CN1088635A - The Yttrium aluminium garnet laser crystal of neodymium-doped, terbium and cerium and technology of preparing thereof - Google Patents
The Yttrium aluminium garnet laser crystal of neodymium-doped, terbium and cerium and technology of preparing thereof Download PDFInfo
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Abstract
The present invention relates to neodymium-doped, terbium and cerium yttrium aluminum garnet (Nd, Tb, Ce): YAG laser crystals and preparation method thereof, comprise crystal composition and crystalline the growth, technology such as aftertreatment and processing.Also relate to being incorporated in the air-cooled medium and small energy pulse laser apparatus of repetition rate when higher.The preparation of raw material when last method is grown this crystal, the aspects such as selection of type of heating and growth parameter(s).Crystal of the present invention have (Nd, Ce): YAG
[7]Advantage, and its heat effect be better than (Nd, Cc): YAG, especially under thermal focal, air-cooled repetition rate, aspect the energy distribution of the beam divergence of light beam and light beam, obviously be better than (Nd, Ce): YAG.Therefore, its suitableeer ∴
Description
The present invention relates to a kind of new laser crystals, specifically, is the laser crystals [(Nd, Tb, Ce): YAG] of neodymium-doped, terbium and cerium.Also relate to this crystalline technology of preparing,, particularly relate to this crystalline and draw growing technology comprising crystal growth, annealing and processing technology.It is of the present invention that (Ce): the YAG crystal can be used as the working-laser material of solid statelaser, also can be used as fluorescent material, the material of window material or some other optical element for Nd, Tb.
Because Nd:YAG has good physicochemical characteristic, and cheap, it remains now uses in the solid statelaser field at most and the most general laser crystals
[1]But Nd:YAG also has unsatisfactory part, and its disadvantage is that lasing efficiency is not high enough and threshold value is low inadequately.These shortcomings are very limited its application under air-cooled condition.People are always for improving its efficient effort for many years.An effective way that improves the Nd:YAG lasing efficiency is to mix sensitized ions in crystal again, utilizes it to arrive Nd
3+Thereby energy shift the utilization ratio that improves pump light efficient improved.As is generally known, Cr
3+It is exactly a sensitized ions preferably
[2]But in YAG, Cr
3+→ Nd
3+Energy transfer efficiency not high, sensibilized is not ideal enough.Holloway
[3], KoBaJIeBa
[4], Mares
[5]And Kvapil
[6]Research Deng the people points out that Ce is arranged in YAG
3+To Nd
3+Quantity of radiant energy shift, also exist radiationless energy to shift, and transfer efficiency is higher.But these researchs are also pointed out, because Ce
3+Ionic radius too big, utilize Ce
3+Come sensitization Nd:YAG meeting grievous injury crystalline optical quality.Therefore, they think, from general effect, utilize a large amount of Ce
3+Sensitization Nd:YAG is disadvantageous, can only mix the Ce of trace
3+Improve the laser activity of Nd:YAG.
The applicant is in another granted patent
[7]In successfully solved above-mentioned a large amount of Ce that mix
3+The problem of bringing had both made full use of Ce
3+Sensibilized, avoid or eliminated a large amount of Ce again
3+Infringement to optical homogeneity.It is high by 70% to have grown pulse laser efficiency ratio Nd:YAG, and optical homogeneity is good, can under air-cooled repetition rate, use and also cheap (Nd, Ce): the YAG crystal.But this crystal in use, exposed new problem.Outstanding behaviours is excessive in the beam spreading of laser beam, is particularly comparing with the water-cooled condition, and it is excessive to cool off under the not enough air-cooled condition beam divergence, and along with the raising of laser repetition rate, beam divergence increases sharply.Under the service condition of general Ping-Ping laser cavity, the energy distribution of laser beam is the variation with the raising of repetition rate also.This shows that (Nd, Ce): the heat effect of YAG is bigger.Though it is as described in [7], it can use than under the high ambient temperature, relatively more responsive to the temperature non in the laser bar.Obviously, these shortcomings are very disadvantageous to the application under the air-cooled repetition rate.
Purpose of the present invention provide exactly a kind of promptly have [7] described (Nd, Ce): the advantage of YAG, and heat effect is than (Nd, Ce): YAG is low, under air-cooled repetition rate working conditions, the beam divergence of laser beam than (Nd, Ce): new laser crystals and technology of preparing thereof that YAG is little.
