WO2020259198A1 - 一种布拉格光栅外腔激光器模块合束装置及合束方法 - Google Patents

一种布拉格光栅外腔激光器模块合束装置及合束方法 Download PDF

Info

Publication number
WO2020259198A1
WO2020259198A1 PCT/CN2020/093137 CN2020093137W WO2020259198A1 WO 2020259198 A1 WO2020259198 A1 WO 2020259198A1 CN 2020093137 W CN2020093137 W CN 2020093137W WO 2020259198 A1 WO2020259198 A1 WO 2020259198A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
beam combining
bragg grating
block
compared
Prior art date
Application number
PCT/CN2020/093137
Other languages
English (en)
French (fr)
Inventor
俞浩
孙舒娟
王俊
潘华东
闵大勇
Original Assignee
苏州长光华芯光电技术有限公司
苏州长光华芯半导体激光创新研究院有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 苏州长光华芯光电技术有限公司, 苏州长光华芯半导体激光创新研究院有限公司 filed Critical 苏州长光华芯光电技术有限公司
Priority to US17/622,964 priority Critical patent/US11631966B2/en
Publication of WO2020259198A1 publication Critical patent/WO2020259198A1/zh

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
    • H01S5/065—Mode locking; Mode suppression; Mode selection ; Self pulsating
    • H01S5/0657—Mode locking, i.e. generation of pulses at a frequency corresponding to a roundtrip in the cavity
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
    • H01S5/4025—Array arrangements, e.g. constituted by discrete laser diodes or laser bar
    • H01S5/4031—Edge-emitting structures
    • H01S5/4062—Edge-emitting structures with an external cavity or using internal filters, e.g. Talbot filters
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/022—Mountings; Housings
    • H01S5/0225—Out-coupling of light
    • H01S5/02251—Out-coupling of light using optical fibres
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/024—Arrangements for thermal management
    • H01S5/02407—Active cooling, e.g. the laser temperature is controlled by a thermo-electric cooler or water cooling
    • H01S5/02415—Active cooling, e.g. the laser temperature is controlled by a thermo-electric cooler or water cooling by using a thermo-electric cooler [TEC], e.g. Peltier element
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/14—External cavity lasers
    • H01S5/141—External cavity lasers using a wavelength selective device, e.g. a grating or etalon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/14—External cavity lasers
    • H01S5/141—External cavity lasers using a wavelength selective device, e.g. a grating or etalon
    • H01S5/142—External cavity lasers using a wavelength selective device, e.g. a grating or etalon which comprises an additional resonator
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
    • H01S5/4012—Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
    • H01S5/4025—Array arrangements, e.g. constituted by discrete laser diodes or laser bar
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/08—Construction or shape of optical resonators or components thereof
    • H01S3/081—Construction or shape of optical resonators or components thereof comprising three or more reflectors
    • H01S3/0813—Configuration of resonator
    • H01S3/0815—Configuration of resonator having 3 reflectors, e.g. V-shaped resonators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/022—Mountings; Housings
    • H01S5/02208—Mountings; Housings characterised by the shape of the housings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/022—Mountings; Housings
    • H01S5/023—Mount members, e.g. sub-mount members
    • H01S5/02325—Mechanically integrated components on mount members or optical micro-benches
    • H01S5/02326—Arrangements for relative positioning of laser diodes and optical components, e.g. grooves in the mount to fix optical fibres or lenses
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
    • H01S5/4006—Injection locking
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
    • H01S5/4025—Array arrangements, e.g. constituted by discrete laser diodes or laser bar
    • H01S5/4031—Edge-emitting structures
    • H01S5/4068—Edge-emitting structures with lateral coupling by axially offset or by merging waveguides, e.g. Y-couplers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
    • H01S5/4025—Array arrangements, e.g. constituted by discrete laser diodes or laser bar
    • H01S5/4087—Array arrangements, e.g. constituted by discrete laser diodes or laser bar emitting more than one wavelength

