CN105870772A - Laser gain chip, laser assembly, power amplifier and oscillator - Google Patents

Abstract

The invention relates to a laser gain chip, a laser assembly, a power amplifier and an oscillator, and belongs to the technical field of laser equipment. The laser gain chip comprises a laser source, a gain medium, a pumping source and cooling fluid, wherein the pumping source comprises a diode array and a coupling device which are connected; the laser source, the coupling device and the cooling fluid are respectively arranged in a way of corresponding to different side surfaces of the gain media; the transmission directions of cooling fluid, pumping light and laser are in perpendicular quadrature; a gradual change doping structure is arranged inside the gain medium along the transmission direction of the pumping light. The three fields including the pumping field, the laser field and the cooling fluid field are in perpendicular quadrature; the space coupling in the three fields is relieved, so that each field can be independently controlled; in addition, each gain medium has a unique pumping source; a plurality of laser gain chips are in cascade connection in the laser transmission direction; the power expansion can be realized; the operation is convenient; the engineering implementation is facilitated.

Description

A kind of laser gain chip and laser module, power amplifier and agitator

Technical field

The invention belongs to laser equipment technical field, relate in particular to a kind of laser gain chip and laser group Part, power amplifier and agitator.

Background technology

High-average power laser has a wide range of applications in fields such as national defence, industry, scientific researches.High in repetition Lath-shaped, laminated or flake gain media can be typically used with in device of high power laser.Lath The advantage of shape medium is to constrain in inside lath by laser beam in the way of total reflection transmission, this transmission light Road is referred to as in a zigzag (Zig-Zag) light path, and to have homogenized the optics of lath thickness direction uneven for light path in a zigzag Property, reduce the thermal lensing effect thus caused and the birefringence effect caused by stress.Pumping schemes is by just The laser diode-side-pumped of phase is developed to end-pumping, is improved to a centimetre amount from millimeter magnitude by the absorption length of pumping light Level, it is ensured that the efficient absorption of pumping light, improves laser instrument aggregate efficiency.The lath of application light path in a zigzag Solid state laser patent includes: 3,633,126；6,094,297；6,134,258 grades (U.S.).Laminated medium Advantage to be laser transmit along interarea direction, and through interarea, owing to lamination interarea size is relatively big, Fresnel Number is relatively big, thus is prone to multi-disc and realizes laser energy and power expansion along interarea direction stacking, and laser aid is tied Structure is compact.The solid state laser patent of application laminated includes: US 7,366,211；CN 103650261 A Deng.The advantage of sheet medium is that Laser Transmission direction is basically identical with conduction of heat direction, and thermograde exists In laser propagation direction, each several part before laser wave experiences identical variations in temperature, thus, thermal distoftion is very Little, it is ensured that higher beam quality.The solid state laser patent of application sheet medium includes: 3,631,362； 6,339,605 grades (U.S.).

Although lath-shaped, laminated or flake gain media have a lot of advantage, but, applying to weight Frequently high energy and device of high power laser there is also deficiency.In lath-shaped laser aid, owing to need to ensure to dissipate Heat energy power, causes medium thin, the laser chances of losing games be the end face of medium and bore little, be limited to diffraction loss with Media size, the fan-out capability of monolithic lath is limited.Single-link merit is realized along medium length direction multi-disc stacking During rate extension, it is difficult to ensure that the compact of laser aid, as patent is told 4,761,059 and 7,436,588 is (beautiful State) use multilink Laser coherent combining to realize high-power output.Optics coherence tomography is spatially equivalent to increase Laser beam size, owing to beam separation can not eliminate, causes far field beams power dissipation, and beam quality is not Reach, be unfavorable for that it is applied.In laminated laser aid, pumping light and laser share the interarea of lamination, The uniformity of pumping light field will directly affect the uniformity of laser near-field, want during multi-disc vertical stack power expansion Seek higher pump intensity degree (such as 20kW/cm²), the several tens cm magnitude that diode array need to be sent Light beam contracting bundle to centimetres, such as patent 5,307,430 and 6, what 160,934 (U.S.) used hollow leads Pipe, its essence is a conical reflecting system, and laser beam compression necessarily causes the angle of divergence to increase, thus, contracting bundle After the conformal transmission range of pumping light short, about at centimetres.Laminated laser power is limited to distribution all Even, high intensity and the pumping light that can transmit.In flake laser aid, owing to the absorber thickness of thin slice exists Hundred micron dimensions, one way is low to the absorption efficiency of pumping light.Patent 6,577,666 and 6,891,874 (U.S.) Based on parabolic mirror the super many journeys pumping structure announced, utilizes this structure pumping light Multiple through then out thin slice Efficient pumping can be realized, but this pumping structure is complicated.Thin slice typically use after interarea cooling mode, laser Being exported after rear interarea reflects by front principal plane is incident, the light path of this amplification is referred to as " V " shape and amplifies light path.Adopt Realizing power expansion by the mode of multiple amplifying head module-cascades, for making full use of pump field, intermodule uses Image relaying system, the length dimension often increasing a module laser aid need to increase by four times of focal lengths, and tens of pieces thin The laserresonator that sheet is constituted is up to 50 meters, and structure is complicated, bulky, it is more difficult to ensure the steady of laser aid Qualitative.