The present invention is yttrium aluminum garnet [(Nd, Tb, Ce): the YAG] laser crystals of a kind of neodymium-doped, terbium and cerium, it is characterized in that it is by Nd, Tb, and Ce, Y, Al and O etc. are elementary composition, and chemical formula is Y
3-a-b-cNd
aTb
bCe
cAl
5O
12, a=1.0 * 10 wherein
-4～7.5 * 10
-2, b=1.0 * 10
-4, c=is greater than 0～4.5 * 10
-2, this crystal belongs to isometric system, and spacer is O
10 h-Ia3d lattice parameter is with a, and the value of b and c and slight change are roughly 12.02
Near.
Another content of the present invention is that (Ce): YAG crystalline preparation method comprises crystalline growth, aftertreatment and optics processing for Nd, Tb.It is characterized in that adopting the pulling method growth of resistance or induction heating, comprising the calcination of powder, press chemical formula Y
3-x-y-zNd
xTb
yCe
zAl
5O
12Batching, x=5 * 10 wherein
-4～0.375, y=1.1 * 10
-4～1.5, z=is greater than 0～0.36, the powder of preparation through ground and mixed and pre-compaction forming be placed on be heated in the crucible molten, seed crystal is rotated and draws growth down, its main growth conditions is: the crystal rotating speed is 8～150r/min; Pull rate is 0.3～2.5mm/h; Protective atmosphere is reductibility or neutral atmosphere; Seed crystal can be any direction, but preferential with＜111 〉,＜110〉or＜211〉direction; The ratio of the diameter of crystal equal-diameter part and crucible interior diameter is less than 1/2.
It is of the present invention that (Ce): the also available Bridgman method of YAG crystal, molten-salt growth method or flame method growth, its post-processing technology can be by another granted patent of the applicant for Nd, Tb
[8]Carry out, but in annealing temperature, suitable adjustment need be done in soaking time and warming and cooling rate aspect.The processing of crystalline optics is undertaken by Processing Criterion and the service requirements of common Nd:YAG, and this is well-known to those skilled in the art.
It is of the present invention that (Ce): the YAG crystal can be used as the material of working-laser material, fluorescent material, window or some other optical element for Nd, Tb.
Now details are as follows with the present invention:
As previously mentioned, (Nd, Ce): though advantage such as the efficient height of YAG, threshold value be low, when it used under the insufficient or air-cooled condition of cooling, its light beam beam divergence was bigger, but also strengthened rapidly with the increase of laser repetition rate.Meanwhile, the energy distribution of light beam also degenerates.We think that the reason of these problems of generation may be (Nd, Ce): the heat effect of YAG is excessive, though it can use under higher envrionment temperature, but when cooling is abundant inadequately, temperature in the laser bar is uneven, and (Nd, Ce): the YAG crystal may compare sensitivity to this temperature non, thereby causes more serious heat distortion.In fact, the laser crystals of sensitization type all might have more serious heat effect, because the luminous energy that sensitized ions absorbed then finally will disengage with the form of heat as can not all being transferred to active ions, thereby increases the weight of the hot distortion effect of crystalline.Obviously, near sensitized ions, particularly near the microcell that sensitized ions is concentrated, this heat effect is even more serious.And on the other hand, because Ce
3+Ratio of ionic radii Y
3+Big a lot, at Ce
3+Near, Ce particularly
3+Near the microcell that ion is concentrated, more serious lattice distortion was just arranged originally.Uneven heat effect must increase the weight of the microcell distortion of lattice, and we think that this may be that (Nd, Ce): YAG has the distored reason of serious heat.Moreover uneven heat effect increases the weight of the microcell distortion of lattice, may make some change of crystal field in distortion district.Therefore, this heat effect not only shows increasing the weight of of thermal lensing effect on macroscopic view, also might influence the output characteristic of laser.
Based on above analysis, we think that a possibility approach that addresses the above problem be to seek the more weak new sensitized ions of heat effect.Another may approach be (Nd, Ce): among the YAG, mix other ion and improve its heat effect.On principle, in crystal, mix certain dopant ion, might change the temperature factor of crystalline coefficient of thermal expansion, thermal conductivity, specific refractory power and specific refractory power to a certain extent.Therefore, (Nd, Ce): mix certain ion among the YAG again, might improve its heat effect.We find a kind of new ion Tb finally through for many years a large amount of experiments
3+, this is to have no precedent in the prior art document. and the present invention uses Tb
3+Partly or entirely replace (Nd, Ce): the Ce among the YAG
3+, and become (Nd, Tb, Ce): YAG.