Definitions

  • the application relates to the field of laser technology, and in particular to a beam combining device and a beam combining method of a Bragg grating external cavity laser module.
  • High-power laser chips are often used as pump sources for solid-state lasers (such as sheet, fiber and slab lasers). Therefore, their efficiency, laser emission space and spectral characteristics determine the performance of solid-state lasers. High-power laser chips are also directly processed with materials (such as surface treatment, welding, additive manufacturing, cutting) and other industrial fields, and they have shown the potential to replace solid-state and fiber lasers. The increase in output power and brightness is the main driving force for the expansion of the application range of direct high-power laser chips. High-power, high-brightness laser output is usually obtained through beam combining technology.
  • Laser beam combining technology is one of the effective methods to obtain high-brightness, high-power semiconductor laser output.
  • Spectral beam combining uses external cavity feedback to lock the wavelengths of different laser chips at a certain wavelength, and uses dispersive elements to combine beams of different wavelengths.
  • the beam quality will deteriorate. If the laser chips are in the same external cavity, the directivity of each laser chip needs to be strictly controlled to ensure that all the laser chips can be oscillated. Otherwise, partial locking of some laser chips will also cause the beam quality and efficiency to decrease.
  • VBG grating Bragg grating
  • the prior art VBG grating external cavity laser module beam combining device includes a plurality of light emitting modules, Fourier transform lenses and gratings arranged side by side and spaced at a required interval.
  • Each light-emitting module includes a laser unit that can emit laser light, and a Bragg grating with different wavelengths emitted by the receiving laser unit.
  • the Bragg grating has a preset locking wavelength, so that the different lasers emitted by each laser unit can be locked at the preset wavelength.
  • Each light-emitting module locks the laser of different wavelengths to form parallel light, and then the parallel light is incident on the Fourier transform lens, which is focused on the grating by the Fourier transform lens, and then formed after diffraction by the grating The combined light shines out.
  • the laser wavelength actually locked by the Bragg grating of each light-emitting module differs from the preset locked laser wavelength, resulting in the combination of the transmission grating output
  • There is a deviation between the laser wavelength contained in the beam and the theoretical laser wavelength contained in the combined beam resulting in a decrease in the quality and power of the combined beam.
  • the prior art VBG grating external cavity laser module beam combining device is difficult to detect or judge In the combined light, which wavelengths of laser light have deviations from the theoretical wavelength laser.
  • the technical problem to be solved by the present application is that it is difficult for the existing VBG grating external cavity laser module beam combining device to detect or determine which wavelengths of laser light in the combined light differ from the theoretical wavelength laser.
  • the purpose of this application is to provide a beam combining device for Bragg grating external cavity laser modules, which includes at least two light-emitting modules spaced apart and arranged side by side, and any one of the light-emitting modules includes a laser unit capable of emitting laser light and is used for receiving the The Bragg grating of the laser light emitted by the laser unit; among them, one of the light-emitting modules is used as a reference light-emitting module; the focusing optical element arranged on the output optical path of all the light-emitting modules; the focusing arranged on the output optical path of the focusing optical element Combining element at position; also includes
  • the light splitting element is arranged on the output light path of the beam combining element
  • the dispersive element is arranged on any output optical path of the light splitting element, and is used to disperse the combined light into dispersed light consistent with the relative positional relationship of the laser of each wavelength between the focusing optical element and the beam combining element ;
  • a conversion optical element arranged on the output optical path of the dispersive element, and used to transmit the dispersed light into parallel light;
  • the image acquisition mechanism is arranged on the output optical path of the conversion optical element, and is used to collect the blocks illuminated by the parallel light on the output optical path of the conversion optical element.
  • the beam combining device of the Bragg grating external cavity laser module there are at least three light-emitting modules, and all the light-emitting modules are arranged side by side at equal intervals.
  • the beam combining element and the dispersive element are both gratings.
  • the beam combining element and the dispersive element are both transmissive gratings or reflective gratings, and the combined light passes through the beam combining element
  • the diffraction angle is the grating blaze angle of the beam combining element
  • the incident angle of the combined light beam incident on the dispersive element is the grating blaze angle of the dispersive element.
  • any of the light-emitting modules further includes an optical fiber arranged on the output optical path of the Bragg grating.
  • the beam combining device of a Bragg grating external cavity laser module further includes a temperature control device, and the temperature control device includes
  • the temperature control element is arranged on the Bragg grating
  • a temperature detection element for detecting the temperature of the Bragg grating
  • a controller is electrically connected to both the temperature adjustment element and the temperature detection element, and the controller controls the temperature increase or decrease of the temperature adjustment element according to the detection signal of the temperature detection element.
  • the purpose of this application is also to provide the beam combining method of the above-mentioned Bragg grating external cavity laser module beam combining device, which includes the following steps:
  • the image includes a reference block and a number of blocks to be compared, wherein the reference block corresponds to the output wavelength of the reference light-emitting module laser, the block to be compared and other light-emitting modules One-to-one correspondence of the output wavelength of the laser;
  • the picture block to be compared exceeds the range of the respective preset picture block, adjust the lock wavelength of the Bragg grating in the light emitting module corresponding to the picture block to be compared so that the picture block to be compared falls into the respective corresponding Within the preset tiles.
  • the beam combining method of the beam combining device of the Bragg grating external cavity laser module in the step of determining whether the block to be compared falls within the range of the respective preset block,
  • the difference between the picture block to be compared and the respective preset picture block is not more than 2 pixels, it indicates that the picture block to be compared falls within the range of the respective preset picture block.
  • the beam combining method of the Bragg grating external cavity laser module beam combining device Preferably, the beam combining method of the Bragg grating external cavity laser module beam combining device,
  • the locking wavelength of the Bragg grating is adjusted.
  • the reference image is equal to the spacing between any adjacent preset tiles.
  • a beam combining device for VBG grating external cavity laser modules provided by this application includes a plurality of light emitting modules arranged side by side.
  • the light emitting modules adopt Bragg gratings for wavelength locking; the output light enters the beam combining element after passing through the focusing optical element.
  • the beam is combined under the action of the beam combining element, and part of the combined light is reflected to the dispersive element after the action of the beam splitting element to disperse into sub-beams with different exit angles, and form parallel light under the action of the transforming optical element, and on the image acquisition mechanism
  • the light-emitting module can not perform wavelength locking judgment and detection, which causes the problem of low beam quality of the beam combining device.
  • the beam combining device has a simple structure, rapid judgment and detection, and convenient adjustment.
  • each light-emitting module includes multiple laser chips, and the multiple laser chips are arranged in steps to achieve spatial beam combining, and multiple laser chips in each module emit The laser is locked at the same wavelength, there is no crosstalk, and it also solves the problem of limited beam combining unit in spatial beam combining, and can integrate multiple lasers in a smaller space, making the entire laser chip module smaller in size; also A larger number of single-tube beams can be coupled into the optical fiber, thereby having a larger output power, and the combined output beam has high brightness.
  • a VBG grating external cavity laser module beam combining device provided by this application includes a temperature control device connected to the Bragg grating.
  • the temperature control device includes a heating element, a temperature detection element and a controller, and the luminescence collected by the image acquisition mechanism When the block corresponding to the module has a deviation, the controller controls the heating element to turn on or off according to the detection signal of the temperature detection element.
  • the temperature control device adjusts the temperature of the Bragg grating of the deviation light-emitting module to make the output of the light-emitting module The light reaches the preset locked wavelength.
  • a beam combining method for a beam combining device of a VBG grating external cavity laser module is to acquire an image through an image acquisition device, and use the block formed by the reference light emitting module on the image acquisition mechanism as a reference block, and other blocks
  • each block corresponds to a laser with the output wavelength of the light-emitting module
  • use the reference block as a reference to obtain the respective preset block range corresponding to each block to be compared
  • compare the block to be compared with each The preset block range comparison determine whether the block to be compared falls within the corresponding preset block range; if the block to be compared exceeds the range of the respective preset block, adjust the corresponding block to be compared
  • the wavelength of the Bragg in the light-emitting module is locked, so that the picture block to be compared falls within the respective preset picture block range.
  • the preset block range of the block of the module Calculate the preset block range of the block of the module to be compared on the image capture mechanism based on the block of the reference module on the image capture mechanism, and then compare the block of the block to be compared from the image capture with the preset block range , To determine whether there is a deviation, that is, whether it falls within the preset block range, use the relationship between the deviation and the diffraction angle after the dispersive element, and then convert it into wavelength according to the grating equation, and use the relationship between wavelength and Bragg grating temperature to convert it into For the temperature difference, the locked wavelength can be adjusted by adjusting the temperature of the Bragg grating; the beam combining method is simple, and the adjustment is quick and effective.
  • FIG. 1 is a structural diagram of the light-emitting module of this application directly outputting laser light and the beam combining element is a transmissive grating;
  • FIG. 2 is a structural diagram of the light-emitting module of this application directly outputting laser light and the beam combining element is a reflective grating;
  • FIG. 3 is a structural diagram of the light-emitting module of this application in which the laser is coupled into the optical fiber to realize the pigtail output and the beam combining element is a transmissive grating;
  • FIG. 4 is a structural diagram of the light-emitting module of this application in which the laser is coupled into the optical fiber to realize the pigtail output and the beam combining element is a reflective grating;
  • Figure 5 is a structural diagram of the light-emitting module of this application.
  • Figure 6 is a schematic diagram of the light path of the light-emitting module of this application.
  • FIG. 7 is a structural diagram of the temperature control element of this application.
  • FIG. 8 is a schematic structural diagram of the theoretical position range of the blocks on the image acquisition mechanism of the light-emitting module of this application;
  • FIG. 9 is a schematic structural diagram of the light-emitting module of the application when the block to be compared on the image acquisition mechanism is shifted to the left;
  • FIG. 10 is a schematic diagram of the structure of the light-emitting module of the application when the block to be compared on the image acquisition mechanism is shifted to the right.
  • 1-light-emitting module 100-reference light-emitting module; 101-10N-light-emitting module; 101'-10N'-light-emitting module; 11-laser unit; 111-11n-laser single tube chip; 12-fast-axis collimating lens; 121 -12n-fast-axis collimating lens; 13-slow-axis collimating lens; 131-13n-slow-axis collimating lens; 14-reflection mirror; 141-14n-reflection mirror; 15-light exit hole; 16-Bragg grating; 17 -Temperature control device; 18-heat conducting glass; 19-wire;
  • connection should be interpreted broadly unless otherwise clearly specified and limited.
  • it can be a fixed connection or a detachable connection. Connected or integrally connected; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication between two components.
  • connection should be interpreted broadly unless otherwise clearly specified and limited.
  • it can be a fixed connection or a detachable connection. Connected or integrally connected; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication between two components.
