CN1912195A

CN1912195A - Growth method of doped-vanadium yttrium-iron-garnet crystal

Info

Publication number: CN1912195A
Application number: CN 200610029502
Authority: CN
Inventors: 苏良碧; 李红军; 张丹; 徐军
Original assignee: Shanghai Institute of Optics and Fine Mechanics of CAS
Current assignee: Shanghai Institute of Optics and Fine Mechanics of CAS
Priority date: 2006-07-28
Filing date: 2006-07-28
Publication date: 2007-02-14
Anticipated expiration: 2026-07-28
Also published as: CN100427649C

Abstract

The invention relates to a vanadium mixed yttrium aluminum garnet vanadium crystal growing method. It adopts traditional crystal pulling method, falling crucible method, or temperature gradient method to grow V: YAG crystal. Its feature is that it adopts graphite heating element, or filling CO or H2 reducing gas into furnace or adding Si4+ or Zr4+ ion into feed proportioning. This method can increase the ratio of V3+ to V ion which is tetrahedron with 1.0-1.5um saturable absorption band.

Description

The growth method of doped-vanadium yttrium-iron-garnet crystal

Technical field

The invention belongs to optics and photoelectron material field, relate to crystal growth, particularly a kind of doped-vanadium yttrium garnet (V:YAG) crystalline growth method.

Background technology

Q-switch solid laser has output laser pulse weak point, peak power advantages of higher, is widely used in fields such as medical science, optical-fibre communications, measuring technology and nonlinear opticses.Than active Q-switching, that passive Q-switch has is simple in structure, volume is little, low cost and other advantages and being widely used.Early stage passive Q-adjusted material generally adopts organic dye and colour centre crystal, yet these materials have short shortcoming of poor chemical stability, work-ing life, are unfavorable for work steady in a long-term.Recently it is found that Cr ⁴⁺: the YAG crystal has wide absorption band and good saturated absorption characteristic at 0.9～1.2 mu m waveband, is mainly used in the passive Q-adjusted of Nd laser apparatus 1.06 μ m places.Doped-vanadium yttrium-iron-garnet crystal (V:YAG) is a kind of novel saturable absorption material, the saturable absorption band covers 1.0～1.5 μ m, broad application background is more arranged: can be used as Nd laser apparatus 1.06 μ m and 1.34 μ m (referring to Applied PhysicsB 1998,67:555～558; SPIE 2004,5460:292～302), and the passive Q-switch of Er laser apparatus 1.54 μ m (referring to AppliedOptics 2005,44:1704～1708).The human eye safe waveband 1.54 μ m laser apparatus that have special important application by the acquisition of frequency displacement 1.34 μ m laser (referring to Instruments and Experimental Techniques2005,48:239-240), have higher efficient than 1.06 μ m.Therefore, V:YAG has become one of most important passive Q-switch material.

1.0～1.5 μ m saturable absorption bands of V:YAG belong to the V of tetrahedron case ³⁺Ion.And V can present in the YAG crystal+3 ,+4 ,+multiple valence states, particularly tetrahedron case such as 5 are very beneficial for high valence state (＞+3) V ionic and exist.Therefore, the tetrahedron case V that adopts the V:YAG crystal of general melt method for growing to contain ³⁺Concentration is very low, almost detects the existence less than above-mentioned saturable absorption band, must improve its concentration (referring to SPIE 1999,3724:329-333 through complicated reducing atmosphere The high temperature anneal; Optical Engineering 2002,41:1976-1982).Must take aftertreatment technology, this has not only increased V:YAG crystalline cost, has also increased the production cycle.

In sum, V:YAG has been widely used in producing the high-peak power laser pulse of several typical laser wavelength 1.06 μ m, 1.34 μ m and 1.54 μ m as a kind of saturable absorber with absorption band of non-constant width (about 500nm).But,, how to improve tetrahedron case V in the V:YAG crystal in order to improve the passive Q-adjusted performance of V:YAG crystalline ³⁺Ratio be the important techniques problem that needs solve.

Summary of the invention

Main purpose of the present invention is will overcome above-mentioned technology formerly to be difficult to obtain high density tetrahedron case V ³⁺The ionic shortcoming provides a kind of growth method of doped-vanadium yttrium-iron-garnet crystal, to improve the tetrahedron case V that produces 1.0～1.5 μ m saturable absorption bands in the crystal ³⁺Ion accounts for all V ionic ratios.