Tb:YAG is with (Tb, Ce): YAG can be used as fluorescent material, has many people its spectrum and fluorescent characteristic have been carried out more detailed research
[9-11]Tb
3+Absorption peak 273,325,357 and the 380nm place.Preceding two strong absorption peaks belong to 4f → 5d transition, and latter two weak absorption peak belongs to the f-f transition.And its fluorescence is some more sharp-pointed peaks, can be divided into two groups, wherein one group corresponding to
5D
3→
7The F transition is distributed between 380～470nm, another the group corresponding to
5D
4→
7The F transition is distributed between 490～630nm.The strongest fluorescence is Ce among 545nm and the YAG
3+Fluorescence peak close.And in 490～630nm wave band, a large amount of Nd are arranged
3+Absorption peak, therefore, we estimate that Tb is arranged in YAG
3+→ Nd
3+The resonance radiation energy shifts or shifts by means of the off-resonance of phonon is fully possible.Above-mentioned work points out that also Tb is arranged in YAG
3+()/() Ce
3+Energy shift to exist, but according to these reports, Tb
3+()/() Ce
3+Energy shift, strengthened Tb
3+ 5D
4→
7F fluorescence and Ce
3+The yellow green light district.Obviously, this mutual transfer process to energy by radiative transfer to Nd
3+Be favourable.Moreover, be 8 o'clock in ligancy, Tb
3+Ionic radius be 1.04
(drawing from Kaminski work " laser crystals ") is with Y
3+(1.02
) very approaching.So Tb
3+Do not mix and can cause serious lattice distortion.We find unexpectedly, terbium mix the temperature factor that can change crystalline thermal expansivity, thermal conductivity, specific refractory power and specific refractory power to a certain extent, this just might make the hot distortion effect of crystalline improve.In a word, we think to have Tb
3+→ Nd
3+Energy shift and Tb
3+Mix improvement (Nd, Ce): the hot distortion effect of YAG crystalline.These are exactly basic design of the present invention, do not see the report of relevant this design so far as yet.
Obviously, Y of the present invention
3-a-b-cNd
aTb
bCe
cAl
5O
12The concentration of each dopant ion is influential to the crystalline various characteristics in the laser crystals, for example Nd
3+Concentration to Nd in lasing efficiency, threshold value, the crystal
3+Fluorescence lifetime and crystal optics quality etc. all have a strong impact on, this is a called optical imaging.In [7], discussed Ce
3+Concentration to (Nd, Ce): YAG crystal influence, of the present invention (Nd, Tb, Ce): among the YAG, Ce
3+Concentration identical influence is also arranged.Same Tb
3+Concentration crystalline laser output and heat effect etc. are also had tangible influence.
Another part of the present invention be (Nd, Tb, Ce): the technology of preparing of YAG, comprising links such as crystalline growth, aftertreatment and light processing.Of the present invention (Nd, Tb, Ce): the YAG crystal, can adopt pulling method, also available Bridgman method, flame method or molten-salt growth method are grown.The present invention preferentially selects pulling method for use.But no matter adopt what method, all must be noted that the purity of raw material, purity will have a strong impact on the crystalline laser activity inadequately.The purity of the used various raw materials of the present invention is 4N～6N.Moreover because Ce and Tb are the elements that easily appraises at the current rate, they are the tetravalence attitude in oxidizing atmosphere, and the present invention to require Tb and Ce be three valence states, therefore, the protective atmosphere during growth must be reductibility or neutral atmosphere.After the growth (Nd, Tb, Ce): the YAG crystal, must carry out anneal, the colour center that forms in the crystal when growing in reducing atmosphere to eliminate
[6](Ce): this aftertreatment of YAG crystalline can be with reference to another part patent of the applicant for Nd, Tb
[8], but aspect annealing temperature and soaking time and warming and cooling rate, do suitable adjustment.As is generally known the optics processing quality of laser crystals has a strong impact on laser output, in some uses, also to some particular requirement of processing of laser crystals.Of the present invention (Nd, Tb, Ce): the processing of YAG crystalline optics, can process by the working method of General N d:YAG or according to service requirements.