  • the beam combining device of the VBG grating external cavity laser module of this embodiment includes multiple light emitting modules 1, a focusing optical element 2, a beam combining element 3, a beam splitting element 4, and a dispersive element 5.
  • the beam splitting element 4 divides the combined light into reflected light and transmitted light, part of the combined light passes through the beam splitting element 4 for output, and the other part of the combined light reflects To the dispersive element 5 on the optical path of the reflected light, the dispersive element 5 disperses the combined light into dispersed light consistent with the relative positional relationship of the laser of each wavelength between the focusing optical element 2 and the combining element 3, that is, the light-emitting module 1
  • the exit angle ⁇ n of the output light after passing through the dispersive element 5 forms a one-to-one correspondence with the incident angle ⁇ n on the beam combining element 3.
  • the first light-emitting module is incident on the beam combining element 3 at an incident angle ⁇ 1 , in the angle beta] 1 from the dispersive element exit, the N-th light emitting modules incident angle [alpha] N incident beam combining element 3 to an angle beta] N from the dispersive element emitted; each of the light emitting module output light is a laminated beam elements 3
  • the light beams after being dispersed by the dispersive element 5 form parallel spaced light under the transforming action of the transforming optical element 6, and the output light wavelength of each light-emitting module 1 is formed on the image acquisition mechanism 7 on the exit surface of the transforming optical element 6. Corresponding tiles.
  • the light-emitting modules in this application are two, three, four, five, etc., and the specific number is not limited. One of them is used as a reference module, and the other light-emitting modules are set symmetrically on the upper and lower sides of the reference module with reference to the reference module. It can also be that all other light-emitting modules are arranged on the upper side or all on the lower side of the reference module.
  • the center wavelength of each light-emitting module 1 after being wavelength-locked by the Bragg grating 16 is different; for example, the center wavelength of the output light of the reference light-emitting module 100 after being wavelength-locked by the Bragg grating 16 ⁇ 0 , the center wavelength of the output light of the light-emitting module 101 is ⁇ 1 , the center wavelength of the output light of the light-emitting module 101 ′ is ⁇ -1, the center wavelength of the output light of the light - emitting module 10N is ⁇ N , and the output light center of the light-emitting module 10N′
  • the wavelength is ⁇ -N, and the center wavelength of other light-emitting modules can be deduced by analogy.
  • the Bragg grating 16 of the present application is a vertical reflective Bragg grating, the reflectivity is in the range of 10% to 30%, the reflection bandwidth is less than 1 nm, the temperature drift coefficient is about 0.01 nm/°C, and the temperature and wavelength are linearly related to meet the following relationships formula:
  • ⁇ (T) is the central wavelength at the temperature T
  • ⁇ 0 is the central wavelength at the temperature T 0
  • 0.01 is the coefficient of wavelength drift with temperature, in nm/°C
  • the beam splitting element 4 of the present application may be an existing non-polarization flat beam splitter, or a cube type, which is not specifically limited.
  • the main purpose is to divide the output light emitted by the light-emitting module into two beams of reflected light and transmitted light.
  • the specific structure and working principle are not described and limited here, and can be selected according to actual needs.
  • the light-emitting module 1 of the present application is a square box-shaped laser module with a laser unit 11 for emitting laser light.
  • the laser unit 11 is a single-tube laser chip, arranged in steps in the fast axis direction.
  • the upper side of the light emitting module 1 (the upper left corner as shown in Fig. 1) is provided with a light exit hole 15 for emitting laser light.
  • the reflective surfaces of the multiple reflectors 14 are arranged toward the light exit hole 15, and the reflector A Bragg grating 16 is arranged between 14 and the light exit hole 15, and the Bragg grating 16 is connected to a temperature control device 17 through a heating element.
  • the multiple laser units 11 in each light-emitting module 1 are arranged side by side in the slow axis direction, that is, in the horizontal direction, and are arranged in steps along the fast axis direction, that is, in the vertical direction; specifically, as shown in FIG.
  • each light-emitting module 1 includes multiple The single-tube laser chips 111-11n, and multiple single-tube laser chips 111-11n are arranged on the multi-level steps in a one-to-one correspondence, arranged in a step array and the height difference between two adjacent laser single-tube chips is equal;
  • the exit surface of the tube chip is provided with a collimating system and a mirror in sequence.
  • the collimating system includes a fast axis collimating lens and a fast axis collimating lens arranged in sequence along the exit surface of a single laser tube chip for compressing the divergence angle in the fast axis direction of the laser.
  • a slow-axis collimating lens used to compress the divergence angle of the slow-axis direction of the laser.
  • the reflecting mirror 14 is arranged on the exit surface of the slow-axis collimating lens, and a plurality of reflecting mirrors 14 are correspondingly arranged on another row of multi-step steps.
  • the steps are arranged, and the height difference between two adjacent mirrors 14 is also equal; the light emitted by multiple laser single-tube chips is completely collimated by the collimating system, and moves in the fast axis direction under the action of the corresponding mirrors.
  • a larger number of single-tube laser chips can be arranged in a smaller space.
  • the reflector 14 is a 45-degree reflector and is arranged perpendicular to the horizontal plane, and is at 45° with the optical axis of the collimating system composed of the fast-axis collimator lens and the slow-axis collimator lens.
  • the multiple reflectors 14 are arranged to realize multiple semiconductor lasers.
  • the laser light emitted by the tube chip is combined spatially, and forms a spatially combined beam after the action of the reflector 14.
  • the spatially combined beam is incident on the Bragg grating 16, a part of the spatially combined light passes through the Bragg grating 16 as the output light, and the other part serves as the output light.
  • the feedback light returns to the inside of the laser single-tube chip to lock the wavelength of the laser emitted by the semiconductor laser single-tube chip.
  • the Bragg grating 16 and the laser single-tube chip form an external cavity.
  • the feedback light forms a mode competition inside the chip to achieve wavelength Select so that the light-emitting module 1 outputs at a locked wavelength.
  • the front cavity surface of the laser single tube chip of the present application is plated with an anti-reflection film chip, but it is not specifically limited.
  • the fast-axis collimating lens 12 and the slow-axis collimating lens 13 of the present application are collimating lenses currently on the market, and their specific structures and working principles are not described and limited herein, and can be selected according to actual needs.
  • the fast-axis collimator lens 12 and the slow-axis collimator lens 13 of the present application are both coated with anti-reflection coatings. Due to the reduction of beam reflection, the transmittance after coating should be within the range of the wavelength of the laser chip's beam. More than 99%, there is no limitation.
  • the principle of the light path of the light-emitting module 1 of the present application is shown in FIG. 6, the laser light emitted by the laser single tube chip 111 is collimated by the fast axis collimating lens 121 in the fast axis direction, and the light collimated in the fast axis direction reaches the slow axis collimation.
  • the light collimated in the fast axis direction is collimated in the slow axis direction by the slow axis collimating lens 131 to become a fully collimated light, and the completely collimated light is reflected by the exit surface of the slow axis collimating lens 131 141 is reflected and emitted from the module; the light emitted from the laser single-tube chip 112 with a step height difference with the laser single-tube chip 111 is collimated by the fast-axis collimating lens 122 and the slow-axis collimating lens 132 and then reaches the mirror 142, and is reflected
  • the mirror 142 and the reflector 141 also have a step height difference.
  • the light emitted by the laser single tube chip 112 is emitted by the reflector 142 and then passes over the reflector 141 to achieve beam combination with the light emitted by the laser single tube chip 111 in the fast axis direction.
  • the laser light emitted by a single laser tube chip arranged in multiple steps is spatially combined to form the output light of the light emitting module 1.
  • Each light-emitting module 1 includes multiple laser single-tube chips.
  • the multiple laser single-tube chips are arranged in a step height difference. More semiconductor laser single-tubes can be integrated in a smaller space. After the light beams are spatially combined, they can be directly output or coupled into the optical fiber 8 through an aspherical focusing lens (not shown) to form a pigtail light emitting module, thereby having a larger output power.
  • the beam combining element 3 of the present application is a grating, which is set toward the convex surface of the Fourier transform lens.
  • the polarization of the beam combining element 3 should be consistent with the polarization of the light beam emitted by the light emitting module; the diffraction efficiency of the grating should be above 90% in the corresponding polarization direction ;
  • the center wavelength of the grating is in the range of ⁇ 0 ⁇ n ; the grating is placed at a blaze angle relative to the optical axis; it can be a transmissive grating or a reflective grating.
  • the dispersive element 5 of the present application is a grating, and the center wavelength of the grating is in the range of ⁇ 0 to ⁇ n ; it can be a transmissive grating or a reflective grating. Its structure and working principle are not described and limited here, and can be based on actual conditions. Need to choose.
  • the combining element 3 and the dispersing element 4 of the present application are placed at respective blaze angles relative to the optical axis; for example, the output light of each light-emitting module 1 passes through the combining element 3 and the combined light combined with the combining element 3 has a diffraction angle ⁇ Littrow exits, a part of the outgoing beam after the beam splitting element 4 is incident on the dispersing element 5 at a diffraction angle ⁇ Littrow ; the two diffraction angles can be equal or unequal, depending on the combining element 3 and the dispersing element 5 Whether it is the same grating, if it is the same grating, the diffraction angles of the two are equal; if they are not the same grating, they are not equal; correspondingly, when the beam combining element 3 and the dispersive element 5 are the same grating, the light-emitting module 1
  • the incident angle ⁇ n of the output light incident on the beam combining element 3 is equal to the exit angle
  • the beam combining element 3 and the dispersive element 5 of the present application can be both transmissive gratings and reflective gratings at the same time.
  • One of the transmissive gratings and the other reflective grating can also be used.
  • the specific selection is not limited, as long as it can be realized After combining the beams, disperse again; as shown in Figures 1 to 4, the output light of the light-emitting module located above the reference module 100 passes through the combining element 3, the light splitting element 4 and the dispersing element 5, and the exit direction is to the right, and is located at After the output light of the light emitting module under the reference module 100 passes through the combining element 3, the light splitting element 4, and the dispersing element 5, the exit direction is to the left.
  • the focusing optical element 2 of the present application is a Fourier transform lens.
  • the Fourier transform lens is a cylindrical lens with a flat surface and a convex surface. The flat side faces the light-emitting module 1 and the convex side faces away from the light-emitting module 1 and faces the combining element. 3 settings.
  • the specific structure and working principle are not described and limited here, and Fourier transform lenses with different focal lengths can be selected according to actual needs. For example, it is known from the above formula that in order to obtain more beam combining units within the same spectral width, a long focal length Fourier transform lens can be selected, which can be selected according to actual needs.
  • the focusing optical element 2 of the present application may also be other common focusing optical elements, as long as it can achieve focusing and incident laser light of different wavelengths emitted by different light-emitting modules to the beam combining element.
  • the conversion optical element 6 of the present application is an existing ordinary conversion cylindrical lens, as long as it can transform the sub-beams with different exit angles dispersed by the dispersive element 5 into parallel sub-beams.
  • the specific structure and principle will not be described. limited.
  • the temperature control device 17 of the present application includes a temperature adjustment element, which is connected to the Bragg grating 16; a temperature detection element (not shown), used to detect the temperature of the Bragg grating 16; a controller (not shown), and the temperature adjustment element and The temperature detection elements are electrically connected, and the controller controls the heating or cooling of the heating element according to the detection signal of the temperature detection element; the temperature adjustment element includes a heating element or a refrigeration element; when the temperature needs to be raised, the heating element is turned on; when the temperature needs to be cooled, it is turned on Refrigeration components. As shown in FIG.
