping light source part also is converted into the light at described solid laser material absworption peak place, on the path of the placement location of described material for transformation of wave length before exciting light is transferred to described solid laser material.
Further, the laser pumping mode is an end pumping, and the shape of material for transformation of wave length is a sheet.
Further, the laser pumping mode is at the profile pump through laser pump cavity, and the shape of material for transformation of wave length is the tubular with the laser pump cavity similar shape.
Further again, described laser pumping source can be one of xenon lamp, bromine tungsten filament lamp, krypton lamp or sunlight, or its combination.
The present invention is through placing a kind of material for transformation of wave length that is mixed with semiconductor-quantum-point between solid laser material and pump light source; The light of the short wavelength of this wavelength absorption solid laser pumping light part also is converted into the light at laser material absworption peak place, makes that originally the light in laser material absworption peak scope is not absorbed by laser material.The present invention improves the method for solid state laser pumping utilization ratio; The laser that can be used for xenon lamp or sunlight pumping; The laser that both can be used for end pumping also can be used for the laser of profile pump, has to need not laser structure is done advantages such as big adjustment, method be simple.
The principle of invention is following:
Realize through between solid laser material and pump light source, placing a kind of material for transformation of wave length.This material for transformation of wave length is a kind of optical material that is doped with the lead selenide quantum dot of suitable particles radius, and substrate can be optical glass or organic optical materials.When the pump light of laser shines on the material for transformation of wave length, the light of its short wavelength's part is absorbed by material for transformation of wave length, and luminous.The particle radius of choose reasonable quantum dot makes the emission wavelength of material for transformation of wave length be in the absorption bands of solid laser material, makes that originally the light in solid laser material absworption peak scope is not absorbed by solid laser material.
The method of raising solid state laser pumping utilization ratio of the present invention can be used for the solid state laser of xenon lamp, bromine tungsten filament lamp, krypton lamp or sunlight pumping, both can be used for the laser of end pumping, also can be used for the laser of profile pump.
The size of semi-conducting material is reduced to certain size (the Bohr radius of the bound exciton in the semiconductor piece material) when following; Its energy level will produce separate structure; And generation quantum size effect; The center that is its emission peak changes with the size of quantum dot, and the quantum dot that therefore can prepare different size is to produce the wavelength of needs.Because the process characteristic of quantum dot preparation, the quantum dot size of preparation presents a Unimodal Distribution, and the spectrum of generation has certain width (about tens nanometers).Prepare the different quantum dot of particle size under the Different Preparation condition, the centre wavelength of the spectrum that they produce is different.Rationally control preparation condition; The emission peak of the feasible quantum dot that produces is in the absworption peak place of solid laser material; These quantum dots will be the light that is in the quantum dot absorption spectrum, is converted into the light that can be absorbed by solid laser material, thereby pump energy is provided for solid laser material.
The preparation of material for transformation of wave length has two kinds of basic skills: the one, and utilize fusion method directly in glass, to produce quantum dot, can be silicate glass or borate glass; The 2nd, produce the quantum dot that is scattered in colloid with chemical method, again these quantum dots are mixed transparent optical material and mix (like optics ultraviolet glue, PMMA etc.), process the solid-state material that is mixed with quantum dot.
The pump mode of laser has two kinds of end pumping and profile pumps.For the end pumping form, be prepared into tabular to the solid-state material that is mixed with quantum dot, the tangent plane of size and laser crystal is suitable, and is placed on the end of laser crystal.If profile pump, being prepared into cylindrical tubular to the solid-state material that is mixed with quantum dot, inner surface should be fitted closely with the cylindrical outer surface of laser crystal, and the solid-state material that perhaps will be mixed with quantum dot evenly covers the inner surface of laser condenser.
Advantage of the present invention is: energy utilization efficiency improves.
Description of drawings
Fig. 1 adopts a kind of structural representation of end pumping mode for the present invention.
Among Fig. 1: 1-material for transformation of wave length, 2-laser chamber mirror, 3-solid laser material, 4-pump light source.
Fig. 2 adopts a kind of structural representation of profile pump mode for the present invention.
Among Fig. 2: 11-material for transformation of wave length, 22-laser chamber mirror, 33-laser material, 44-pump light source, 55-laser pump cavity.
Fig. 3 is mixed with the emission spectrum of material for transformation of wave length that particle radius is the selenizing chromium quantum dot of 2.1nm for the present invention.
Fig. 4 is the absorption spectrum of neodymium-doped potassium-gadolinium laser crystal of the present invention.
Fig. 5 is mixed with the absorption spectrum of material for transformation of wave length that particle radius is the selenizing chromium quantum dot of 2.1nm for the present invention.