Summary of the invention

For all deficiencies of prior art, in order to solve the problems referred to above, it is proposed that a kind of pump field, laser Field, cooling three perpendicular laser gain chips of fluid field and laser module, power amplifier and vibration Device, has gain and is uniformly distributed, is obtained in that higher beam quality, is prone to the feature of power expansion.

For achieving the above object, the present invention provides following technical scheme:

A kind of laser gain chip, including lasing light emitter, gain media, pumping source and cooling fluid, described pump Source, Pu includes diode array and the coupling device being connected, described lasing light emitter, coupling device and cooling fluid The not ipsilateral of the most corresponding gain media is arranged, and described cooling fluid, pump light, the transmission side of laser Inside perpendicular quadrature, described gain media, the transmission direction along pump light is set to gradient doping structure.

Further, described gain media is set to laminated structure, and it includes center, mistake the most successively Crossing layer and covering, described center and covering are disposed as gradient doping structure, and described transition zone is set to non- Doped dielectric, the active ions of the internal doping in described center are Nd³⁺Or Yb³⁺, the internal correspondence of described covering is mixed Miscellaneous active ions are Sm³⁺Or Cr⁴⁺, along the transmission direction of pump light, described center excited inside ion Doping content is the Long-term change trend that low centre, two ends is high.

Further, the doping content of described center excited inside ion is:

By

Draw:

$n_d=\frac{g_0}{{\mathrm{\σ}}_{em}}\frac{1+{\mathrm{CI}}_{Ps}}{B+{\mathrm{AI}}_{Ps}}=\frac{g_0}{{\mathrm{\σ}}_{em}}\frac{I_{Ps}^{+}+C\[{\left(I_{Ps}^{+}\right)}^2+(1-{\mathrm{\η}}_P){\left(I_{Ps,in}^{+}\right)}^2\]}{{\mathrm{BI}}_{Ps}^{+}+A\[{\left(I_{Ps}^{+}\right)}^2+(1-{\mathrm{\η}}_P){\left(I_{Ps,in}^{+}\right)}^2\]},$

Wherein, n_dRepresent the doping concentration distribution of center excited inside ion, η_PRepresent pump light absorption efficiency, g₀Represent small-signal gain, I_Ps,inRepresent the pumping light intensity that gain media both sides are total, I⁺ _Ps,inRepresent gain media list The pumping light intensity of side, and meetI_PsRepresent the local pumping light intensity in gain media, I⁺ _PsTable Showing that single-side pumping light transmits direction distribution in gain media along it, described light intensity is pumping light intensity and pumping The ratio of saturated light intensity, with the central point of center as zero, x represents the position along pumping optical transmission direction Putting, W represents the center length along pumping optical transmission direction, σ_absWith σ_emRepresent Pumping light absorption cross section respectively With Laser emission cross section, A, B, C represent the hot population characteristic of dopant ion.

Further, described diode array includes symmetrically arranged diode array one centered by gain media With diode array two, described diode array one and diode array two are respectively by coupling device and gain Medium connects, and described coupling device is set to banded structure, and it is made up of multifiber, described coupling device Height equal with the height of center, described pumping source sets at least to one, and adjacent coupled device is along it Width arranges, and the overall width of coupling device is not more than the width of center.

Further, the side that described gain media is corresponding with lasing light emitter is coated with laser anti-reflection film, described laser Transmit along the direction being perpendicular to described side, and through gain media, described coupling device sets with gain media It is set to plane-plane contact, the side that described gain media contacts with coupling device is coated with pump light anti-reflection film, institute State pump light internal along optic path in a zigzag at gain media.

Separately, the present invention also provides for a kind of laser module, including above-mentioned a kind of laser gain chip, described sharp Gain of light chip is multiple along the cascade of Laser Transmission direction, and the spacing of adjacent laser chip gain is millimeter magnitude.

Separately, the present invention also provides for a kind of single laser cavity power amplifier, comprises above-mentioned a kind of laser gain core Sheet, described laser gain chip cascades multiple composition laser modules, adjacent laser gain along Laser Transmission direction The spacing of chip is millimeter magnitude, arranges front cavity mirror one and Effect of Back-Cavity Mirror one, described ante-chamber at described laser module Mirror one, Effect of Back-Cavity Mirror one are total reflective mirror, are provided with quarter wave plate one at described Effect of Back-Cavity Mirror one.