The technology of the present invention solution is as follows:

A kind of growth method of doped-vanadium yttrium-iron-garnet crystal adopts traditional crystal pulling method, falling crucible method or temperature gradient method growth V:YAG crystal, it is characterized in that the type of heating of V:YAG crystal growing process adopts graphite heater, or charges into CO or H in the burner hearth ₂Reducing gas, or add the Si of high valence state in the proportioning raw materials ⁴⁺Or Zr ⁴⁺Ion.

In the time of the heating of described employing graphite resistance heating element, in the burner hearth for vacuum state or charge into inert protective gas or charge into CO or H ₂Reducing gas.

When described type of heating is induction heating or resistive heating, charge into CO or H in the burner hearth ₂Reducing gas.

The Si that adds high valence state in the described proportioning raw materials ⁴⁺Or Zr ⁴⁺Ion is by 0.1%～10% adding SiO that adds V ion atoms percentage composition in the raw material ₂Or ZrO ₂Mode add.

We adopt inductively coupled plasma atomic emission spectrum to test V ionic overall weight percentage concentration in the V:YAG crystal of growing according to growth method of the present invention.Record thus that V:YAG crystalline V concentration is 0.25wt% in the specific embodiment 2, calculate atomicity volumetric concentration (N ₀) be 1.3 * 10 ²⁰/ cm ³After cutting of crystal blank process and the polished finish, adopt Jasco V-570UV/VIS/NIR spectrophotometer test V:YAG crystalline room temperature absorption spectrum.According to the absorption cross (σ) of V:YAG crystal at 1342nm wavelength place in the uptake factor (α) at the 1342nm place of practical measurement and the document is 7.2 * 10 ^-18Cm ², can calculate tetrahedron V in the crystal ³⁺Ionic atomicity volumetric concentration (N ₁): N ₁=α/σ.In the specific embodiment of the invention 2 V:YAG crystalline absorption spectrum as shown in Figure 2, the uptake factor of 1342nm is 0.82cm ^-1, calculate tetrahedron V thus ³⁺Ionic atomicity volumetric concentration is 2.2 * 10 ¹⁷/ cm ³N ₁Divided by N ₀Be tetrahedron V ³⁺Ion accounts for all V ionic ratios in the crystal.This ratio is 0.17% in the embodiment of the invention 2.This numerical value is big more, shows that promptly employed growing method helps tetrahedron V more ³⁺Ionic forms.

According to the present invention, the worker in this field makes improvements on the basis of existing growth apparatus, perhaps adopts composition of raw materials of the present invention, can obtain to have at 1.0～1.5 mu m wavebands the V:YAG crystal of saturable absorption characteristic low-cost, expeditiously.

Description of drawings

Fig. 1 be the inventive method at the induction heating crystal pulling method at H ₂The V:YAG crystal of growing under the atmosphere (thickness is 2.2mm) see through spectrum.

Fig. 2 adopts the absorption spectrum of the V:YAG crystal (thickness is 5.5mm) that graphite resistance Heating temperature gradient method grows under high-purity (＞99.995%) Ar atmosphere for the present invention.

Embodiment

The invention will be further described below in conjunction with embodiment.

Embodiment 1:

Adopt V ₂O ₅, Al ₂O ₃, Y ₂O ₃Make initial feed, V ₂O ₅Doping content be 0.20at%, mix the back on hydropress briquetting, be put in the iridium crucible.Use the induction heating Czochralski grown crystal, make seed crystal through X-ray diffractometer accurate pointing normal line of butt end direction for the YAG single crystal rod of [111], growth atmosphere is mobile H ₂The crystal blank of growth is deep green, and from blank cutting fritter sample, grinding the content that adopts ICP-AES to measure V in the crystal in the back is 0.14at%, is converted into the atomicity volumetric concentration and equals 3.2 * 10 ¹⁹/ cm ³Cutting thickness is the wafer of 2.6mm from the crystal blank, and optical polish to thickness is 2.2mm, adopts the test of Jasco V-570UV/VIS/NIR spectrophotometer to see through spectrum as shown in Figure 1.The uptake factor that converses the 1342nm place is 0.24cm ^-1, divided by its absorption cross 7.2 * 10 ^-18Cm ², calculate tetrahedron V in the crystal ³⁺Ionic atomicity volumetric concentration is 3.36 * 10 ¹⁶/ cm ³, accounting for all V ionic ratios is 0.11%.

