CN101068065A - Ultra large power two-dimensional semiconductor lock phase array stable oscillation mode technique - Google Patents

Abstract

This invention provides a double-path adaptive sensing compensated mode-stabilizing system technology, which puts forward a method for setting up two paths of parallel adaptive compensated mode-stabilizing systems with exchangeable positions including setting up a subsystem related to CCD1for testing change of an outer cavity and a subsystem related to CCD2 for compensating the change of the outer cavity, in which, each path of the subsystems for testing the change test the He-Ne laser wavefront slope related parameters reflected by the outer cavity mirror and compute the shape-change volume of the outer cavity and necessary compensation volume, then the subsystems for compensation coordinated to each other compensate a directional change of the outer cavity, and a double-path mode-stabilizing system carries out cooperated optimized compensated operation on the basis of testing one direction of shape-change parameter by each path of adaptive sensing compensated mode-stabilizing system to counteract the change of position of super-mode optical image aroused by beta-disturbance.

Description

A kind of ultra large power two-dimensional semiconductor lock phase array stable oscillation mode technique

Technical field

The invention belongs to exocoel distortion measurement technology and the compensation technique of stablizing ultra-high power semiconductor lock phase array concussion pattern, after relating to the external cavity mirror selection lowest order super-mode concussion of ultra-high power semiconductor array by the adaptive angle of deflection, residual heat effect etc. caused relate to the automatic measurement and the compensation compensation way method of exocoel deformation and avoid exocoel deformation to cause non-lowest order super-mode starting of oscillation.

Background technology

Semi-conductor array quantum efficiency height, the output wavelength scope contains 570nm to 1600nm, working life can reach millions of hours, the lamination array can provide the output of ultra high power laser, such as industry, a lot of fields such as medical science have boundless and good prospects for application, but because that each luminescence unit of semi-conductor array of free-running operation sends is only incoherent, its output quality is relatively poor, particularly the angle of divergence of slow axis multimode output is big, spectral width, disturbing, chromatic dispersion, aspect characteristic extreme differences such as directivity, both can't focus on small size by optical system, can't realize long-distance transmissions again, seriously hinder it in machining, surface treatment, the high power density pumping, obtain in the fields such as space high speed optical communication effectively to use.Thereby, take the phase-locked measure in space to make each unit run on identical wavelength and make and have fixing phase difference between them, it is most important just to become.

Realize that the relevant operation method in each unit comprises inner couplings and coupled outside.Inner couplings distributes, constructs suitable measures such as active layer, substrate and cover layer by control refractive index, gain region makes the position obtain locking mutually, but the corresponding luminescence unit width of this kind mechanism has limited the power that semi-conductor array can be exported greatly, in addition, its corresponding systematic jitters can increasing with the increase of drive current and increase along with luminescence unit.Coupled outside is by realizing phase-locked output in outside phase conjugate lens feedback injection locking technique, principal and subordinate's laser injection locking technique, the external cavity mirror technology of adopting of semi-conductor array.

Reach hundreds of microns high power semiconductor laser array for adjacent luminescence unit distance, suitable especially employing is phase-locked based on the exocoel coupling of mode coupling theory and Talbot chamber theory, the corresponding power coupling mainly occurs between the next-door neighbour unit, the coupling of non-adjacent unit can be ignored, and corresponding system is simple in structure and effect is good.

Utilize the work centre wavelength to be λ, the slow axis array cycle is d, and the chamber is long to be L _C=d ²/ 2 λ, the external cavity mirror normal direction can successfully lock the high power semiconductor laser array phase place perpendicular to the 1/4Talbot external cavity mirror technology of slow axis, but corresponding far-field distribution is the bivalve structure, indicates that corresponding concussion pattern is high-order super model; According to mark Talbot chamber field distribution rule, shake in lowest order super-mode for making system, to obtain far-field distribution is the single-lobe structure, splendid output near diffraction limit, must be with this 1/4Talbot external cavity mirror at slow-axis direction deflection certain angle suitably, this is the mode that two-dimensional semiconductor lamination array adopts the concussion of exocoel choice of technology lowest order super-mode, successfully obtain Project Realization, yet, be applied to the ultra large power two-dimensional semiconductor array when phase-locked in this technology, after the external cavity mirror of the adaptive angle that tilts makes array select the lowest order super-mode concussion, though cooling subsystem can ensure the array continuous firing, but the residual heat effect can make that still exocoel deformation constantly aggravates, add platform vibrations etc., cause high-order super model concussion.Therefore, must take steady mould measure to the ultra large power two-dimensional semiconductor array, so that array can stably shake in lowest order super-mode, the outputting high quality laser beam, for this reason, the present invention has provided a kind of ultra large power two-dimensional semiconductor lock phase array stable oscillation mode technique.