Separately, the present invention also provides for a kind of bidifly optical cavity power amplifier, comprises above-mentioned a kind of laser gain core Sheet, described laser gain chip separately constitutes laser module one and laser group along the cascade of Laser Transmission direction is multiple Part two, the spacing of the adjacent laser chip gain being in same laser module is millimeter magnitude, described laser 90 ° of polarization apparatus rotors it are provided with between assembly one and laser module two.

Separately, the present invention also provides for a kind of agitator, includes front cavity mirror two, above-mentioned a kind of laser gain successively Chip and Effect of Back-Cavity Mirror two, described laser gain chip cascades multiple composition laser modules along Laser Transmission direction, The spacing of adjacent laser chip gain is millimeter magnitude, and described front cavity mirror two is set to total reflective mirror, described back cavity Mirror two is set to partially reflecting mirror.

The invention has the beneficial effects as follows:

1, in the present invention, the not ipsilateral of lasing light emitter, coupling device and cooling fluid corresponding gain media respectively sets Put, promote pump field, laser field and cooling three perpendicular quadratures of fluid field, relieve three couplings spatially Close so that each field can independently control, beneficially engineering construction.

2, in the present invention, inside gain media, transmission direction along pump light is set to gradient doping structure, protects In card gain media, gain is uniformly distributed, and this structure is highly suitable for quasi-three-level gain media or low suction Receive the gain media of coefficient.

3, in the present invention, center and covering are disposed as gradient doping structure, and transition zone is set to undoped and is situated between Matter, thus ensure that pump light is absorbed in center, transition zone effectively reduces the temperature ladder of center surrounding Degree, reduces the depolarization loss caused by thermic stress birfringence, and covering can fully absorb spontaneous emission light, Inhibit the self-oscillation that gain media is horizontal, it is ensured that the high-gain ability of gain media.

4, in the present invention, laser gain chip is multiple along the cascade of Laser Transmission direction, power expansion can be realized, Each gain media is obtained in that in having independent pumping source, and each gain media that identical small-signal increases Benefit, and gain profiles is uniform, pump energy and the heat production density of absorption have identical distribution, at power In expansion process, it is not required to consider that other factors affect, simple operation, meanwhile, adjacent laser chip gain Spacing is millimeter magnitude, and compact conformation takes up room little.

5, in the present invention, pump light is internal along optic path in a zigzag at gain media, has considerably long absorption Length, the concentration adulterated by design is distributed, it can be ensured that high absorption efficiency and pumping homogeneity.

6, in the present invention, coupling device is formed by multifiber arrangement, when pumping source sets at least to one, many Individual coupling device arranges along its width, is favorably improved pump power density, simultaneously as often The output light field distribution of individual coupling device is identical, therefore, it is possible to while improving pump power, it is ensured that good Good pumping homogeneity.

Accompanying drawing explanation

Fig. 1 is the overall structure schematic diagram of the present invention；

Fig. 2 be the present invention Fig. 1 in A-A cross-sectional view；

Fig. 3 be the present invention Fig. 1 in B-B cross-sectional view；

Fig. 4 is the gain medium structure schematic diagram of the present invention；

Fig. 5 is the coupling mechanism structure schematic diagram of the present invention；

Fig. 6 is the laser module plan structure schematic diagram of the present invention；

Fig. 7 is single laser cavity power amplifier structure schematic diagram of the present invention；

Fig. 8 is the bidifly optical cavity power amplifier structure schematic diagram of the present invention；

Fig. 9 is the oscillator structure schematic diagram of the present invention；

Figure 10 (a) is Nd in the embodiment of the present invention five³⁺The concentration distribution of ion linear doping and small-signal gain Distribution relation figure；

B () is Nd in the embodiment of the present invention five³⁺The concentration distribution of ion gradient doping and small-signal gain Distribution relation figure；

Figure 11 (a) is Yb in the embodiment of the present invention six³⁺The concentration distribution of ion linear doping and small-signal gain Distribution relation figure；

B () is Yb in the embodiment of the present invention six³⁺The concentration distribution of ion gradient doping and small-signal gain Distribution relation figure.