The present invention preferentially selects pulling method growth (Nd for use, Tb, Ce): the YAG crystal, various oxide raw materials all need be through abundant calcination to remove adsorbed moisture before batching, to guarantee accurate feed proportioning and the volatile impunty that removes absorption, calcination temperature is 800～1300 ℃, and soaking time is 4～20 hours.Press chemical formula Y then
3-x-y-zNd
xTb
yCe
zAl
5O
12Prepare burden.Be noted that to make and contain desirable each dopant ion concentration in the crystal (a, b c), must consider the segregation coefficient of each dopant ion when crystallization.By the concentration in the desirable crystal (a, b, c) and the segregation coefficient of actual measurement or reported in literature
[7]Decide x, y and z in the batching chemical formula.X=5 * 10 that the present invention is used
-4～0.375, y=1.1 * 10
-4～1.5, z=is greater than 0～0.36.After preparation of powder is finished, grind fully and mix, various raw materials are mixed.Pre-compaction forming then is again through 1100～1600 ℃ of calcinations (also can not calcination).Should point out emphatically, in each process such as batching, ground and mixed and shaping, must be strictly on guard against and sneak into other impurity, particularly detrimental impurity such as iron.
Pulling method growth (Ce): during the YAG crystal, can utilize the heating of graphite or tungsten constant resistance, crucible also can utilize intermediate frequency or high-frequency induction heating with molybdenum or tungsten crucible for Nd, Tb, and this moment crucible iridium crucible.Make when being heated by resistive, its thermal field structure synoptic diagram as shown in Figure 1.1 is seed rod among the figure, the 2nd, and seed crystal, the 3rd, crystal, the 4th, melt, 5,6,7th, heat protection screen on the molybdenum, the 8th, crucible, the 9th, crucible holder, 10,11,12nd, molybdenum side heat protection screen, the 13rd, inner shield tube, the 14th, resistance heater, the 15th, pallet, the 16th, battery lead plate, the 17th, molybdenum platform cover, the 18th, connection piece, the 19th, aluminum oxide pad.When using induction heating, the synoptic diagram of its thermal field structure figure such as accompanying drawing 2.Wherein 1 is seed rod, the 2nd, and the crystal pulling hole, the 3rd, seed crystal, the 4th, the zirconium dioxide stay-warm case, the 5th, crystal, the 6th, vision slit, the 7th, melt, the 8th, the iridium crucible, the 9th, ruhmkorff coil, the 10th, the zirconium dioxide insulation is husky, and the 11st, heat-preservation cylinder, the 12nd, pallet.
With the raw material of the pre-compaction forming crucible of packing into, place above-mentioned thermal field then, close fire door and vacuumize by requirement of generally drawing growth of Nd: YAG and method, fill protective atmosphere.Then gradually the heating, treat that melt fully fuses after, seed crystal gradually descends.After seed crystal contact melt is also stable, the beginning pulling growth.In the process of beginning pulling growth, need suitably to adjust temperature at following seed crystal.Can grow with the seed crystal of any direction (Nd, Tb, Ce): the YAG crystal, the present invention preferentially selects for use＜and 111 〉,＜110〉and＜211〉direction, but preferably use＜111 ± 5 ° seed crystal.In the initial period and general growth of Nd of growth: YAG is the same, needs to receive neck and shouldering process.Crystal diameter during isodiametric growth should be less than 1/2 of crucible interior diameter.Crystal diameter is preferably 1/2.5～1/4 with the ratio of crucible interior diameter.The front illustrates that (Ce): YAG crystalline insulation atmosphere must be reductibility or neutral atmosphere, and the protective atmosphere that the present invention uses is the Ar of purity as 4N, also available N for Nd, Tb in growth
2Or Ar+H
2, N
2+ H
2And Ar+N
2. moreover temperature accuracy is very important to crystal growth, the present invention require temperature-controlled precision be not less than ± 0.5 ℃.
As is generally known after growing system comprised that thermal field and temperature controlling system are selected, the selection of growth parameter(s) was vital to the quality of crystal mass.For example the crystalline rotating speed is exactly an important growth parameter(s).Because the big young pathbreaker of rotating speed influences the shape of growth interface and the thickness of forward position, interface diffusion layer, and the stability of rotating speed also can influence the crystalline optical homogeneity.When rotating speed was lower than the quick passage critical speed of liquid-flow state transformation, the interface was protruding in melt, and when being higher than quick passage critical speed, the interface is flat or recessed.And the height and the crystalline diameter of the size of the size of quick passage critical speed and crucible and shape, melt are relevant.These all are called optical imaging.Therefore, as will then adjusting to the subcritical rotating speed to the crystal rotating speed with protruding interface growth according to above-mentioned factor.Otherwise, as will be, then need adjust to the crystal rotating speed and be higher than quick passage critical speed with plane interface growth.The used speed range of the present invention is 8～150r/min, the above-mentioned factor decision when specifically numerical value is according to growth.When plane interface growth, the stability influence of rotating speed is bigger, and its instantaneous fluctuating must not surpass ± 0.5r/min.