Embodiment 2:

Adopt V ₂O ₃, Al ₂O ₃, Y ₂O ₃Make initial feed, V ₂O ₃Doping content be 0.78at%, mix back briquetting on hydropress, be put in the molybdenum crucible, crucible bottom is placed with through X-ray diffractometer accurate pointing normal line of butt end direction and is the YAG single crystal rod seed crystal of [111].Use the gradient furnace growing crystal of graphite heater heating, growth atmosphere is that purity is higher than 99.995% argon gas.The crystal blank of growth is deep green, and from blank cutting fritter sample, grinding the content that adopts ICP-AES to measure V in the crystal in the back is 0.58at%, is converted into the atomicity volumetric concentration and equals 1.3 * 10 ²⁰/ cm ³Cutting thickness is the wafer of 6.0mm from the crystal blank, and optical polish to thickness is 5.5mm (behind the plated film as shown in Figure 2), adopts Jasco V-570UV/VIS/NIR spectrophotometer test absorption spectrum as shown in Figure 3, and the uptake factor at 1342nm place is 1.56cm ^-1, divided by its absorption cross 7.2 * 10 ^-18Cm ², calculate tetrahedron V in the crystal ³⁺Ionic atomicity volumetric concentration is 2.2 * 10 ¹⁷/ cm ³, accounting for all V ionic ratios is 0.17%.

Embodiment 3:

Adopt V ₂O ₅, Al ₂O ₃, Y ₂O ₃, SiO ₂Make initial feed, wherein V ₂O ₃Doping content be 0.80at%, SiO ₂Doping content be 0.008at%, mix back briquetting on hydropress, be put in the molybdenum crucible, crucible bottom is placed with through X-ray diffractometer accurate pointing normal line of butt end direction and is the YAG single crystal rod seed crystal of [111].Use the gradient furnace growing crystal of graphite heater heating, growth atmosphere is that purity is higher than 99.995% argon gas.The crystal blank of growth is deep green.

Embodiment 4:

Adopt V ₂O ₅, Al ₂O ₃, Y ₂O ₃Make initial feed, wherein V ₂O ₅Doping content be 0.50at%, mix back briquetting on hydropress, be put in the molybdenum crucible, crucible bottom is placed with through X-ray diffractometer accurate pointing normal line of butt end direction and is the YAG single crystal rod seed crystal of [111].Use the crucible decline stove growing crystal of graphite heater heating, growth atmosphere is CO.It is green that the crystal blank of growth is.

Embodiment 5:

Adopt V ₂O ₃, Al ₂O ₃, Y ₂O ₃Make initial feed, wherein V ₂O ₃Doping content be 0.50at%, mix back briquetting on hydropress, be put in the molybdenum crucible, crucible bottom is placed with through X-ray diffractometer accurate pointing normal line of butt end direction and is the YAG single crystal rod seed crystal of [111].Use the crucible decline stove growing crystal of graphite heater heating, growth atmosphere is H ₂The crystal blank of growth is deep green.

Embodiment 6:

Adopt V ₂O ₅, Al ₂O ₃, Y ₂O ₃, SiO ₂Make initial feed, wherein V ₂O ₃Doping content be 0.60at%, ZrO ₂Doping content be 0.012at%, mix back briquetting on hydropress, be put in and use the induction heating Czochralski grown crystal in the iridium crucible, make seed crystal through X-ray diffractometer accurate pointing normal line of butt end direction for the YAG single crystal rod of [111], growth atmosphere is higher than 99.995% argon gas for mobile purity.The crystal blank of growth is deep green.

Claims

1, a kind of growth method of doped-vanadium yttrium-iron-garnet crystal adopts traditional crystal pulling method, falling crucible method or temperature gradient method growth V:YAG crystal, it is characterized in that the type of heating in the V:YAG crystal growing process adopts graphite heater, or charges into CO or H in the burner hearth ₂Reducing gas, or add the Si of high valence state in the proportioning raw materials ⁴⁺Or Zr ⁴⁺Ion.

2, the growth method of doped-vanadium yttrium-iron-garnet crystal according to claim 1, when it is characterized in that the heating of described employing graphite resistance heating element, in the burner hearth for vacuum state or charge into inert protective gas or charge into CO or H ₂Reducing gas.

3, the growth method of doped-vanadium yttrium-iron-garnet crystal according to claim 1 when it is characterized in that described type of heating is induction heating or resistive heating, charges into CO or H in the burner hearth ₂Reducing gas.

4, the growth method of doped-vanadium yttrium-iron-garnet crystal according to claim 1 is characterized in that in the described proportioning raw materials adding the Si of high valence state ⁴⁺Or Zr ⁴⁺Ion is by 0.1%～10% adding SiO that adds V ion atoms percentage composition in the raw material ₂Or ZrO ₂Mode add.