Summary of the invention

The technical problem that the present invention is directed to is described: when semi-conductor array adopts 1/4Talbot external cavity mirror technology phase-locked, after its external cavity mirror is by the location deflection β=λ/2d perpendicular to luminescence unit, the high-order super model light reflection that external cavity mirror is sent luminescence unit also images between luminescence unit, thereby, cavity loss is very big, and simultaneously, the lowest order super-mode light reflection that luminescence unit is sent also images in the luminescence unit, thereby array will select lowest order super-mode concussion, and array and corresponding light field distribution are as shown in Figure 1.But, for the ultra large power two-dimensional semiconductor array, when this technology of employing is phase-locked, though the cooling subsystem of array can ensure the array continuous firing, along with the increase of array power output,, will cause the β drift because residual heat effect etc. act on external cavity mirror, for Guang Fa district slow axis width is any one luminescence unit of S, when the β drift surpasses S λ/2d ²The time, the lowest order super-mode reverberation that surpasses half will image between the luminescence unit, cause high-order super model to be dominant; When the β drift surpasses ((d-S) λ)/2d ²The time, the high-order super model reverberation that surpasses half will image in the lightening hole, also will cause high-order super model to be dominant, and shake in lowest order super-mode for ensureing array invariablely, must compensate the β drift that external cavity mirror deformation causes in time.

The technical problem solution that the present invention is directed to: the external cavity mirror deformation of adopting the compensation of two-path adaptive sensing to cause by residual heat effect etc., collaborative by each unit of subsystem of measuring exocoel deformation, the He-Ne laser beam-wave front slope relevant parameter that measurement is reflected by external cavity mirror, calculate exocoel deformation quantity and required compensation rate, collaborative by each unit of subsystem of compensation exocoel deformation again, the deformation of compensation exocoel, the change of the super model photoimaging position that counteracting β disturbance causes.Fig. 2 is ultra large power two-dimensional semiconductor lock phase array two-path adaptive sensing bucking-out system structural design, constitutes element, reaches the operation schematic diagram, its exocoel is a replicated structures, corresponding external cavity mirror normal direction and array luminescence unit normal direction have certain angle, the transmission length that the laser that each luminescence unit sends is sent to external cavity mirror is long for the 1/4Talbot chamber, i.e. L _C=d ²/ 2 λ, external cavity mirror the slow axis counterparty to deflection angle β=λ/2d; Increase along with array output lowest order super-mode laser power, the residual heat effect makes β that the two-way drift of near symmetrical take place, the property of the present invention is directed to ground adopts the compensation of two-path adaptive sensing, rely on distortion measurement relevant and compensation equipment and measure and compensation equipment with the R1.2 related deformation with R1.1, each measures drift value of a direction of β in good time, and respectively timely compensation it.

The present invention adopts the He-Ne laser as the active sensing light source, expand bundle through the coupling beam expanding lens, reflect by spectroscope again, project on the 1/4Talbot external cavity mirror reflecting surface of inclination β, thereafter, He-Ne laser beam through the external cavity mirror reflection will penetrate spectroscope, toward mirror R1.1 and R1.2, after speculum 3 reflections, that part of He-Ne laser beam of corresponding R1.1 will be regulated through zoom optics 1, with coupling microlens array 1, thereby, each lenticule can image in corresponding incident beam the last pel array of CCD1, i.e. the last fixed area of CCD1, corresponding facula mass center, the corresponding wavefront slope in sub-aperture, and the wavefront slope maximum of corresponding CCD1, the wavefront slope average of corresponding CCD1, driving relevant obtaining by processor 1 of the required driving voltage value of piezoelectricity compensator finishes, and then cooperate corresponding D/A, corresponding high drive module, the piezoelectricity compensator PZT that drives R1.1 expands, and the deformation of a direction of external cavity mirror is compensated; Simultaneously, remaining He-Ne laser beam, be that part of of corresponding R1.2, to regulate through zoom optics 2, with coupling microlens array 2, thereby each lenticule can image in corresponding incident beam the last pel array of CCD2, its facula mass center, the corresponding wavefront slope in sub-aperture, and the wavefront slope maximum of corresponding CCD2, the wavefront slope average of corresponding CCD2, driving relevant obtaining by respective processor 2 of the required driving voltage value of piezoelectricity compensator finishes, and then cooperate corresponding D/A, corresponding high drive module, the piezoelectricity compensator PZT that drives R1.2 expands, and the deformation of external cavity mirror another one direction is compensated.Deformation has uncertainty at external cavity mirror, the bucking-out system model has uncertainty, piezoelectricity compensation actuator exists sluggishness and nonlinear effect, the combination model perturbation, two-way measurement subsystem and Compensation subsystem are collaborative, control is optimized, satisfying the relevant parameter matching sensing of measurement subsystem light source with Compensation subsystem, the adaptive compensator amplitude characteristic of controller, frequency characteristic, measurement subsystem and Compensation subsystem are possessed under enough resolution and the control precision condition carry out system design, obtain enough measurement and compensation ability, more preferably to measuring and compensating operation.