Another important growth parameter(s) is the crystalline pull rate.Pulling rate is crossed conference, and to produce component cold excessively, particularly for growth (Nd, Tb, Ce): YAG, the many and Ce of dopant ion
3+And Nd
3+Ionic radius too big, segregation coefficient is very little, pull rate more can not be excessive.The too small crystal that then may make of pulling rate is grown in too frequent growth-melt back-regrowth process, and this will make striation stress increase the weight of and lose time and the energy.Can be according to the thermal field that uses, the factors such as size of dopant ion concentration and crystal diameter are selected pull rate, and in general, concentration height or crystal diameter are big, and pulling rate should be little, on the contrary pulling rate can suitably be accelerated.The used pulling rate of the present invention is 0.3～1.5mm/h when protruding interface is grown, and is 0.5～2.5mm/h when plane interface growth.
It is of the present invention that (Ce): the YAG crystal also can adopt the Bridgman method for Nd, Tb, and molten-salt growth method or flame method are grown.The worker knows as crystal growth, with the growth of Bridgman method the time, is that the material that will prepare pre-compaction forming is contained in the crucible, place thermal field then with certain temperature gradient, by slow decline crucible, or the well heater that slowly rises, or the method for temperature that slowly descends is grown.Crucible can suitable in addition rotation, also can not rotate, and the crucible material can be used iridium, molybdenum or tungsten, garden tubular or other shape at the bottom of it is shaped as the garden tubular or has taper.When using molten-salt growth, at first be to choose certain fusing assistant.Fusing assistant commonly used has PbO, PbF
2, KF, B
2O
3And composition thereof etc.Then with fusing assistant and (Ce): YAG crystalline raw material is prepared by a certain percentage for Nd, Tb.Confected materials is packed into after fully grinding and mixing in platinum or the platinum rhodium crucible, places to have thermal field that certain temperature distributes and be heated to moltenly, and the temperature that fully slowly descends again after the fusion is grown.The crucible shape can be the garden tubular, also is with point garden tube or other shape at the end, in process of growth, for making crystal in crucible bottom nucleation and growth, can carry out suitable cooling to the crucible bottom.These are all to similar with molten-salt growth Nd:YAG or other garnet crystal.(Ce): the YAG crystal, its method is to similar with flame method growth sapphire or Nd:YAG for Nd, Tb in also available flame method growth.
Example 1:
Each oxide compound (Al through calcination
2O
3, Ce
2O
3, Tb
2O
3, Nd
2O
3) raw material presses chemical formula Y
3-x-y-zNd
xTb
yCe
zAl
5O
12Title is joined, x=0.120 wherein, and y=0.012, z=0.006. raw material gross weight is 600 grams.Claim confected materials mixed grinding in shredder to pack into after 24 hours (shared four layers) in the special latex rubber bag, place pre-compaction forming in the oil press.The material that is shaped is packaged goes in Φ 80 * 40mm crucible of molybdenum sheet punching press.Then crucible is placed in the thermal field shown in the accompanying drawing 1.Closed furnace door vacuumizes by the method for common growth of Nd: YAG, fills Ar gas.Utilize graphite heater (14 in the accompanying drawing 1) to be heated to fusing fully gradually.Seed crystal gradually descends.The seed crystal direction is＜111〉± 5 °.When seed crystal contact liquid level, stopping to descend and adjusting melt temperature makes it reach the temperature that is suitable for drawing growth.Stablized again 1 hour, and began pulling growth then.The crystalline rotating speed is 80r/min, and pull rate is 2mm/h.The diameter of crystal equal-diameter part is controlled at 28～31mm.Temperature-controlled precision is not less than ± and 0.5 ℃.When finishing growth, manually mention crystal and make it just break away from liquid level, stop then lifting and outage when slowly being cooled to 600 ℃, the time of this temperature-fall period is 12 hours.Cool to room temperature after the outage with the furnace to finish whole growth process.
Example 2:
The title of component, raw material join and the pre-compaction forming process identical with example 1, different is that the raw material gross weight is 1.5kg, uses the device shown in Φ 90 * 90mm iridium crucible and the accompanying drawing 2 and utilizes Frequency Induction Heating.The crystal rotating speed is 15r/min, and pull rate is 1.0mm/h.Other process of growth is also identical with example 1.