  • the temperature control device 16 of the present application is a common TEC temperature control device on the existing market, and its specific structure and working principle are not described and limited here, and it is in contact with the Bragg grating 16 through the thermally conductive glass 18 , Is electrically connected to the controller through a wire 19, the controller is connected to the image acquisition mechanism 7, and a closed loop connection is formed between the image acquisition mechanism 7 and the Bragg grating 16; the output light of the light-emitting module 1 is collected by the image acquisition mechanism 7 in the image acquisition mechanism The above imaging block is compared with the preset block range to determine whether there is a deviation.
  • the controller converts the deviation into the wavelength deviation of the laser emitted by the light-emitting module 1, and then converts it into the Bragg grating corresponding to the light-emitting module 1.
  • the temperature deviation of the Bragg grating 16 and the wavelength the temperature difference between the Bragg grating 16 of the light-emitting module 1 and the preset Bragg grating 16 is obtained, and the temperature of the Bragg grating 16 is adjusted by the temperature control device 17
  • the temperature causes the wavelength of the laser light emitted by the light-emitting module 1 to reach the preset wavelength range, and wavelength locking is achieved.
  • the image acquisition mechanism 7 of the present application is a CCD, such as a linear CCD or an area CCD, which is not particularly limited. Of course, it can also be other image acquisition devices in the prior art. The specific structure and working principle of the image acquisition device are not described here. Definition and description.
  • the dispersion characteristics of the grating, the n-th emission center wavelength modules need to be locked in the [lambda] n, the n-th light emitting modules lock the wavelength [lambda] n and the reference reference module
  • the lock wavelength ⁇ 0 corresponding to 100 satisfies the following geometric relationship:
  • ⁇ 0 is the center wavelength of the reference light-emitting module
  • ⁇ n is the center wavelength of the n-th light-emitting module
  • d is the grating period of the grating
  • p is the interval of the light-emitting module
  • f TL is the focal length of the focusing optical element
  • ⁇ Ltirrow is the grating Flare angle
  • the wavelength and incident angle satisfy the following geometric relationship
  • ⁇ n is the center wavelength of the output light of the nth light-emitting module
  • ⁇ n is the incident angle of the output light of the nth light-emitting module to the beam combining element 3
  • ⁇ Littrow is the grating blaze angle of the beam combining element 3.
  • the center wavelength of the output light of the nth light-emitting module needs to be locked at ⁇ n , and the locked wavelength is calculated as
  • the combined beam wavelength interval is proportional to the grating period and the light-emitting module interval, and inversely proportional to the focal length of the focusing optical element; therefore, the combined beam wavelength interval can be reduced by selecting a long focal length focusing optical element method, so that the More beam combining units can be accommodated in the same wide spectral range, thereby providing system power and increasing the output beam brightness of the system.
  • the beam combining element 3 of this system is a transmissive grating.
  • the transmissive grating is placed at a blaze angle ⁇ Littrow relative to the optical axis.
  • the laser light emitted by the n laser chips 11 of the n light-emitting modules passes through the collimation system. After being completely collimated, the beams are combined in the fast axis direction by the reflection mirror to reach the Bragg grating 16, and the wavelength is locked by the Bragg grating 16 and output from the light exit 15 to the Fourier transform lens.
  • different light-emitting modules 1 The position information of the emitted lasers of different wavelengths is converted into angle information and then focused and incident on the surface of the transmissive grating at different incident angles ⁇ n . Under the action of the transmissive grating, different sub-beams have the same diffraction angle ⁇ Littrow (combined beam). The grating blaze angle of element 3) is output to form combined light. The combined light irradiates the surface of the beam splitter 4, and is divided into reflected light and transmitted light under the action of the beam splitter 4.
  • the transmitted light passes through the beam splitter 4 and is output, and the reflected light passes through after the reflective spectral element 4 at an incident angle ⁇ Littrow (dispersive element 5 of the grating blaze angle) is incident to the grating surface; under the action of the dispersion grating redispersed into sub-beams at different angles, ⁇ n of each sub-beam output, converting incident
  • the optical element 6 forms parallel light output of each sub-beam under the action of the transforming optical element 6 and vertically imaged it on the CCD, forming evenly spaced blocks on the CCD.
  • the transmissive grating of the present application is a transmissive grating on the existing market, and its specific structure and working principle are not limited and described herein, and can be selected according to actual needs.
  • the beam combining element 3 of this system is a reflective grating.
  • the reflective grating is placed at a blaze angle ⁇ Littrow relative to the optical axis.
  • the laser light emitted by the n laser chips 11 of the n light-emitting modules 1 is collimated After the system is fully collimated, the beams are combined in the fast axis direction by the reflection mirror, and then reach the Bragg grating 16. After the wavelength is locked by the Bragg grating 16, the output from the light hole 15 to the Fourier transform lens will be different after Fourier transform.
  • each beam has the same reflection angle ⁇ Littrow ( The grating blaze angle of the beam combining element is output to form combined light.
  • the combined light is reflected to the surface of the beam splitting element 4, and is divided into reflected light and transmitted light under the action of the beam splitting element 4.
  • the transmitted light is output through the beam splitting element, and the reflected light passes through
  • the beam splitting element 4 is also incident on the grating surface with ⁇ Littrow (the grating blaze angle of the dispersive element) after reflection, and is re-dispersed into sub-beams of different angles under the action of the dispersion of the grating, and each sub-beam is output as ⁇ n and incident to the transformation optical element 6.
  • the sub-beams are formed into parallel light output and vertically imaged on the CCD, forming equally spaced blocks on the CCD.
  • the reflective grating of the present application is a reflective grating on the existing market, and its specific structure and working principle are not limited and described herein, and can be selected according to actual needs.
  • the above ⁇ Littrow and ⁇ Littrow are equal when the beam combining element 3 and the dispersive element 5 are the same grating, and are not equal when they are not the same grating; in the same way, the above ⁇ n and ⁇ n beam combining element 3 and the dispersive element 5 are It is equal when the same grating is used, and different when it is not the same grating.
  • the beam combining method of this implementation is based on the beam combining device of the Bragg grating external cavity laser module in Embodiment 1, as shown in FIG. 1 to FIG. 10, and includes the following steps:
  • the image includes a reference block and a number of blocks to be compared, where the reference block corresponds to the laser light of the output wavelength ( ⁇ 0 ) of the reference light-emitting module 100 (the light-emitting module labeled ⁇ 0 in FIG. 1 ), to be compared
  • the blocks correspond to the lasers of the output wavelengths of other light-emitting modules (the light-emitting modules marked ⁇ 1 - ⁇ N and ⁇ -1 - ⁇ -N in Figure 1);
  • the block to be compared exceeds the range of the respective preset block, adjust the lock wavelength of the Bragg grating in the light-emitting module corresponding to the block to be compared, so that the block to be compared falls into the range of the respective preset block Inside.
  • the difference between the block to be compared and the respective preset block is not more than 2 pixels, it indicates that the block to be compared falls within the range of the respective preset block.
  • the locked wavelength of the Bragg grating can be adjusted.
  • the distance between the reference tile and its neighboring preset tile is different from any neighboring preset tile. The spacing between them is equal.
  • the above-mentioned preset block range can be used for each block to be compared and the reference block To describe the location interval.
  • the combined light beam combined by the beam combining element 3 and the beam combining element are emitted at a diffraction angle ⁇ Littrow , and a part of the outgoing beam after the action of the beam splitting element 4 is incident on the dispersive element 5 at ⁇ Littrow .
  • the light-emitting module to be compared (the light-emitting module whose output wavelength is ⁇ 1 - ⁇ N and ⁇ -1 - ⁇ -N is marked in the figure) is up and down relative to the reference light-emitting module 100 (the light-emitting module whose output wavelength is ⁇ 0 is marked in the figure) Symmetrical arrangement, the block to be compared formed on the image acquisition mechanism 7 by the output light of the module to be compared is symmetrical with respect to the reference block on the image acquisition mechanism 7 of the output light of the reference reference module 100; by the above formula (7 ) It is known that the locked wavelength of the output light of the light-emitting module 1 decreases by ⁇ from top to bottom, and the corresponding wavelength of the corresponding block on the image acquisition mechanism 7 also gradually decreases by ⁇ from left to right. The corresponding wavelengths of the tiles are equally spaced, so the intervals between adjacent tiles are also equal;
  • the theoretical interval value p 0 between adjacent blocks can be calculated, and thus, the preset block range of the block to be compared on the image acquisition mechanism 7 of each module to be illuminated can be obtained;
  • the light-emitting module with the locked wavelength ⁇ 0 as a reference, and its block on the image acquisition mechanism 7 is used as a reference block.
  • the theoretical interval between the block to be compared and the reference block is pre-existed in the controller Inside.
  • the imaged blocks of the output light of the light-emitting module on the image acquisition mechanism are all in the theoretical position, that is, the imaged blocks of the output light of each light-emitting module on the image acquisition mechanism are all within the preset block range .
  • the image acquisition mechanism 7 collects the actual image information of the blocks of each light-emitting module 1.
  • the image acquisition mechanism processes the actual image information, converts the image information into position information, and obtains the processed image.
  • the image acquisition mechanism 7 collects each light-emitting module.
  • the actual position information of the blocks of module 1 is fed back to the controller, and the controller analyzes the actual intervals between the blocks to be compared and the reference blocks of each light-emitting module to be compared; the actual blocks of the reference blocks are collected
  • the controller performs calculation and analysis to obtain the preset block range of each module to be compared.
  • the controller compares the actual block of each light-emitting module to be compared with the corresponding preset block range to determine the actual picture Whether the block falls within the preset block range, that is, whether there is a deviation from the preset block range, the controller converts the block deviation into the wavelength deviation of the output light of the light-emitting module corresponding to the block, and then according to the Bragg grating 16
  • the temperature drift characteristic converts the wavelength deviation into the temperature deviation, and then obtains the specific values of whether the temperature should rise or fall, and the rise and fall, and then the controller controls the temperature control device 17 to adjust the temperature of the Bragg grating 16 to realize the adjustment and realize multiple light-emitting modules ⁇ .
  • the block to be compared of the nth light-emitting module read by the controller has a deviation from the preset block range, and suppose this deviation is L (left deviation is a negative value, as shown in Figure 9; right deviation is a positive value, As shown in Figure 10), it can be seen from the characteristics of the grating that the diffraction angle of the output light of the light-emitting module 1 to be compared at the dispersive element 5 is set to ⁇ n ', according to the geometric relationship
  • the controller compares the actual locked wavelength with the theoretically calculated locking wavelength of the light-emitting module (calculated by the above formula (8));
  • the geometric relationship between the temperature and the wavelength of the Bragg grating 16 in the above embodiment 1 is converted from the wavelength deviation to the temperature deviation.
  • the light-emitting module is obtained
  • the actual temperature of the Bragg grating 16 of 1 is then compared with the preset temperature to obtain specific values of whether the temperature should increase or decrease, and the increase and decrease;
  • the temperature of the Bragg grating 16 is adjusted by the temperature control device 17 to raise or lower the temperature to adjust the lock wavelength of the corresponding light-emitting module 1.
  • the temperature detection element detects the actual temperature of the Bragg grating 16, and the controller controls the temperature according to the calculated and analyzed temperature difference.
  • the heating or cooling element is turned on, and the heat is transferred to the Bragg grating 16 through the thermally conductive glass; when the temperature detecting element detects that the temperature of the Bragg grating 16 reaches the preset value, the controller controls the heating or cooling element to turn off; the thermally conductive element is in contact with the Bragg grating Heat exchange occurs.