Description of drawings

Fig. 1 is phase-locked semi-conductor array of 1/4Talbot external cavity mirror technology and the corresponding light field distribution schematic diagram of inclination β, β=λ/2d;

Fig. 2 is a ultra large power two-dimensional semiconductor lock phase array two-path adaptive sensing bucking-out system schematic diagram;

Fig. 3 optimizes FB(flow block), S for phase-locked system ₀Corresponding array is selected the feedback light optimal imaging position of lowest order super-mode, W _S0Be respective performances weighting, S ₁Corresponding array is selected the feedback light actual imaging position of super model, the corresponding departure of δ e, W _eBe the respective performances weighting, D (S) is the detector transfer function, and C (S) is the controller transfer function, the corresponding model perturbation of ρ, W _ωBe the perturbation weighting function of uncertain region that must covering system, M (S) be actuator's transfer function, the disturbance of Δ correspondence, W _ΔBe disturbance input weighting function.

Fig. 4 is not for before adopting the technology that the present invention provides, rely on the phase-locked ultra large power two-dimensional semiconductor array of 1/4Talbot external cavity mirror technology of inclination λ/2d, after output a period of time, typical output field distributes, as seen, exocoel deformation has caused the variation of concussion pattern.Fig. 5 for the technology that adopts the present invention and provide after, rely on the phase-locked ultra large power two-dimensional semiconductor array of 1/4Talbot external cavity mirror technology of inclination λ/2d, typical output field distributes, as seen, exocoel deformation has obtained good compensation, and array stable ground shakes in lowest order super-mode.

Specify content of the present invention below by example:

Embodiment

He-Ne laser beam from the active sensing light source, expand bundle, spectroscope reflection through the coupling beam expanding lens, project the 1/4Talbot external cavity mirror, after being reflected, penetrate spectroscope again, and after speculum R1.1 and R1.2, speculum 3 reflections, the He-Ne laser beam of corresponding R1.1 images in CCD1 through zoom optics 1, microlens array 1, the He-Ne laser beam of corresponding R1.2 images in CCD2 through zoom optics 2, microlens array 2, the facula mass center (x in corresponding norator aperture _C, y _C), can pass through

$x_C=\frac{\underset{i,j}{\overset{M,N}{\mathrm{\Σ}}}{x}_{\mathrm{ij}}{I}_{\mathrm{ij}}}{\underset{i,j}{\overset{M,N}{\mathrm{\Σ}}}{I}_{\mathrm{ij}}},$ $y_C=\frac{\underset{i,j}{\overset{M,N}{\mathrm{\Σ}}}{y}_{\mathrm{ij}}{I}_{\mathrm{ij}}}{\underset{i,j}{\overset{M,N}{\mathrm{\Σ}}}{I}_{\mathrm{ij}}}$

Calculate, M is the line number in the pel array formula in corresponding this sub-aperture, and N is the columns in the pel array formula, x _IjBe (i, x coordinate j), the y of pixel in the pel array _IjBe pixel (i, Y coordinate j), I _IjRespective pixel (i, output intensity value j).If when deformation does not take place external cavity mirror, a facula mass center is (x _Ck0, y _Ck0), so, after the external cavity mirror generation deformation, certain deviation will take place and become (x in corresponding facula mass center _Ck1, y _Ck1), if this lenticular focal length is f, then corresponding hot spot wavefront slope is