In accompanying drawing: 1-gain media, 101-center, 102-transition zone, 103-covering, 104-grow tall face, 105- Wide high surface, 106-length and width face, 2-pumping source, 201-diode array one, 202-diode array two, 203- Coupling device, 204-optical fiber, 3-laser, 4-pump light, 5-cool down fluid, 6-laser module shell, 61-window Mouth, 62-housing, 7-fluid circulator, 8-fluid line, 9-lasing light emitter, 10-beam-expanding system one, 11-polarization Sheet one, 12-45 ° of faraday, 13-45 ° of quartzy rotor, 14-polaroid two, 15-front cavity mirror one, 16-reflecting mirror One, 17-reflecting mirror two, 18-Image relaying system one, 19-1/4 wave plate one, 20-Effect of Back-Cavity Mirror one, 21-reflecting mirror three, 22-beam-expanding system two, 23-reflecting mirror four, 24-polaroid three, 25-Image relaying system two, 26-1/4 wave plate two, 27-Image relaying system three, 28-90 ° of polarization apparatus rotor, 29-Image relaying system four, 30-reflecting mirror five, 31-electric light Switch, 32-polaroid four, 33-reflecting mirror six, 34-laser module one, 35-laser module two, 36-front cavity mirror Two, 37-Effect of Back-Cavity Mirror two.

In Figure 10, axis of abscissas represents the length of gain media, and unit is cm, and main axis of ordinates represents Nd³⁺ The doping concentration distribution of ion, unit is 10¹⁸/cm³, secondary axis of ordinates represents small-signal gain, and unit is cm^-1, Dotted line represents that small-signal gain, solid line represent Nd³⁺The doping concentration distribution of ion.

In Figure 11, axis of abscissas represents the length of gain media, and unit is cm, and main axis of ordinates represents Yb³⁺ The doping concentration distribution of ion, unit is 10¹⁹/cm³, secondary axis of ordinates represents small-signal gain, and unit is cm^-1, Dotted line represents that small-signal gain, solid line represent Yb³⁺The doping concentration distribution of ion.

Detailed description of the invention

In order to make those skilled in the art be more fully understood that technical scheme, attached below in conjunction with the present invention Figure, carries out clear, complete description to technical scheme, based on the embodiment in the application, this Other similar embodiment that field those of ordinary skill is obtained on the premise of not making creative work, All should belong to the scope of the application protection.

Embodiment one:

As Figure 1-3, a kind of laser gain chip, including lasing light emitter, gain media 1, pumping source 2 and cold But fluid 5, described pumping source 2 includes diode array and the coupling device 203 being connected, described diode battle array Row include symmetrically arranged diode array 1 and diode array 1, institute centered by gain media 1 State diode array 1, diode array 1 to be connected with gain media 1 by coupling device 203 respectively, Described coupling device 203 is set to banded structure, and it is formed by multifiber 204 arrangement, itself and gain media 1 It is set to plane-plane contact, utilizes the advantage of coupling device 203 flexible transfer, improve diode array and be situated between with gain Matter 1 degree of freedom spatially, it is simple to pumping source 2 and gain media 1 are arranged, heat management.

Described lasing light emitter, coupling device 203 are arranged with the not ipsilateral of cooling fluid 5 corresponding gain media 1 respectively, Promote pump field, laser field and cooling three perpendicular quadratures of fluid field, the transmission direction of the most described cooling fluid 5 With pump light 4, the transmission direction perpendicular quadrature of laser 3, relieve three couplings spatially so that each Individual field all can independently control, beneficially engineering construction.

Being coated with laser anti-reflection film on the side that described gain media 1 is corresponding with lasing light emitter, described laser 3 is along vertically Transmit in the direction of described side, and through gain media 1, described gain media 1 contacts with coupling device 203 Side on be coated with pump light anti-reflection film, promote described pump light 4 internal along light path in a zigzag at gain media 1 Transmission.

As preferably, described pump light 4 transmits, when the length of gain media 1 along the longest edge of gain media 1 During while be longest edge, described in grow tall and be coated with laser anti-reflection film on face 104, described wide high surface 105 is coated with pump light Anti-reflection film, described laser 3 transmits along the direction, face of growing tall 104 being perpendicular to gain media 1, grows tall face 104 size relatively Greatly, Fresnel number is relatively big, and described pump light 4 transmits along wide high surface 105 direction being perpendicular to gain media 1, promotees Make between the pump light 4 face of growing tall 104 in gain media 1 along optic path in a zigzag, there is considerably long absorption Length, is effectively increased absorption efficiency and pumping homogeneity, and described cooling fluid 5 is along being perpendicular to gain media 1 The transmission of direction, length and width face 106, the used heat in gain media 1 is taken away from the face of growing tall 104, there is efficient dissipating Heat energy power, meanwhile, laser field is parallel with temperature gradient field, reduce gain media 1 thermal distoftion to laser wave before Impact, it is ensured that beam quality.