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optics & Photonics (AREA)
  • Semiconductor Lasers (AREA)
  • Optical Couplings Of Light Guides (AREA)

Abstract

一种布拉格光栅外腔激光器模块合束装置及合束方法。其中，合束装置包括多个并排设置的发光模块（1，100，101-10N，101'-10N'），采用布拉格光栅（16）进行波长锁定；输出光经聚焦光学元件（2）后入射至合束元件（3）进行合束，合束光经分光元件（4）作用后一部分反射，一部分透射，其中的一部分以色散元件（5）的衍射角入射到色散元件（5）上，并在变换光学元件（6）作用下形成平行光；最后在图像采集机构（7）上形成与发光模块（1，100，101-10N，101'-10N'）对应波长的光束的图块；通过图像采集机构（7）上的发光模块（1，100，101-10N，101'-10N'）形成的图块与预设图块之间是否存在偏差来判断对应的发光模块（1，100，101-10N，101'-10N'）的波长是否锁定，有效解决现有的多发光模块的合束装置无法进行锁定波长的判断和检测造成的合束装置光束质量较低的问题，合束装置结构简单，判断检测快速，调整方便。

Description

一种布拉格光栅外腔激光器模块合束装置及合束方法 技术领域
本申请涉及激光器技术领域，具体涉及一种布拉格光栅外腔激光器模块合束装置及合束方法。
背景技术
大功率激光器芯片常被用作固体激光器(如薄片，光纤和板条激光器)的泵浦源，因此其效率、激光发射的空间和光谱特性决定了固体激光器的性能。大功率激光器芯片也被直接用材料加工(如表面处理，焊接，增材制造，切割)等工业领域，并且显示了替代固体和光纤激光器的潜力。输出功率和亮度的增加是直接大功率激光器芯片应用范围扩大的主要驱动力。通常通过合束技术获得高功率、高亮度的激光输出。
激光合束技术是获得高亮度、高功率半导体激光输出的有效方法之一。光谱合束是通过外腔反馈，将不同激光器芯片波长锁定在一定波长，利用色散元件将不同波长光束合成一束，但是外腔光谱合束由于存在串扰问题，将导致光束质量的恶化，另外多个激光器芯片在同一外腔中，需严格控制各激光器芯片的指向性一致以保证能够全部起振，否则部分激光器芯片部分锁定也将导致光束质量和效率下降。
近年来，采用布拉格光栅(VBG光栅)的反馈方式来实现高功率激光器芯片的波长锁定和光谱线宽的窄化，以增强对环境的适应性，扩大其应用范围。
现有技术中VBG光栅外腔激光器模块合束装置包括若干个并排且间隔所需间距布置的发光模块、傅里叶变换透镜及光栅。其中每个发光模块包括可发射激光的激光单元，及接收激光单元发射出不同波长的布拉格光栅,布拉格光栅具有预设锁定波长，从而实现将每个激光单元发射出的不同激光锁定在预设波长的激光上并发射出去；每个发光模块锁定不同波长的激光形成平行光，之后平行光均入射至傅里叶变换透镜上，经傅里叶变换透镜聚焦在光栅上，再经光栅衍射后形成合束光照射出去。
但是，上述的VBG光栅外腔激光器模块合束装置，在实际使用过程中，由于每个发光模块的布拉格光栅实际锁定的激光波长与预设锁定的激光波长存在偏差，导致透射式光栅输出的合束光中包含的激光波长与理论的合束光包含的激光波长存在偏差，造成合束光的质量和功率的下降，可现有技术中的VBG光栅外腔激光器模块合束装置难以检测或判断出，合束光中的哪些波长的激光与理论的波长激光存在偏差。
发明内容
因此，本申请所要解决的技术问题在于现有的VBG光栅外腔激光器模块合束装置难以检测或判断出，合束光中的哪些波长的激光与理论的波长激光存在偏差。
本申请的目的在于提供一种布拉格光栅外腔激光器模块合束装置，包括至少两个间隔且并排布置的发光模块，任一所述发光模块包括可发射激光的激光单元，及用于接收所述激光单元发射出的激光的布拉格光栅；其中，一个所述发光模块作为基准发光模块；设在所有所述发光模块的输出光路上的聚焦光学元件；设在所述聚焦光学元件的输出光路的聚焦位置处的合束元件；还包括
分光元件，设在所述合束元件的输出光路上；
色散元件，设在所述分光元件的任一输出光路上，用于将合束光分散为与所述聚焦光学元件和所述合束元件之间的各个波长的激光相对位置关系一致的分散光；
变换光学元件，设在所述色散元件的输出光路上，用于将所述分散光透射为平行光；
图像采集机构，设在所述变换光学元件的输出光路上，用于采集所述变换光学元件的输出光路上的平行光照射的图块。
优选地，所述的一种布拉格光栅外腔激光器模块合束装置，所述发光模块为至少三个，所有所述发光模块等间距并列排布。
优选地，所述的一种布拉格光栅外腔激光器模块合束装置，所述合束元件和所述色散元件均为光栅。
优选地，所述的一种布拉格光栅外腔激光器模块合束装置，所述合束元件和所述色散元件均为透射式光栅或反射式光栅，所述合束光经所述合束元件的衍射角为所述合束元件的光栅闪耀角，所述合束光入射至所述色散元件的入射角为所述色散元件的光栅闪耀角。
优选地，所述的一种布拉格光栅外腔激光器模块合束装置，任一所述发光模块还包括设在所述布拉格光栅的输出光路上的光纤。
优选地，所述的一种布拉格光栅外腔激光器模块合束装置，还包括温控装置，所述温控装置包括
调温元件，设在所述布拉格光栅上；
温度检测元件，用于检测所述布拉格光栅的温度；
控制器，与所述调温元件和所述温度检测元件均电连接，所述控制器根据所述温度检测元件的检测信号，控制所述调温元件的升温或降温。
本申请的目的还在于提供上述的布拉格光栅外腔激光器模块合束装置的合束方法，包括以下步骤：
获取图像，所述图像包括参考图块及若干个待比较图块，其中所述参考图块对应于所述基准发光模块的输出波长的激光，所述待比较图块与其他的所述发光模块的输出波长的激光一一对应；
基于所述参考图块，获取各个待比较图块各自对应的预设图块范围；
将任一所述待比较图块与各自对应的预设图块范围比较；
判断所述待比较图块是否落入各自对应的预设图块范围内；
若待比较图块超出各自对应的预设图块范围外，调整该所述待比较图块对应的所述发光模块中布拉格光栅的锁定波长，以使该所述待比较图块落入各自对应的预设图块范围内。
优选地，所述的布拉格光栅外腔激光器模块合束装置的合束方法，在判断所述待比较图块是否落入各自对应的预设图块范围内的步骤中，
待比较图块与各自对应的预设图块的偏差不大于2个像素点，则表明所述待比较图块落入各自对应的预设图块范围内。
优选地，所述的布拉格光栅外腔激光器模块合束装置的合束方法，
在所述若待比较图块超出各自对应的预设图块范围外，调整该所述待比较图块对应的所述发光模块中布拉格光栅的锁定波长的步骤中，
通过调整该所述待比较图块对应的所述发光模块中布拉格光栅的温度，以调整该所述布拉格光栅的锁定波长。
优选地，所述的布拉格光栅外腔激光器模块合束装置的合束方法，在基于所述参考图块，获取各个待比较图块各自对应的预设图块范围的步骤中，所述参考图块与其相邻的预设图块之间的间距，与任意相邻的预设图块之间的间距相等。
本申请技术方案，具有如下优点：
1.本申请提供的一种VBG光栅外腔激光器模块合束装置，包括多个并排设置的发光模块，发光模块采用布拉格光栅进行波长锁定；输出光经聚焦光学元件后入射至合束元件，在合束元件的作用下进行合束，合束光经分光元件作用后一部分反射至色散元件上分散成不同出射角度的子束，并在变换光学元件作用下形成平行光，并在图像采集机构上形成与发光模块对应波长的光束的图块；通过图像采集机构上的发光模块形成的图块与预设图块之间是否存在偏差来判断该对应的发光模块的波长是否锁定，有效解决现有 的发光模块无法进行波长锁定的判断和检测造成的合束装置光束质量较低的问题，合束装置结构简单，判断检测快速，调整方便。
2.本申请提供的一种VBG光栅外腔激光器模块合束装置，每个发光模块包括多个激光器芯片，多个激光器芯片呈台阶排布实现空间合束，每个模块的多个激光器芯片发射的激光被锁定在同一波长，不存在串扰，同时也解决了空间合束中合束单元受限的问题，可以在较小的空间内集成多路激光，使得整个激光器芯片模块尺寸较小；也可以将更多数量的单管的光束耦合进光纤，从而具有更大的输出功率，合束输出光束亮度高。
3.本申请提供的一种VBG光栅外腔激光器模块合束装置，包括温控装置，与布拉格光栅连接，温控装置包括加热元件、温度检测元件和控制器，在图像采集机构采集到的发光模块对应的图块产生偏差时，控制器根据温度检测元件的检测信号，控制加热元件的开启或关闭，通过温控装置对发生偏差的发光模块的布拉格光栅进行温度调节，使得该发光模块的输出光达到预设锁定波长。
4.本申请提供的一种VBG光栅外腔激光器模块合束装置的合束方法，通过图像采集装置获取图像，以基准发光模块在图像采集机构上形成的图块作为参考图块，其他图块作为待比较图块，每个图块对应一个发光模块的输出波长的激光；以参考图块作为参照，获取各个待比较图块各自对应的预设图块范围；将待比较图块与各自对应的预设图块范围比较；判断待比较图块是否落入各自对应的预设图块范围内；若待比较图块超出各自对应的预设图块范围外，调整该待比较图块对应的发光模块中布拉格的锁定波长，以使该待比较图块落入各自对应的预设图块范围内。以参考模块在图像采集机构上的图块来计算出待比较模块在图像采集机构上的图块的预设图块范围，再比较图像采集到的待比较模块的图块与预设图块范围，判断是否存在偏差也即是否落入预设图块范围，利用偏差与经色散元件后的衍射角之间的关系，再根据光栅方程转化为波长，利用波长与布拉格光栅温度的关系，转化为温差，通过调整布拉格光栅的温度来调整锁定波长；合束方法简单，调整快速有效。
附图说明
为了更清楚地说明本申请具体实施方式或现有技术中的技术方案，下面将对具体实施方式或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图是本申请的一些实施方式，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1为本申请的发光模块直接输出激光且合束元件为透射式光栅的结构图；
图2为本申请的发光模块直接输出激光且合束元件为反射式光栅的结构图；
图3为本申请的发光模块的激光耦合进光纤实现尾纤输出且合束元件为透射式光栅的结构图；
图4为本申请的发光模块的激光耦合进光纤实现尾纤输出且合束元件为反射式光栅的结构图；
图5为本申请的发光模块结构图；
图6为本申请的发光模块光路原理图；
图7为本申请的温控元件结构图；
图8为本申请的发光模块在图像采集机构上的图块的理论位置范围结构示意图；
图9为本申请的发光模块在图像采集机构上的待比较图块发生左偏时的结构示意图；
图10为本申请的发光模块在图像采集机构上的待比较图块发生右偏时的结构示意图。
附图标记说明：
1-发光模块；100-基准发光模块；101-10N-发光模块；101’-10N’-发光模块；11-激光单元；111-11n-激光器单管芯片；12-快轴准直透镜；121-12n-快轴准直透镜；13-慢轴准直透镜；131-13n-慢轴准直透镜；14-反射镜；141-14n-反射镜；15-出光孔；16-布拉格光栅；17-温控装置；18-导热玻璃；19-导线；
2-聚焦光学元件；
3-合束元件；
4-分光元件；
5-色散元件；
6-变换光学元件；
7-图像采集机构；
8-光纤。
具体实施方式
下面将结合附图对本申请的技术方案进行清楚、完整地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