S _xk＝(x _Ck1-x _Ck0)/f，S _yk＝(y _Ck1-y _Ck0)/f；

Lenticule is add up to the microlens array 1 of Ω, the corresponding wavefront slope in each sub-aperture

S _x＝[S _x1，S _x2，S _x3，...，S _xΩ]，S _y＝[S _y1，S _y2，S _y3，...，S _yΩ]；

Maximum

S _x(MAX)＝maxS _xk＝max[S _x1，S _x2，S _x3，..，S _xΩ]，

S _y(MAX)＝maxS _yk＝max[S _x1，S _x2，S _x3，...，S _xΩ]；

All believe

${\stackrel{\‾}{S}}_x=\frac{1}{\mathrm{\Ω}}\underset{k=1}{\overset{\mathrm{\Ω}}{\mathrm{\Σ}}}{S}_{\mathrm{xk}},$ ${\stackrel{\‾}{S}}_y=\frac{1}{\mathrm{\Ω}}\underset{k=1}{\overset{\mathrm{\Ω}}{\mathrm{\Σ}}}{S}_{\mathrm{yk}}$

The required driving voltage value of drive pressure electronic compensating device is

$V_C=G*S=\left[G_x{G}_y\right]*{\left[S_x{S}_y\right]}^T$

$=\underset{k=1}{\overset{\mathrm{\Ω}}{\mathrm{\Σ}}}[(g_{\mathrm{xk}}-G_{x}E/\mathrm{\Ω})\widehat{S_{\mathrm{xk}}}+(g_{\mathrm{yk}}-G_{y}E/\mathrm{\Ω})\widehat{S_{\mathrm{yk}}}],$

In the formula

E＝[1，1，1，...，1] ^T

$\widehat{S_{\mathrm{xk}}}={\mathrm{\ω}}_x*S_{\mathrm{xk}}+{\stackrel{\‾}{\mathrm{\ω}}}_{\mathrm{xk}}*{\stackrel{\‾}{S}}_x+{\mathrm{\ω}}_{\mathrm{xk}}*S_{x\left(\mathrm{MAX}\right)},$

$\widehat{S_{\mathrm{yk}}}={\mathrm{\ω}}_y*S_{\mathrm{yk}}+{\stackrel{\‾}{\mathrm{\ω}}}_{\mathrm{yk}}*{\stackrel{\‾}{S}}_y+{\mathrm{\ω}}_{\mathrm{yk}}*S_{y\left(\mathrm{MAX}\right)};$

ω _x, ω _Xk, ω _XkBe

Each performance weighted value, ω _y, ω _Yk, ω _YkBe

Each performance weighted value, with both direction deformation and compensate crosslinked relevantly, be importance of system optimization design; g _XkBe G _xColumn vector, g _YkBe G _xRow vector, can calculate by measurement in advance and be stored in the processor, for calculating V in real time _CIn time, call, and sets initial value V ⁰=[0,0,0 .., 0] ^T, the corresponding formula that iterates is

${V_C}^k={V_C}^{k-1}+(g_{\mathrm{xk}}-G_{x}E/\mathrm{\Ω})\widehat{S_{\mathrm{xk}}}+(g_{\mathrm{yk}}-G_{y}E/\mathrm{\Ω})\widehat{S_{\mathrm{yk}}};$

In view of the above, associative processor cooperates D/A, high drive module in good time after calculating driving voltage, the deformation of compensation external cavity mirror.The processing of the measurement of corresponding that direction deformation of R1.1 of external cavity mirror, computing, compensation is by R1.1, CCD1, processor 1, D/A, corresponding high drive module, the collaborative complete operation of corresponding piezoelectricity compensator; Simultaneously, another direction of external cavity mirror, i.e. the processing of the measurement of that direction deformation of corresponding R1.2, computing, compensation is by R1.2, CCD2, processor 2, D/A, corresponding high drive module, the collaborative complete operation of corresponding piezoelectricity compensator.External cavity mirror deformation has uncertainty, the bucking-out system model has uncertainty, piezoelectricity compensation actuator exists sluggishness and nonlinear effect, for obtaining that the high-performance of ultra large power two-dimensional semiconductor array external cavity mirror deformation is measured and compensation, must combination model perturbation the two-path adaptive sensing compensated steady modular system control be optimized, Fig. 3 is the related procedure block diagram, low order time controller is convenient to Project Realization, under the prerequisite that guarantees designing requirement, during optimization, adopted the weighting function of low order to satisfy the systematic function requirement as much as possible.At exocoel distortion measurement and the relevant parameter matching sensing of Compensation subsystem light source, the adaptive compensator amplitude characteristic of controller, frequency characteristic, make exocoel distortion measurement and Compensation subsystem possess enough resolution and control precision, carry out the two-path adaptive sensing under the control bandwidth condition and compensate steady modular system optimal control design satisfying, obtained enough measurements and compensation ability.