Embodiment two:

As Figure 1-5, described gain media 1 is set to laminated structure, and along the biography of pump light 4 inside it Defeated direction is set to gradient doping structure, it is ensured that the gain in gain media 1 is uniformly distributed, and this structure is very Being applicable to quasi-three-level gain media or the gain media of low absorption coefficient, described gain media 1 is from inside to outside Include that center 101, transition zone 102 and covering 103, described center 101 and covering 103 are disposed as successively Gradient doping structure, the active ions of the internal doping in described center 101 are Nd³⁺Or Yb³⁺, thus ensure that Pump light 4 is absorbed in center 101, and the active ions of the internal corresponding doping of described covering 103 are Sm³⁺Or Cr⁴⁺, pump light 4 is absorbed few by it, high to laser 3 spontaneous radiation efficiency of light absorption, it is suppressed that gain media 1 Horizontal self-oscillation, it is ensured that the high-gain ability of gain media 1, described transition zone 102 is set to undoped Medium, effectively reduces the thermograde of center 101 surrounding, reduces moving back caused by thermic stress birfringence Loss partially, and along the transmission direction of pump light 4, the doping content of described center 101 excited inside ion is two Holding the Long-term change trend that low centre is high, the doping content of described covering 103 excited inside ion is linearly or non-linear Long-term change trend, described gain media 1 is set to mix the phosphate glass of Nd, it is possible to for crystal or pottery Yb:YAG、Yb:CaF₂、Nd:CaF₂Or Nd:YAG.

The height of described coupling device 203 is equal with the height of center 101, and described pumping source 2 sets at least to One, can further improve the gain ability of laser gain chip, adjacent coupled by increasing pumping source 2 quantity Device 203 arranges along its width, and the overall width of coupling device 203 is not more than the width of center 101. The present embodiment by 2 coupling devices 203 the most side by side, improves pump power density, single coupling Locking device 203 is longitudinally formed by multifiber 204, and the width of single coupling device 203 is about 1mm.By Output light field in each coupling device 203 is distributed identical, therefore, it is possible to while improving pump power, Ensure good pumping homogeneity.

Embodiment three:

As a shown in Figure 6, a kind of laser module, comprise above-mentioned laser gain chip, described laser gain Chip is multiple along the cascade of Laser Transmission direction, can realize power expansion, and each gain media 1 has independent It is obtained in that identical small-signal gain in pumping source 2, and each gain media 1, and gain profiles is uniform, The pump energy and the heat production density that absorb have identical distribution, during power expansion, are not required to consider Other factors affect, and simple operation, meanwhile, the spacing of adjacent laser chip gain is millimeter magnitude, preferably For 0.5-5mm, compact conformation, take up room little.

It is internal that described laser module is arranged on laser module shell 6, and described laser module shell 6 includes window 61 With housing 62, window 61 being coated with laser anti-reflection film, described laser is incident to laser module shell 6 through window 61 Inside, described housing 62 is set to light tight structure.Described laser module also includes fluid circulator 7 and fluid Pipeline 8, described fluid circulator 7 is connected with housing 62 by fluid line 8, and described cooling fluid 5 is by fluid hose Road 8 enters in laser module shell 6, flows through, taken away by heat between adjacent gain media 1.

Described cooling fluid 5 can use cooling liquid, and such as carbon tetrachloride, Carbon bisulfide, heavy water etc., gain is situated between The Maximum pumping density that matter 1 the can bear boiling point with cooling liquid, the break limit phase of gain media 1 Closing, under the conditions of this, the spacing of adjacent laser chip gain is 0.5-3mm.Described cooling fluid 5 can use cold But gas, such as helium etc., under the conditions of this, the spacing of adjacent laser chip gain is 2-5mm.

Embodiment four:

As it is shown in fig. 7, a kind of single laser cavity power amplifier, comprise above-mentioned laser gain chip, described sharp Gain of light chip transmits direction along laser 3 and cascades multiple composition laser modules, the spacing of adjacent laser chip gain For millimeter magnitude, preferably 0.5-5mm, along the transmission direction of laser 3, described amplifier includes same successively The lasing light emitter 9 of optical axis setting, beam-expanding system 1, polaroid 12,45 ° of quartzy rotors of one 11,45 ° of faraday 13, polaroid 2 14, front cavity mirror 1, reflecting mirror 1, reflecting mirror 2 17, laser module, Image relaying system Unification 18 and Effect of Back-Cavity Mirror 1, described front cavity mirror 1, Effect of Back-Cavity Mirror 1 are total reflective mirror, described Effect of Back-Cavity Mirror one Quarter wave plate 1 it is provided with at 20.

Lasing light emitter 9 output laser 3, successively through beam-expanding system 1, one 11,45 ° of faraday 12 of polaroid, After 45 ° of quartzy rotors 13, polaroid 2 14, reflecting mirror 1, reflecting mirrors 2 17, in injection laser module also Pass perpendicularly through gain media 1, image in Effect of Back-Cavity Mirror 1 through Image relaying system 1, quarter wave plate 1, Laser 3 realizes a Cheng Fang great, Effect of Back-Cavity Mirror 1 after the laser 3 returned sequentially passes through each element, through polaroid 2 14 reflex to front cavity mirror 1, and laser 3 realizes the second Cheng Fang great, front cavity mirror 1 laser 3 returned is again Inject laser module, it is achieved three journeys, quadruple pass amplify, and repeat no more, after export through polaroid 1.