在本申请的描述中，需要说明的是，术语“中心”、“上”、“下”、“左”、“右”、“竖直”、“水平”、“内”、“外”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请的限制。此外，术语“第一”、“第二”、“第三”仅用于描述目的，而不能理解为指示或暗示相对重要性。
在本申请的描述中，需要说明的是，除非另有明确的规定和限定，术语“安装”、“相连”、“连接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是机械连接，也可以是电连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以具体情况理解上述术语在本申请中的具体含义。
此外，下面所描述的本申请不同实施方式中所涉及的技术特征只要彼此之间未构成冲突就可以相互结合。
实施例1
本实施例的VBG光栅外腔激光器模块合束装置，如图1至图4所示，包括多个发光模块1、一个聚焦光学元件2、一个合束元件3、一个分光元件4、一个色散元件5、一个变换光学元件6、一个图像采集机构7和温控装置17，其中多个发光模块1阵列间隔布置用于发射不同波长的激光，激光入射至布拉格光栅16上实现波长锁定，其中位于最中间的发光模块(图中对应地波长为λ 0的发光模块)作为基准发光模块100，发射的激光的波长为λ 0，其他发光模块1对称设置在该基准发光模块100的上下两侧，各发光模块1之间的间隔相等，基准发光模块100的输出光水平入射至聚焦光学元件2的中心位置并水平入射至合束元件3上；发光模块1的输出光经布拉格光栅16锁定后以锁定波长λ n(n＝±1,±2,±3,...,±N)输出；一个聚焦光学元件2设置在所有发光模块1的输出光路上，用于对所有发光模块1发射的不同锁定波长的激光进行聚焦；一个合束元件3设置在聚焦光学元件2的聚焦位置处，将不同发光模块1发射的不同波长的输出光进行合束形成合束光后以相同的衍射角α n输出；分光元件4设置在合束元件3的衍射光路上，分光元件4将合束光分为反射光和透射光，其中一部分合束光透过分光元件4进行输出，另一部分合束光反射至反射光光路上的色散元件5，色散元件5将合束光分散为与聚焦光学元件2和合束元件3之间的各个波长的激光相对位置关系一致的分散光，也即各发光模块1的输出光经色散元件5后的出射角β n与其在合束元件3上的入射 角α n构成一一对应关系，比如，第1个发光模块以入射角α 1入射至合束元件3上，以出射角β 1从色散元件出射，第N个发光模块以入射角α N入射至合束元件3上，以出射角β N从色散元件出射；各发光模块1的输出光经合束元件3后再经色散元件5的色散作用后的光束在变换光学元件6的变换作用下形成平行间隔光，并在变换光学元件6出射面的图像采集机构7上形成与各个发光模块1的输出光波长对应的图块。本申请的发光模块为两个、三个、四个、五个等等，具体数量不做限定，其中一个作为基准模块，其他的发光模块以基准模块为参照，对称设置在基准模块的上下两侧，也可以为其他发光模块全部设置在基准模块的上侧或全部在下侧，具体不做限定，只要保证基准模块的输出光正对聚焦光学元件的中心即可；为了便于描述区分，分别被分别标记为100,101-10N，101’-10N’，每个发光模块1经布拉格光栅16进行波长锁定后的中心波长不同；比如，基准发光模块100的输出光经布拉格光栅16进行波长锁定后的中心波长为λ 0，发光模块101的输出光中心波长为λ 1，发光模块101’的输出光中心波长为λ -1，发光模块10N的输出光中心波长为λ N，发光模块10N’的输出光中心波长为λ -N，其他发光模块的中心波长依次类推。
本申请的布拉格光栅16为垂直反射式布拉格光栅，反射率在10％～30％的范围内，反射带宽小于1nm，温漂系数约为0.01nm/℃，温度与波长呈线性关系，满足以下关系式：
λ(T)＝λ 0+0.01*(T-T 0)
其中λ(T)是在温度为T时的中心波长；λ 0是在温度为T 0时的中心波长；0.01是波长随温度漂移系数，单位是nm/℃；
其具体结构和工作原理在此不做详细描述和限定，可以根据实际需要进行选择。
本申请的分光元件4可以为现有的非偏振型平面分光镜，也可以为立方体型，具体不做限定，主要目的在于将发光模块发射的输出光分成反射光和透射光两路光束，其具体结构和工作原理在此不做描述和限定，可以根据实际需要进行选择。
如图5所示，本申请的发光模块1为方形盒状的激光器模块，内设有用于发射激光的激光单元11，激光单元11为激光器单管芯片，在快轴方向上呈台阶排布设置，内设有一个凹槽口，凹槽口设有两排多级台阶，一排多级台阶上对应设有个多个激光器单元11，另一排多级台阶上对应设有多个准直系统和反射镜14，发光模块1上一侧(如图1中所示的左上角)设有用于出射激光的出光孔15，多个反射镜14的反射面朝向出光孔15设置，在反射镜14与出光孔15之间设置布拉格光栅16，布拉格光栅16通过加热元 件与温控装置17连接。每个发光模块1中的多个激光器单元11在慢轴方向也即水平方向并排排列，沿快轴方向即垂直方向台阶排列；具体的，如图5所示，每个发光模块1包括多个激光器单管芯片111-11n，多个激光器单管芯片111-11n一一对应设置在多级台阶上，呈台阶阵列排布且相邻两个激光器单管芯片的高度差相等；每个激光器单管芯片的出射面依次设有准直系统和反射镜，准直系统包括沿一个激光器单管芯片的出射面依次设置的一个用于压缩激光快轴方向的发散角的快轴准直透镜和一个用于压缩激光慢轴方向的发散角的慢轴准直透镜，反射镜14设置在慢轴准直透镜的出射面，且多个反射镜14对应设置在另一排多级台阶上，也呈台阶排布设置，相邻两个反射镜14的高度差也相等；多个激光器单管芯片发出的光分别经准直系统完全准直后，在对应地反射镜的作用下于快轴方向上进行空间合束，可以在较小的空间内设置较多数量的激光器单管芯片。反射镜14为45度反射镜且垂直于水平面设置，与快轴准直透镜和慢轴准直透镜组成的准直系统的光轴成45°，多个反射镜14设置实现多个半导体激光单管芯片出射的激光在空间上合束，经过反射镜14作用后形成空间合束光束，空间合束光束入射到布拉格光栅16，一部分空间合束光透过布拉格光栅16作为输出光，另一部分作为反馈光，回到激光器单管芯片内部，用于对半导体激光单管芯片出射的激光的波长进行锁定，布拉格光栅16与激光器单管芯片构成外腔，反馈光在芯片内部形成模式竞争，实现波长选择，使得发光模块1以锁定波长输出。作为可替换实施例，本申请的激光器单管芯片的前腔面镀有减反膜芯片，但不做具体限定。
本申请的快轴准直透镜12和慢轴准直透镜13为现有市场上的准直透镜，其具体结构和工作原理在此不做描述和限定，可以根据实际需要进行选择。作为可替换实施例，本申请的快轴准直透镜12和慢轴准直透镜13均镀有减反膜，由于减少光束反射，相对于激光器芯片的光束波长，镀膜后的透过率应在99％以上，也可以不做限定。
本申请的发光模块1的光路原理如图6所示，激光器单管芯片111发出的激光在快轴方向上被快轴准直透镜121准直，快轴方向被准直的光到达慢轴准直透镜131，快轴方向上被准直的光被慢轴准直透镜131在慢轴方向上准直，成为完全准直光，完全准直光被慢轴准直透镜131出射面的反射镜141反射后从模块中发出；与激光器单管芯片111存在台阶高度差的激光器单管芯片112发出的光经快轴准直透镜122和慢轴准直透镜132准直后到达反射镜142，反射镜142与反射镜141也存在台阶高度差，激光器单管芯片112发出的光经反射镜142发射后从反射镜141上方通过，实现与激光器单管芯片111发出的光在快轴方向的合束；依次类推，多个台阶排布设置的激光器单管芯片发出 的激光在空间上进行合束形成发光模块1的输出光。每个发光模块1均包括多个激光器单管芯片，多个激光器单管芯片呈台阶高度差设置，在较小的空间内集成更多的半导体激光单管，可以将更多数量的单管的光束进行空间合束后直接输出也可以通过非球面聚焦透镜(未图示)耦合进光纤8构成尾纤发光模块，从而具有更大的输出功率。
本申请的合束元件3为光栅，朝向傅里叶变换透镜的凸面设置，合束元件3偏振应与发光模块发出的光束偏振一致；光栅的衍射效率在相应的偏振方向上应在90％以上；光栅的中心波长在λ 0～λ n范围内；光栅相对于光轴以闪耀角放置；可以为透射式光栅也可以为反射式光栅。
本申请的色散元件5为光栅，光栅的中心波长在λ 0～λ n范围内；可以为透射式光栅也可以为反射式光栅，其结构和工作原理在此不做描述和限定，可以根据实际需要进行选择。
本申请的合束元件3和色散元件4相对于光轴以各自的闪耀角放置；比如，各发光模块1的输出光经过合束元件3合束的合束光与合束元件3以衍射角α Littrow出射，该出射光束经过分光元件4作用后的一部分光束以衍射角β Littrow入射到色散元件5上；两个衍射角可以相等，也可以不相等，主要取决于合束元件3和色散元件5是否为同一光栅，如果为同一光栅，两者的衍射角相等；如果不为同一光栅时，则不相等；对应地，合束元件3和色散元件5为同一光栅时，各发光模块1的输出光入射至合束元件3的入射角α n与从色散元件5出射的出射角β n相等；如果不为同一光栅，则不相等。
本申请的合束元件3和色散元件5可以同时为透射式光栅，也可以同时为反射式光栅，还可以其中一个透射式光栅，另外一个为反射式光栅，具体选择不做限定，只要能实现合束之后再色散即可；如图1至图4所示，位于基准模块100上方的发光模块的输出光经过合束元件3、分光元件4和色散元件5后，出射方向向右，而位于基准模块100下方的发光模块的输出光经过合束元件3、分光元件4和色散元件5后，出射方向向左。
本申请的聚焦光学元件2为傅里叶变换透镜，傅里叶变换透镜一面平一面凸的柱面透镜，平的一面朝向发光模块1设置，凸的一面背向发光模块1设置朝向合束元件3设置。其具体结构和工作原理等在此不做描述和限定，可以根据实际需要进行选择不同焦距的傅里叶变换透镜。比如由上述公式得知，为了在相同的谱宽范围内获得更多的合束单元可以选择长焦距的傅里叶变换透镜，具体情况可以根据实际需要进行选择。可选的，本申请的聚焦光学元件2也可以为其他的普通的聚焦光学元件，只要能实现将不同的发光模块发射的不同波长的激光进行聚焦入射至合束元件即可。
本申请的变换光学元件6为现有的普通变换柱面透镜，只要能满足将经色散元件5分散后的不同出射角的子束变换为平行子束即可，具体结构和原理不做描述和限定。
本申请的温控装置17，包括调温元件，与布拉格光栅16连接；温度检测元件(未图示)，用于检测布拉格光栅16的温度；控制器(未图示)，与调温元件和温度检测元件均电连接，控制器根据温度检测元件的检测信号，控制加热元件的升温或降温；调温元件包括加热元件或制冷元件；当需要升温时，开启加热元件；当需要降温时，开启制冷元件。如图7所示，本申请的温控装置16为现有市场上的常见的TEC温度控制装置，其具体结构和工作原理在此不做描述和限定，通过导热玻璃18与布拉格光栅16接触连接，通过导线19与控制器电连接，控制器与图像采集机构7连接，图像采集机构7与布拉格光栅16之间形成闭环连接；通过图像采集机构7采集到发光模块1的输出光在图像采集机构上的成像图块，与预设图块范围进行比较，判断是否存在偏差，若存在偏差，控制器将偏差转化对应发光模块1发射的激光的波长偏差，再转化为对应发光模块1的布拉格光栅16的温度偏差，根据布拉格光栅16的温度与波长关系，得到该发光模块1的布拉格光栅16与预设布拉格光栅16的温度差值，进而通过温控装置17进行升降温度来调整布拉格光栅16的温度，使得对应地发光模块1发射的激光的波长达到预设波长范围，实现波长锁定。