Fig. 4 is not for before adopting the technology that the present invention provides, rely on the phase-locked ultra large power two-dimensional semiconductor array of 1/4Talbot external cavity mirror technology of inclination λ/2d, after output a period of time, typical output field distributes, as seen, exocoel deformation has caused the variation of concussion pattern; Fig. 5 for the technology that adopts the present invention and provide after, rely on the phase-locked ultra large power two-dimensional semiconductor array of 1/4Talbot external cavity mirror technology of inclination λ/2d, typical output field distributes, as seen, exocoel deformation has obtained good compensation, and array stable ground shakes in lowest order super-mode.

Beneficial effect of the present invention: the two-path adaptive sensing compensates steady modular system by two-way measurement subsystem and Compensation subsystem combined measurement and compensation, can be servo well in the 1/4Talbot of inclination λ/2d external cavity mirror technology, overcome external cavity mirror deformation and give the phase-locked influence that brings of ultra large power two-dimensional semiconductor array, array can stably be shaken in lowest order super-mode.

Claims (5)

1, serves the stable two-path adaptive sensing of homophase mould concussion of selecting of ultra-high power semiconductor array and compensate steady modular system, comprise that making up the two-path adaptive sensing based on the replicated structures exocoel compensates steady modular system, each road adaptive sensing compensates steady modular system and comprises the subsystem of measuring exocoel deformation, the subsystem of compensation exocoel deformation.It is characterized in that: it is that the adaptive sensing of two parallel connections compensates steady modular system that described two-path adaptive sensing compensates steady modular system, the subsystem of measuring exocoel deformation is positioned at outside the speculum 2, the subsystem of compensation exocoel deformation is positioned in the middle of spectroscope and the speculum 2, and two-way is respectively proofreaied and correct the deformation of a direction of external cavity mirror concurrently.

2, two-path adaptive sensing according to claim 1 compensates steady modular system, the subsystem of measuring exocoel deformation comprises active sensing light source, coupling beam expanding lens, spectroscope, the 1/4Talbot external cavity mirror of inclination β, speculum R2.1, speculum R2.2, speculum 3, zoom optics, microlens array, CCD, processor, calculate deformation quantity and finished by processor with the calculating compensation rate, the subsystem of compensation exocoel deformation comprises D/A, high drive module, piezoelectricity compensator.It is characterized in that: collaborative by each unit of subsystem of measuring exocoel deformation, the He-Ne laser beam-wave front slope relevant parameter that measurement is reflected by external cavity mirror, calculate exocoel deformation quantity and required compensation rate, collaborative by each unit of subsystem of compensation exocoel deformation again, the deformation of compensation exocoel, the change of the super model photoimaging position that counteracting β disturbance causes.

3, two-path adaptive sensing according to claim 1 compensates steady modular system, it is characterized in that: the deformation of described measurement exocoel, calculating deformation quantity and calculating compensation rate, the deformation of compensation exocoel launch to deflection angle β the slow axis counterparty at influencing external cavity mirror, serve as main expansion with a coordinate components.

4, two-path adaptive sensing according to claim 1 compensates steady modular system, it is characterized in that: the system of the measurement exocoel deformation of two parallel connections, calculating deformation quantity and calculating compensation rate, the deformation of compensation exocoel, the position can exchange.

5, each road adaptive sensing according to claim 1 compensates steady modular system, it is characterized in that: measure exocoel deformation by measuring wavefront slope maximum, wavefront slope average, driving the relevant required driving voltage value of piezoelectricity compensator, and then cooperate corresponding D/A, corresponding high drive module, drive pressure electronic compensating device PZT expands, and the deformation of a direction of external cavity mirror is compensated.

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