As shown in Figure 8, a kind of bidifly optical cavity power amplifier, comprise above-mentioned a kind of laser gain chip, institute State laser gain chip to transmit direction cascade along laser 3 and multiple separately constitute laser module 1 and laser module two 35, the spacing of the adjacent laser chip gain being in same laser module is millimeter magnitude, is preferably 0.5-5mm。

Along the transmission direction of laser 3, described amplifier includes lasing light emitter 9, the reflection that same optical axis arranges successively Mirror 3 21, beam-expanding system 2 22, reflecting mirror 4 23, polaroid 3 24, Image relaying system 2 25, quarter wave plate 2 26,3 27,90 ° of polarization apparatus rotors 28 of Image relaying system, Image relaying system 4 29, reflecting mirror 5 30, swash Optical assembly 1, laser module 2 35, described reflecting mirror 3 21 and beam-expanding system 2 22 are set to off-axis out of focus knot Structure, is provided with shielding system and reflecting mirror 6 33 at described polaroid 3 24, in time suppressing pumping from exciting Swinging, it is ensured that the gain ability of system, described shielding system includes electrooptical switching 31, polaroid 4 32 successively.

The laser 3 of described lasing light emitter 9 output, the vertical paper of laser 3 polarization state, it is reflected mirror 3 21 successively, expands After beam system 2 22, reflecting mirror 4 23, polaroid 3 24, Image relaying system 2 25, quarter wave plate 2 26, with Circular polarization state injects in laser module 1, after 3 27,90 ° of polarization apparatus rotors 28 of Image relaying system, described 90 ° of polarization apparatus rotors 28 are used for compensating hot depolarization, are injected in laser module 2 35, through Image relaying system four 29, after reflecting mirror 5 30, again by laser module 2 35, laser module 1, after crossing quarter wave plate 2 26, The polarization state of laser 3 is transformed into the polarization state of parallel paper by initial vertical paper polarization, is transmitted through polarization Sheet 3 24, comes and goes through shielding system, reflecting mirror 6 33, and the polarization state of laser 3 keeps constant, and reflection light is again Secondary through polaroid 3 24, laser 3 transmits with the polarization state of parallel paper, and transmitting procedure repeats no more, laser 3 After laser module 2 35, laser module 1, when crossing quarter wave plate 2 26, the polarization state of laser 3 returns to hang down In straight paper, reflect from polaroid 3 24, be reflected mirror 4 23, beam-expanding system 2 22 output.

Described amplifier is applicable to impulse type bidifly optical cavity power amplifier, after removing shielding system, the suitableeest For continuous bidifly optical cavity power amplifier.

As it is shown in figure 9, a kind of agitator, include front cavity mirror 2 36, above-mentioned a kind of laser gain chip successively With Effect of Back-Cavity Mirror 2 37, it is multiple that described laser gain chip transmits direction cascade along laser 3, adjacent laser gain core The spacing of sheet is millimeter magnitude, preferably 0.5-5mm, and described front cavity mirror 2 36 is set to total reflective mirror, described before Chamber mirror 2 36 is it can also be provided that distorting lens, and to compensate wavefront distortion, it is anti-that described Effect of Back-Cavity Mirror 2 37 is set to part Penetrate mirror.

Embodiment five:

As Figure 1-4, the present embodiment repeats no more, except for the difference that with the identical part of embodiment one, two:

Described gain media 1 is set to Nd:YAG, its a size of 120mm × 120mm × 10mm, center 101 bores are 100mm × 100mm, and transition zone 102 is pure YAG, and its overall width is 10mm, covering The active ions of 103 internal doping are Sm³⁺, its overall width is 10mm, and described laser 3 is along being perpendicular to the face of growing tall 104 direction transmission, described pump light 4 is along being perpendicular to the transmission of wide high surface 105 direction, and described cooling fluid 5 is along vertically Transmitting in direction, length and width face 106, described cooling fluid 5 is set to carbon tetrachloride liquid.

Along the transmission direction of pump light 4, the internal Nd in described center 101³⁺Doping content linearly trend become Change, the internal Sm of described covering 103³⁺Doping content linearly Long-term change trend, pump light 4 power density is 330W/cm², when absorption efficiency is 95%, Nd³⁺The concentration distribution of ion linear doping divides with small-signal gain Cloth relation, as shown in Figure 10 (a), in figure, small signal gain coefficient transmits direction along pump light 4 is that center is low by two The distribution that limit is high, gain profiles is uneven, is unfavorable for obtaining uniform laser near-field.