本申请的图像采集机构7为CCD，比如线阵CCD或面阵CCD等，不做特别限定，当然也可以为其他现有技术中的图像采集装置，其具体结构和工作原理，在此不做限定和描述。
为了在合束元件3处也即光栅能够实现合束，根据光栅的色散特性，需将第n个发光模块的中心波长锁定在λ n，第n个发光模块的锁定波长λ n与基准参考模块100对应的锁定波长λ 0之间满足以下几何关系：
Figure PCTCN2020093137-appb-000001
其中，λ 0为基准发光模块的中心波长，λ n为第n个发光模块中心波长，d为光栅的光栅周期，p为发光模块的间隔，f TL为聚焦光学元件的焦距，α Ltirrow为光栅闪耀角；
上述公式的推导过程如下：
根据光栅方程，波长和入射角满足以下几何关系
λ n＝d(sinα n+sinα Littrow),n＝±1,±2,±3,...,±N    (1)
式中λ n为第n个发光模块的输出光的中心波长，α n为第n个发光模块的输出光的入射至合束元件3的入射角，α Littrow为合束元件3的光栅闪耀角。
设p为相邻发光模块间的间距，f TL为聚焦光学元件的有效焦距，则根据透镜变换的几何关系，第n个发光模块的输出光入射至合束元件3的入射角为
Figure PCTCN2020093137-appb-000002
联立(1)和(2)得到
Figure PCTCN2020093137-appb-000003
应用中一般满足f TL＞＞n·p，因此可取近似
Figure PCTCN2020093137-appb-000004
则(3)式化简为
Figure PCTCN2020093137-appb-000005
两边分别对λ n和n求一阶导数，得到相邻发光模块的输出光的中心波长的波长间隔
Figure PCTCN2020093137-appb-000006
一般光栅的闪耀角较大，应用中不仅满足f TL＞＞n·p，且同时满足
Figure PCTCN2020093137-appb-000007
此时公式(5)可化简为
Figure PCTCN2020093137-appb-000008
由式(5)和(6)得需将第n个发光模块的输出光的中心波长锁定在λ n处，锁定波长的计算为
λ n＝λ 0+n·△λ       (7)
即
Figure PCTCN2020093137-appb-000009
由上述公式得知，合束波长间隔与光栅周期、发光模块间隔成正比，与聚焦光学元件的焦距成反比；因此，可以通过选择长焦距聚焦光学元件方法来降低合束波长间隔，从而可以在相同的谱宽范围内容纳更多的合束单元，从而提供系统功率，增加系统的输出光束亮度。
参见图1和图3，此系统的合束元件3为透射式光栅，透射式光栅相对于光轴以闪耀角α Littrow放置，n个发光模块的n个激光器芯片11发射的激光经准直系统完全准直后经反射镜反射在快轴方向上进行空间合束后到达布拉格光栅16，经布拉格光栅16锁定波长后从出光孔15输出到傅里叶变换透镜，经变换后将不同发光模块1发射的不同波长的激光的位置信息转化为角度信息后以不同的入射角α n聚焦入射到透射式光栅表面， 在透射式光栅的作用下，不同子束以相同的衍射角α Littrow(合束元件3的光栅闪耀角)输出，形成合束光，合束光照射到分光元件4表面，在分光元件4的作用下分成反射光和透射光，透射光透过分光元件4输出，反射光经分光元件4反射后以入射角β Littrow(色散元件5的光栅闪耀角)入射至光栅表面；在光栅的色散作用下重新分散成不同角度的子束，各子束以β n输出，入射至变换光学元件6，在变换光学元件6的作用下将各子束形成平行光输出并垂直成像到CCD上，在CCD上形成等间隔的图块。本申请的透射式光栅为现有市场上的透射式光栅，其具体结构和工作原理在此不做限定和描述，可以根据实际需要进行选择。
参见图2和图4，此系统的合束元件3为反射式光栅，反射式光栅相对于光轴以闪耀角α Littrow放置，n个发光模块1的n个激光器芯片11发出的激光经准直系统完全准直后经反射镜反射在快轴方向上进行空间合束后到达布拉格光栅16，经布拉格光栅16锁定波长后从出光孔15输出到傅里叶变换透镜，经傅里叶变换将不同发光模块发射的不同波长的激光的位置信息转化为角度信息后，以不同的入射角α n聚焦入射到反射式光栅表面，在反射式光栅的作用下，各光束以相同的反射角α Littrow(合束元件的光栅闪耀角)输出，形成合束光，合束光反射到分光元件4表面，在分光元件4的作用下分成反射光和透射光，透射光透过分光元件输出，反射光经分光元件4反射后同样以β Littrow(色散元件的光栅闪耀角)入射至光栅表面，在光栅的色散作用下重新分散成不同角度的子束，各子束以β n输出，入射至变换光学元件6，在变换光学元件6的作用下将各子束形成平行光输出并垂直成像到CCD上，在CCD上形成等间隔的图块。本申请的反射式光栅为现有市场上的反射式光栅，其具体结构和工作原理在此不做限定和描述，可以根据实际需要进行选择。
上述的β Littrow与α Littrow在合束元件3和色散元件5为同一光栅时相等，在不为同一光栅时不等；同理，上述的β n与α n合束元件3和色散元件5为同一光栅时相等，在不为同一光栅时不等。
实施例2
本实施的合束方法，基于实施例1中的布拉格光栅外腔激光器模块合束装置，如图1至图10所示，包括以下步骤：
获取图像，图像包括参考图块及若干个待比较图块，其中参考图块对应于基准发光模块100(如图1中标示λ 0的发光模块)的输出波长(λ 0)的激光，待比较图块与其他的发光模块(如图1中标示λ 1-λ N和λ -1-λ -N的发光模块)的输出波长的激光一一对应；
基于参考图块，获取各个待比较图块各自对应的预设图块范围；
将任一待比较图块与各自对应的预设图块范围比较；
判断待比较图块是否落入各自对应的预设图块范围内；
若待比较图块超出各自对应的预设图块范围外，调整该待比较图块对应的发光模块中布拉格光栅的锁定波长，以使该待比较图块落入各自对应的预设图块范围内。
在判断待比较图块是否落入各自对应的预设图块范围内的步骤中，
待比较图块与各自对应的预设图块的偏差不大于2个像素点，则表明该待比较图块落入各自对应的预设图块范围内。
在若待比较图块超出各自对应的预设图块范围外，调整该待比较图块对应的发光模块中布拉格光栅的锁定波长的步骤中，
通过调整该待比较图块对应的发光模块中布拉格光栅的温度，以调整该布拉格光栅的锁定波长。
在基于参考图块，获取各个待比较图块各自对应的预设图块范围的步骤中，参考图块与其相邻的预设图块之间的间距，与任意相邻的预设图块之间的间距相等。
由于各发光模块的输出光在图像采集机构上的成像的图块不是一个点，是一个区域，反应到处理图像上，上述的预设图块范围可以用各待比较图块与参考图块的位置间隔来描述。
由上述波长锁定公式可知，第n个发光模块1的输出光入射到合束元件3上的入射角为
Figure PCTCN2020093137-appb-000010
经过合束元件3合束的合束光与合束元件以衍射角α Littrow出射，该出射光束经过分光元件4作用后的一部分光束以β Littrow入射到色散元件5上，根据光栅衍射特性，波长为λ n(n＝±1,±2,±3,...,±N)的光束，假设变换光学元件6的焦距为f,在图像采集机构7上的图块的间隔为p 0，则根据几何关系
Figure PCTCN2020093137-appb-000011
计算得到
Figure PCTCN2020093137-appb-000012
待比较发光模块(如图中标示输出波长为λ 1-λ N和λ -1-λ -N的发光模块)相对于基准发光模块100(如图中标示输出波长为λ 0的发光模块)上下对称排列，待比较模块的输出光在图像采集机构7上形成的待比较图块相对于基准参考模块100的输出光在图像 采集机构7上的参考图块是左右对称的；由上述公式(7)得知发光模块1的输出光的锁定波长从上往下以△λ递减，对应地在图像采集机构7上的对应图块的对应波长从左到右也以△λ逐渐递减，由于相邻图块的对应波长是等间隔的，因此，相邻图块之间的间隔也是相等的；
由上述公式(10)可以计算得到相邻图块之间的理论间隔值p 0，由此，可以得到每个待发光模块在图像采集机构7上的待比较图块的预设图块范围；为了减小误差，我们以锁定波长为λ 0的发光模块作为参考，其在图像采集机构7上的图块作为参考图块，待比较图块与参考图块之间的理论间隔预存在于控制器内。
如图8所示为发光模块的输出光在图像采集机构上成像的图块均在理论位置，即每个发光模块的输出光在图像采集机构上成像的图块均在预设图块范围内。
图像采集机构7采集到各发光模块1的图块的实际图像信息，图像采集机构对实际图像信息进行处理，将图像信息转化为位置信息，得到处理图像，图像采集机构7将采集到的各发光模块1的图块的实际位置信息反馈给控制器，控制器分析得到各待比较发光模块的待比较图块相对于参考图块之间的实际间隔；由采集到的参考图块的实际图块范围，控制器进行计算分析得到各待比较模块的预设图块范围，控制器将各待比较发光模块的待比较图块的实际图块与其对应的预设图块范围进行比较，判断实际图块是否落入预设图块范围内，即与预设图块范围是否存在偏差，控制器再将图块偏差转化为图块对应的发光模块的输出光的波长偏差，再根据布拉格光栅16的温漂特性将波长偏差转换成温度偏差，继而得到温度该升高还是该降低以及升高和降低的具体值，然后控制器再控制温控装置17调节布拉格光栅16的温度实现调整实现多发光模块的合束。
假设控制器读取出的第n个发光模块的待比较图块与其预设图块范围存在偏差，假设此偏差为L(左偏为负值，如图9所示；右偏为正值，如图10所示)，由光栅的特性可知，该待比较发光模块1的输出光在色散元件5处的衍射角设为β n’，根据几何关系
Figure PCTCN2020093137-appb-000013
根据光栅方程，其锁定波长为
λ n＝d(sinβ Littrow+sinβ n')   (13)
此时计算得到的是该待比较图块对应的发光模块的实际锁定波长，控制器再比较实际锁定波长和理论计算的该发光模块的锁定波长(由上述公式(8)计算得到)；最 后根据上述实施例1中的布拉格光栅16的温度和波长的几何关系，由波长偏差转化为温度偏差，根据计算得到的发生偏差的待比较图块对应的发光模块1的实际锁定波长，得到该发光模块1的布拉格光栅16的实际温度，继而与预设温度进行比较，得到温度该升高还是该降低以及升高和降低的具体值；
最后通过温控装置17进行升温或降温来调节布拉格光栅16的温度来调节对应发光模块1的锁定波长；温度检测元件检测到布拉格光栅16的实际温度，控制器根据计算分析得到的温差值，控制加热或制冷元件开启，通过导热玻璃将热量传导给布拉格光栅16；当温度检测元件检测到布拉格光栅16的温度达到预设值时，控制器控制加热或制冷元件关闭；导热元件与布拉格光栅接触连接发生热交换，即使关闭加热或制冷元件，布拉格光栅与导热玻璃之间仍会继续发生热交换，因此布拉格光栅的锁定波长与预设值之间可能会存在误差，从而在图像采集机构7上的图块的位置也会存在偏差，但是只要该发光模块1在图像采集机构7上的图块范围与预设图块范围的偏差在两个像素范围内，即表明该发光模块的中心波长已锁定。
显然，上述实施例仅仅是为清楚地说明所作的举例，而并非对实施方式的限定。对于所属领域的普通技术人员来说，在上述说明的基础上还可以做出其它不同形式的变化或变动。这里无需也无法对所有的实施方式予以穷举。而由此所引伸出的显而易见的变化或变动仍处于本申请创造的保护范围之中。