Component, type of heating, crucible and the main growth parameter(s) of other growth example of the present invention are all listed in the table 1.Other process and method is identical with example 1 or example 2.
Table 1. other example of the present invention
| Component | Type of heating | Crucible | Growth parameter(s) | Remarks | ||||
| X | Y | Z | Rotating speed r/min | Pulling rate mm/h | ||||
| Example 3 | 0.150 | 0.900 | 0.015 | Resistance | φ 80 * 40mm |
15 | 1.0 | |
| Example 4 | 0.300 | 0.200 | 0.005 | Resistance | φ 80 * 40mm molybdenum pot | 80 | 1.2 | |
| Example 5 | 0.240 | 1.000 | 0.008 | Resistance | φ 80 * 40mm molybdenum pot | 85 | 1.5 | |
| Example 6 | 0.120 | 0.500 | 0.100 | Resistance | φ 80 * 40mm molybdenum pot | 85 | 1.0 | |
| Example 7 | 0.150 | 0.012 | 0.006 | Induction | φ 90 * 90mm |
15 | 0.6 | |
| Example 8 | 0.120 | 0.060 | 0.006 | Induction | φ 90 * 90mm molybdenum pot | 85 | 1.5 | |
| Example 9 | 0.150 | 0.030 | 0.075 | Resistance | φ 80 * 80mm molybdenum pot | 85 | 2.0 | |
| Example 10 | 0.090 | 0.090 | 0.003 | Resistance | φ 80 * 80mm molybdenum pot | 85 | 2.2 | |
Each embodiment gained (Nd, Tb, Ce): the YAG crystal, can satisfy practical requirement fully aspect optical homogeneity.The extinction ratio overwhelming majority of Φ 5 * 70～80mm laser bar surpasses 25dB; Interferogram generally can reach 0.2～0.5/inch.This crystal not only has the efficient height, threshold value is low reaches (Nd, Ce): other advantage of YAG, with (Nd, Ce): YAG compares, and it is having clear improvement aspect the hot distortion effect.Under the stability of laser output, thermal focal, maximum continuous power output, air-cooled repetition rate the aspects such as energy distribution of the beam divergence of light beam, light beam all be better than [7] (Nd, Ce): YAG.Therefore, it is than (Nd, Ce): YAG is more suitable for the application under the application under the air-cooled repetition rate, particularly higher repetitive frequency.Obviously, this crystal has extensive and significant using value.
What accompanying drawing 3 provided is the test result of thermal focal, and curve 1,2nd among the figure, different components (Nd, Tb, Ce): YAG crystal, curve 3 be use always (Nd, Ce): YAG crystal, crystalline size are Φ 5 * 80mm.Measuring method is that crystal is placed in the laser pump cavity, with the krypton lamp irradiation, makes crystal produce thermal lensing effect.With micropore light hurdle and the He-Ne flash ranging distance of the discharging of the coke.X-coordinate is a power input among the figure, and ordinate zou is the thermal focal that records.From then on figure can see (Nd, Tb, Ce): YAG obviously be better than (Nd, Ce): YAG.At continuous output facet same result is arranged also accordingly therewith.(Nd, Ce): the output rating of YAG strengthens the phenomenon that descends with power input and occurs early, and (Ce): the decline phenomenon of YAG occurs lately, and peak power output also will improve 30% for Nd, Tb.
Accompanying drawing 4 is distribution curves of using the power that obtains apart from the micropore at 4.5 meters of outgoing mirror along the middle line sweep of output facula continuously.For ease of contrasting with the pulse-repetition frequency hot spot, this test is carried out under low power.The power input of accompanying drawing 4A is 0.7KW, and the power input of accompanying drawing 4B is 1.4KW.Curve 1 among two figure be (Nd, Tb, Ce): YAG, curve 2 be (Nd, Ce): YAG.As seen from the figure, the beam diameter when no matter being the diameter of full light beam or the l/e place that power drops to maximum power, (Nd, Tb, Ce): the YAG crystal all be significantly less than (Nd, Ce): YAG.
Obviously, the contrast direct reaction of above-mentioned spot diameter has gone out the difference of beam divergence angle.Aspect energy distribution, when power input was higher, (Ce): the advantage of YAG also was very tangible for Nd, Tb.Obviously, its this approximate Gaussian distribution is very favorable to practical application.The contrast of the laser facula under repetition rate is air-cooled also has similar rule.