Along the transmission direction of pump light 4, the internal Nd in described center 101³⁺Doping content be two ends low in the middle of high Long-term change trend, the internal Sm of described covering 103³⁺Doping content linearly Long-term change trend, described Nd³⁺Mix Miscellaneous concentration is:

By

Draw:

$n_d=\frac{g_0}{{\mathrm{\σ}}_{em}}\frac{1+{\mathrm{CI}}_{Ps}}{B+{\mathrm{AI}}_{Ps}}=\frac{g_0}{{\mathrm{\σ}}_{em}}\frac{I_{Ps}^{+}+C\[{\left(I_{Ps}^{+}\right)}^2+(1-{\mathrm{\η}}_P){\left(I_{Ps,in}^{+}\right)}^2\]}{{\mathrm{BI}}_{Ps}^{+}+A\[{\left(I_{Ps}^{+}\right)}^2+(1-{\mathrm{\η}}_P){\left(I_{Ps,in}^{+}\right)}^2\]},$

Wherein, n_dRepresent the doping concentration distribution of center 101 excited inside ion, η_PRepresent that pump light 4 absorbs Efficiency, g₀Represent small-signal gain, I_Ps,inRepresent the pumping light intensity that gain media 1 both sides are total, I⁺ _Ps,inRepresent gain The pumping light intensity of medium 1 one side, and meetI_PsRepresent the local pumping light intensity in gain media, I⁺ _PsRepresent that single-side pumping light transmits direction distribution in gain media along it, described light intensity be pumping light intensity with The ratio of pumping saturation light intensity, with the central point of center 101 as zero, x represents and transmits along pump light 4 The position in direction, W represents that the length in direction, σ are transmitted along pump light 4 in center 101_absWith σ_emRepresent pump respectively Pu light 4 absorption cross-section and Laser emission cross section, A, B, C represent the hot population characteristic of dopant ion.

Under room temperature, Nd³⁺Parameter is: σ_abs=6.7 × 10^-20cm², σ_em=28 × 10^-20cm², A=C=η_Q, B=0, η_Q=1, wherein, η_QFor fluorescence efficiency, pump light 4 power density is 330W/cm², η_P=95%, Nd³⁺From Concentration distribution and the small signal gain distribution relation of sub-gradient doping, as shown in Figure 10 (b), along pumping in figure Light 4 transmits direction and uses gradient doping, and concentration is distributed in class gaussian shaped profile, and the gain in gain media 1 divides Cloth is uniform, and therefore, described laser gain chip is applicable to four-level system.

Embodiment six:

As Figure 1-4, the part that the present embodiment is identical with embodiment five repeats no more, except for the difference that:

Described gain media 1 is set to Yb:YAG, and the active ions of the internal doping of covering 103 are Cr⁴⁺, described Cooling fluid 5 is set to helium.

Along the transmission direction of pump light 4, the internal Yb in described center 101³⁺Doping content linearly trend become Change, the internal Cr of described covering 103⁴⁺Doping content be nonlinear trend change, pump light 4 power density is 9.4kW/cm², when absorption efficiency is 95%, Yb³⁺The concentration distribution of ion linear doping divides with small-signal gain Cloth relation, as shown in Figure 11 (a), in figure, small signal gain coefficient transmits direction along pump light 4 is that center is low by two The distribution that limit is high, gain profiles is uneven, is unfavorable for obtaining uniform laser near-field.

Along the transmission direction of pump light 4, the internal Yb in described center 101³⁺Doping content be two ends low in Between high Long-term change trend, the internal Cr of described covering 103⁴⁺Doping content be nonlinear trend change, at 200K Time, Yb³⁺Parameter is: σ_abs=1.1 × 10^-20cm², σ_em=4.4 × 10^-20cm², f₀₁=0.8749, f₀₃=0.0464, f₁₁=0.7667, f₁₂=0.1846, wherein, f_ijRepresent pumping energy The hot population ratio of level its residing multiplet shared with laser levels, pump light 4 power density is 9.4kW/cm², η_P=95%, Yb³⁺Concentration distribution and the small signal gain distribution relation of ion gradient doping, as Shown in Figure 11 (b), transmitting direction along pump light 4 and use gradient doping in figure, concentration is distributed in class Gaussian Distribution, the gain profiles in gain media 1 is uniform, and therefore, described laser gain chip is applicable to accurate three energy Level system.

Below the present invention is described in detail, the above, only the preferred embodiments of the invention, When not limiting the scope of the present invention, the most all made impartial change according to the application scope and modified, all should be still Belong in covering scope of the present invention.

Claims (9)

1. a laser gain chip, including lasing light emitter, gain media, pumping source and cooling fluid, described Pumping source includes diode array and the coupling device being connected, it is characterised in that: described lasing light emitter, coupling Device and the not ipsilateral setting of cooling fluid respectively corresponding gain media, and described cooling fluid, pump light, The transmission direction perpendicular quadrature of laser, inside described gain media, the transmission direction along pump light is set to gradually Varied doping structure.