Embodiment
Below in conjunction with accompanying drawing and embodiment the present invention is described further:
Embodiment 1:
With reference to accompanying drawing 1,3,4,5:
Improve the method for solid state laser pumping utilization ratio, comprise the steps:
Step 1; Preparation is mixed with the material for transformation of wave length of semiconductor-quantum-point; The light of the short wavelength of said material for transformation of wave length absorbing solid laser pump light part also is converted into the light at laser material absworption peak place, makes that originally the light in laser material absworption peak scope is not absorbed by laser material;
Step 2 is placed described material for transformation of wave length, on the path of the placement location of described material for transformation of wave length before exciting light is transferred to described solid laser material between described solid laser material and pump light source.
Described step 1 adopts fusion method directly in silicate glass or borate glass, to produce quantum dot; Rationally control preparation condition; Make the quantum dot that produces have suitable size; Described quantum dot emission peak is in the absworption peak place of solid laser material; Described quantum dot will be the light that is in the quantum dot absorption spectrum, is converted into the light that can be absorbed by solid laser material, thereby pump energy is provided for solid laser material.
Perhaps, described step 1 comprises:
(1) adopt chemical method to produce the quantum dot that is scattered in colloid; Rationally control preparation condition; Make the quantum dot that produces have suitable size, described quantum dot emission peak is in the absworption peak place of solid laser material, and described quantum dot will be the light that is in the quantum dot absorption spectrum; Be converted into the light that can be absorbed by solid laser material, thereby pump energy be provided for solid laser material;
(2) again these quantum dots are mixed the transparent optical host material and mix, process the solid-state material that is mixed with quantum dot.
Described solid laser material is the doped yttrium aluminum garnet class, mixes and fluoridize lithium fluoride like, doped yttrium vanadate or doping potassium-gadolinium class; The host material of described material for transformation of wave length is silica glass, silicate glass, fluoride glass, optics ultraviolet glue, PMMA or PS; Institute's doped quantum dot is in the described material for transformation of wave length: the CdSe-ZnSe of CdSe or CdS or nucleocapsid structure or CdSe-ZnS or CdS-ZnS; The lateral size of dots of mixing in the described material for transformation of wave length is at 1~10nm.
Adopt the high-performance solid laser pumping of method of the present invention; Comprise solid laser material 3 and pump light source 4; Between described solid laser material 3 and pump light source 4, place a kind of material for transformation of wave length 1 that is mixed with semiconductor-quantum-point; The light of the short wavelength of described material for transformation of wave length 1 absorptive pumping light source 4 part also is converted into the light at described solid laser material 3 absworption peak places, being placed on the path before exciting light is transferred to described solid laser material 3 of described material for transformation of wave length 1.
The laser pumping mode is an end pumping, and the shape of material for transformation of wave length 1 is a sheet.Described pump light source 4 can be one of xenon lamp, bromine tungsten filament lamp, krypton lamp or sunlight, or its combination.
Make a solid laser material 3 according to Fig. 1 and be the solid state laser of neodymium-doped potassium-gadolinium; Adopt the mode of end pumping; Pump light source 4 can be xenon lamp, bromine tungsten filament lamp, krypton lamp or sunlight; Exciting light imports from the left side of laser crystal, and the chamber mirror 2 in process material for transformation of wave length 1 and left side shines on the solid laser material 3.The spectrum (Fig. 3) of emission peak of material for transformation of wave length 1 that is mixed with selenizing chromium quantum dot is at 598nm; The spectral width of emission peak is approximately 25nm; The absworption peak (Fig. 4) of contrast neodymium-doped potassium-gadolinium can find out that the emission peak of material for transformation of wave length 1 and the absworption peak of neodymium-doped potassium-gadolinium coincide better.Absorption spectrum (Fig. 5) by the material for transformation of wave length 1 that is mixed with selenizing chromium quantum dot can be found out; 1 pair of wavelength of the material for transformation of wave length of selenizing chromium quantum dot has good absorption characteristic less than the light of 598nm; Material for transformation of wave length 1 arrives the 598nm place with the power conversion of this part light; Make wavelength can be absorbed by the solid laser material 3 of neodymium-doped potassium-gadolinium, thereby improve pumping efficiency less than the energy of that part of light of 598nm.
Embodiment 2:
With reference to accompanying drawing 2,3,4,5:
The difference of present embodiment and embodiment one is that the laser pumping mode changes at the profile pump through laser pump cavity 5, and the shape of material for transformation of wave length 11 is the tubulars with laser pump cavity 5 similar shapes.
Make a laser material 33 according to Fig. 2 and be the solid state laser of neodymium-doped potassium-gadolinium; Adopt the mode of profile pump; Pump light source 44 can be xenon lamp, bromine tungsten filament lamp or krypton lamp; Exciting light covers material for transformation of wave length 11 through the side of laser pump cavity 55 importing laser crystals 33 at the inner surface of laser pump cavity 55 or the side of laser crystal 33.
Other explanation of present embodiment is like the explanation of embodiment 1.