Accompanying drawing 4A reflect (Nd, Tb, Ce): YAG aspect efficient than (Nd, Ce): YAG is poor, but this does not illustrate Tb
3+No sensitization effect is from Tb
3+The life test of fluorescence spectrum and 544nm fluorescence sees that Nd is being arranged
3+Crystal in, Tb
3+ 5D
4→
7The F peak obviously reduces, and fluorescence lifetime is also by no Nd
3+The time 3.5ms reduce to 2.37ms, though may be because specimen in use or test set difference, the Tb that surveys
3+Fluorescence lifetime than the height of reported in literature, but variation tendency is sure.These spectrum tests result confirms to have Tb in YAG
3+→ Nd
3+Energy shift.And the efficient that Fig. 4 A is reacted low may mainly be the emission spectrum and the Tb of used krypton lamp
3+The serious mismatch of absorption spectrum due to.In a word, from the measuring result and the Tb of above-mentioned heat effect aspect
3+Fluorometric investigation is the result see, aforementioned the present invention is about having Tb
3+→ Nd
3+Energy shift and mix Tb
3+May improve that (Nd, Ce): the basic thought of YAG crystalline heat effect has obtained certainly and confirmed.
It is of the present invention that (Ce): the YAG crystal can be used as the material of working-laser material, fluorescent material, window or other optical element for Nd, Tb.It is particularly suitable for the pulsed laser of higher repetitive frequency work, especially air-cooling laser.Accompanying drawing 5 are us with (Nd, Tb, Ce): the laser apparatus synoptic diagram that the YAG crystal is made, 1 is total reflective mirror among the figure, 2 is laser pump cavity, 3 is pump light source, 4 be (Nd, Tb, Ce): the YAG rod, 5 is refrigerating unit, 6 is outgoing mirror, 7 is power supply.This laser apparatus is can provide satisfied practical function under the 20pps in air-cooled repetition rate.
The reference that this paper quoted all in this literary composition in conjunction with reference.
Reference
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[4]H.C.KoBaлeBa и дp.，ж.пpиk.Cпekт.T27，546（1977）
[5]J.A.Mares，Czech，J.Phys.B35，883（1985）;
B36，1079（1986）;Rev.Phys.Appl.V22，145（1987）
[6] J.Kvapil et al., Czech, J.Phys.B34,581(1984) Czech patents 240641
[7] Zhai Qingyong etc., the patent publication No. CN1030798A of the People's Republic of China (PRC),
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[11] Wang Zhihua etc., luminous with show, V3,46(1982)
Claims (10)
1, the yttrium aluminum garnet of a kind of neodymium-doped, terbium and cerium [(Nd, Tb, Ce): YAG] laser crystals is characterized in that it is by Nd, Tb, and Ce, Y, Al and O etc. are elementary composition, and chemical formula is Y
3-a-b-cNd
aTb
bCe
cAl
5O
12, a=1.0 * 10 wherein
-4～7.5 * 10
-2, b=1.0 * 10
-4～1.4, c=is greater than 0～4.5 * 10
-2, this crystal belongs to isometric system, and spacer is O
10 h-Ia3d lattice parameter is with a, the value of b and c and slight change, but roughly 12.02
Near.
2,, it is characterized in that chemical formula Y according to the crystal of claim 1
3-a-b-cNd
aTb
bCe
cAl
5O
12In a=1.2 * 10
-2～6.0 * 10
-2, b=1.2 * 10
-3～6.0 * 10
-2, c=is greater than 0～3.0 * 10
-3
It is 3, a kind of that (Ce): YAG crystalline preparation method comprises crystalline growth, aftertreatment and optics processing for Nd, Tb; It is characterized in that adopting the growth of drawing of resistance or induction heating, comprising the calcination of powder, press chemical formula Y
3-x-y-zNd
xTb
yCe
zAl
5O
12Batching, wherein x=5 * 10
-4～0.375, y=1.1 * 10
-4～1.5, z=is greater than 0～0.36, and the powder of preparation is through grinding, and mixes and pre-compaction forming is placed on and is heated to moltenly in the crucible, and following seed crystal is rotated and draws growth; Its main growth conditions is: the crystal rotating speed is 8～150r/min; Pull rate is 0.3～2.5mm/h; Protective atmosphere is reductibility or neutral atmosphere; Seed crystal can be any direction, but preferentially select for use＜111,＜110 or＜211〉direction; The ratio of the diameter of crystal equal-diameter part and crucible interior diameter is less than 1/2.