A kind of laser gain chip the most according to claim 1, it is characterised in that: described gain media Being set to laminated structure, it includes center, transition zone and covering the most successively, described center and Covering is disposed as gradient doping structure, and described transition zone is set to undoped medium, inside described center The active ions of doping are Nd³⁺Or Yb³⁺, the active ions of the internal corresponding doping of described covering are Sm³⁺Or Cr⁴⁺, Along the transmission direction of pump light, the doping content of described center excited inside ion is that low centre, two ends is high Long-term change trend.

A kind of laser gain chip the most according to claim 2, it is characterised in that: in described center The doping content of portion's active ions is:

By

Draw:

$n_d=\frac{g_0}{{\mathrm{\σ}}_{em}}\frac{1+{\mathrm{CI}}_{Ps}}{B+{\mathrm{AI}}_{Ps}}=\frac{g_0}{{\mathrm{\σ}}_{em}}\frac{I_{Ps}^{+}+C\[{\left(I_{Ps}^{+}\right)}^2+(1-{\mathrm{\η}}_P){\left(I_{Ps,in}^{+}\right)}^2\]}{{\mathrm{BI}}_{Ps}^{+}+A\[{\left(I_{Ps}^{+}\right)}^2+(1-{\mathrm{\η}}_P){\left(I_{Ps,in}^{+}\right)}^2\]},$

Wherein, n_dRepresent the doping concentration distribution of center excited inside ion, η_PRepresent pump light absorption efficiency, g₀Represent small-signal gain, I_Ps,inRepresent the pumping light intensity that gain media both sides are total, I⁺ _Ps,inRepresent gain media list The pumping light intensity of side, and meetI_PsRepresent the local pumping light intensity in gain media, I⁺ _PsTable Showing that single-side pumping light transmits direction distribution in gain media along it, described light intensity is pumping light intensity and pumping The ratio of saturated light intensity, with the central point of center as zero, x represents the position along pumping optical transmission direction Putting, W represents the center length along pumping optical transmission direction, σ_absWith σ_emRepresent Pumping light absorption cross section respectively With Laser emission cross section, A, B, C represent the hot population characteristic of dopant ion.

A kind of laser gain chip the most according to claim 1, it is characterised in that: described diode battle array Row include symmetrically arranged diode array one and diode array two centered by gain media, described two poles Pipe array one and diode array two are connected with gain media by coupling device respectively, and described coupling device sets Being set to banded structure, it is made up of multifiber, and the height of described coupling device is equal with the height of center, Described pumping source sets at least to one, and adjacent coupled device arranges along its width, and coupling device Overall width is not more than the width of center.

A kind of laser gain chip the most according to claim 1, it is characterised in that: described gain media Being coated with laser anti-reflection film on the side corresponding with lasing light emitter, described laser passes along the direction being perpendicular to described side Defeated, and through gain media, described coupling device and gain media are set to plane-plane contact, and described gain is situated between Being coated with pump light anti-reflection film with coupling device on the side that matter contacts, described pump light is on the internal edge of gain media Optic path in a zigzag.

6. a laser module, it is characterised in that: comprise the arbitrary described a kind of laser gain of claim 1-5 Chip, described laser gain chip is multiple along the cascade of Laser Transmission direction, the spacing of adjacent laser chip gain For millimeter magnitude.

7. a single laser cavity power amplifier, it is characterised in that: comprise claim 1-5 arbitrary described one Planting laser gain chip, described laser gain chip cascades multiple composition laser modules along Laser Transmission direction, The spacing of adjacent laser chip gain is millimeter magnitude, arranges front cavity mirror one and Effect of Back-Cavity Mirror at described laser module One, described front cavity mirror one, Effect of Back-Cavity Mirror one are total reflective mirror, are provided with quarter wave plate one at described Effect of Back-Cavity Mirror one.

8. a bidifly optical cavity power amplifier, it is characterised in that: comprise claim 1-5 arbitrary described one Planting laser gain chip, described laser gain chip separately constitutes laser group along the cascade of Laser Transmission direction is multiple Part one and laser module two, the spacing of the adjacent laser chip gain being in same laser module is millimeter amount Level, is provided with 90 ° of polarization apparatus rotors between described laser module one and laser module two.

9. an agitator, it is characterised in that: include that front cavity mirror two, claim 1-5 are arbitrary described successively A kind of laser gain chip and Effect of Back-Cavity Mirror two, described laser gain chip is multiple along the cascade of Laser Transmission direction, The spacing of adjacent laser chip gain is millimeter magnitude, and described front cavity mirror two is set to total reflective mirror, described back cavity Mirror two is set to partially reflecting mirror.