4,, it is characterized in that adopting the graphite resistance heating according to the described method of claim 3; Crucible is with molybdenum or tungsten crucible; The crystal rotating speed is transferred to and is suitable for protruding interface growth; Pull rate is 0.5～1.4mm/h.
5,, it is characterized in that the crystal rotating speed is transferred to and be suitable for plane interface growth according to claim 3 and 4 described methods; Pull rate is 0.8～2.2mm/h.
6,, it is characterized in that adopting induction heating and iridium crucible according to the described method of claim 3; The crystal rotating speed is transferred to and is suitable for protruding interface growth, and pull rate is 0.3～1.3mm/h.
7,, it is characterized in that the crystal rotating speed is transferred to and be suitable for plane interface growth according to claim 3 and 6 described methods; Pull rate is 0.7～2.0mm/h.
8, according to the described method of claim 4, it is characterized in that adopting the tungsten resistive heating.
9, according to the described method of claim 5, it is characterized in that adopting the tungsten resistive heating.
10, a kind of laser apparatus comprises pump light source, laser pump cavity, total reflective mirror, outgoing mirror and power supply, it is characterized in that its working-laser material is the device that claim 1 or 2 described crystal are made.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 93121298 CN1028884C (en) | 1993-12-29 | 1993-12-29 | Yttrium aluminium garnet laser crystal doped with Nd, Tb and Ce, and preparing tech. |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 93121298 CN1028884C (en) | 1993-12-29 | 1993-12-29 | Yttrium aluminium garnet laser crystal doped with Nd, Tb and Ce, and preparing tech. |
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|---|---|
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| CN1028884C CN1028884C (en) | 1995-06-14 |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100376508C (en) * | 2005-04-30 | 2008-03-26 | 中国科学院理化技术研究所 | Gel burning synthetic method for preparing reodymium doped gadolinium-gallium garnet nano powder |
| CN101338453B (en) * | 2008-07-16 | 2011-02-16 | 成都东骏激光股份有限公司 | Growth method of large size non-core YAG series laser crystal |
| CN103074685A (en) * | 2013-02-01 | 2013-05-01 | 中山大学 | High concentration Nd-doped YAG laser crystal growth method |
| CN103469298A (en) * | 2013-08-22 | 2013-12-25 | 昆山开威电子有限公司 | Growth method of cerium-doped yttrium aluminium garnet single crystal by adopting kyropoulos method and high-temperature furnace |
| CN104746135A (en) * | 2013-12-27 | 2015-07-01 | 成都晶九科技有限公司 | Growth method of induction furnace planar-interface large-sized neodymium-doped yttrium aluminium garnet crystal |
| CN106087056A (en) * | 2016-08-03 | 2016-11-09 | 成都新源汇博光电科技有限公司 | A kind of growth technique for YAG crystal |
-
1993
- 1993-12-29 CN CN 93121298 patent/CN1028884C/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100376508C (en) * | 2005-04-30 | 2008-03-26 | 中国科学院理化技术研究所 | Gel burning synthetic method for preparing reodymium doped gadolinium-gallium garnet nano powder |
| CN101338453B (en) * | 2008-07-16 | 2011-02-16 | 成都东骏激光股份有限公司 | Growth method of large size non-core YAG series laser crystal |
| CN103074685A (en) * | 2013-02-01 | 2013-05-01 | 中山大学 | High concentration Nd-doped YAG laser crystal growth method |
| CN103469298A (en) * | 2013-08-22 | 2013-12-25 | 昆山开威电子有限公司 | Growth method of cerium-doped yttrium aluminium garnet single crystal by adopting kyropoulos method and high-temperature furnace |
| CN104746135A (en) * | 2013-12-27 | 2015-07-01 | 成都晶九科技有限公司 | Growth method of induction furnace planar-interface large-sized neodymium-doped yttrium aluminium garnet crystal |
| CN104746135B (en) * | 2013-12-27 | 2017-04-19 | 成都晶九科技有限公司 | Growth method of induction furnace planar-interface large-sized neodymium-doped yttrium aluminium garnet crystal |
| CN106087056A (en) * | 2016-08-03 | 2016-11-09 | 成都新源汇博光电科技有限公司 | A kind of growth technique for YAG crystal |
| CN106087056B (en) * | 2016-08-03 | 2019-02-01 | 成都新源汇博光电科技有限公司 | A kind of growth technique for YAG crystal |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1028884C (en) | 1995-06-14 |
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