Claims (10)

  1. 一种布拉格光栅外腔激光器模块合束装置，包括至少两个间隔且并排布置的发光模块(1)，任一所述发光模块(1)包括激光单元(11)，及用于接收所述激光单元(11)发射出的激光的布拉格光栅(16)；其中，一个所述发光模块(1)作为基准发光模块(100)；设在所有所述发光模块(1)的输出光路上的聚焦光学元件(2)；设在所述聚焦光学元件(2)的输出光路的聚焦位置处的合束元件(3)；其特征在于，还包括
    分光元件(4)，设在所述合束元件(3)的输出光路上；
    色散元件(5)，设在所述分光元件(4)的任一输出光路上，用于将合束光分散为与所述聚焦光学元件(2)和所述合束元件(3)之间的各个波长的激光相对位置关系一致的分散光；
    变换光学元件(6)，设在所述色散元件(5)的输出光路上，用于将所述分散光透射为平行光；
    图像采集机构(7)，设在所述变换光学元件(6)的输出光路上，用于采集所述变换光学元件(6)的输出光路上的平行光照射的图块。
  2. 根据权利要求1所述的一种布拉格光栅外腔激光器模块合束装置，其特征在于，所述发光模块(1)为至少三个，所有所述发光模块(1)等间距并列排布。
  3. 根据权利要求1或2所述的一种布拉格光栅外腔激光器模块合束装置，其特征在于，
    所述合束元件(3)和所述色散元件(5)均为光栅。
  4. 根据权利要求3所述的一种布拉格光栅外腔激光器模块合束装置，其特征在于，
    所述合束元件(3)和所述色散元件(5)均为透射式光栅或反射式光栅，所述合束光经所述合束元件(3)的衍射角为所述合束元件(3)的光栅闪耀角，所述合束光入射至所述色散元件(5)的入射角为所述色散元件(5)的光栅闪耀角。
  5. 根据权利要求1-4任一项所述的一种布拉格光栅外腔激光器模块合束装置，其特征在于，任一所述发光模块还包括设在所述布拉格光栅(16)的输出光路上的光纤(8)。
  6. 根据权利要求1-5中任一项所述的一种布拉格光栅外腔激光器模块合束装置，其特征在于，还包括温控装置(17)，所述温控装置(17)包括
    调温元件，设在所述布拉格光栅(16)上；
    温度检测元件，用于检测所述布拉格光栅(16)的温度；
    控制器，与所述调温元件和所述温度检测元件均电连接，所述控制器根据所述温度 检测元件的检测信号，控制所述调温元件的升温或降温。
  7. 一种基于权利要求1-6任一项所述的布拉格光栅外腔激光器模块合束装置的合束方法，其特征在于，包括以下步骤：
    获取图像，所述图像包括参考图块及若干个待比较图块，其中所述参考图块对应于所述基准发光模块的输出波长的激光，所述待比较图块与其他的所述发光模块的输出波长的激光一一对应；
    基于所述参考图块，获取各个待比较图块各自对应的预设图块范围；
    将任一所述待比较图块与各自对应的预设图块范围比较；
    判断所述待比较图块是否落入各自对应的预设图块范围内；
    若待比较图块超出各自对应的预设图块范围外，调整该所述待比较图块对应的所述发光模块中布拉格光栅的锁定波长，以使该所述待比较图块落入各自对应的预设图块范围内。
  8. 根据权利要求7所述的布拉格光栅外腔激光器模块合束装置的合束方法，其特征在于，在判断所述待比较图块是否落入各自对应的预设图块范围内的步骤中，
    待比较图块与各自对应的预设图块的偏差不大于2个像素点，则表明所述待比较图块落入各自对应的预设图块范围内。
  9. 根据权利要求7或8所述的布拉格光栅外腔激光器模块合束装置的合束方法，其特征在于，
    在所述若待比较图块超出各自对应的预设图块范围外，调整该所述待比较图块对应的所述发光模块中布拉格光栅的锁定波长的步骤中，
    通过调整该所述待比较图块对应的所述发光模块中布拉格光栅的温度，以调整该所述布拉格光栅的锁定波长。
  10. 根据权利要求7-9中任一项所述的布拉格光栅外腔激光器模块合束装置的合束方法，其特征在于，
    在基于所述参考图块，获取各个待比较图块各自对应的预设图块范围的步骤中，所述参考图块与其相邻的预设图块之间的间距，与任意相邻的预设图块之间的间距相等。
PCT/CN2020/093137 2019-06-27 2020-05-29 一种布拉格光栅外腔激光器模块合束装置及合束方法 WO2020259198A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US17/622,964 US11631966B2 (en) 2019-06-27 2020-05-29 Beam combining device and beam combining method for Bragg grating external-cavity laser module

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201910569713.2A CN110323672B (zh) 2019-06-27 2019-06-27 一种布拉格光栅外腔激光器模块合束装置及合束方法
CN201910569713.2 2019-06-27

Publications (1)

Publication Number Publication Date
WO2020259198A1 true WO2020259198A1 (zh) 2020-12-30

Family

ID=68120501

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/093137 WO2020259198A1 (zh) 2019-06-27 2020-05-29 一种布拉格光栅外腔激光器模块合束装置及合束方法

Country Status (3)

Country Link
US (1) US11631966B2 (zh)
CN (1) CN110323672B (zh)
WO (1) WO2020259198A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115096177A (zh) * 2022-01-06 2022-09-23 同济大学 一种用子光束位置监测激光合束系统光束的装置及方法

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110323672B (zh) * 2019-06-27 2020-12-01 苏州长光华芯光电技术有限公司 一种布拉格光栅外腔激光器模块合束装置及合束方法
CN110854674A (zh) * 2019-10-31 2020-02-28 苏州长光华芯光电技术有限公司 一种半导体激光器光栅外腔光谱合束装置
CN110854654B (zh) * 2019-11-18 2021-06-15 无锡锐科光纤激光技术有限责任公司 一种半闭环控制激光器
CN112652950B (zh) * 2020-11-26 2021-12-14 苏州长光华芯光电技术股份有限公司 一种波长锁定半导体激光器系统
CN112531462B (zh) * 2020-12-04 2021-12-03 苏州长光华芯光电技术股份有限公司 一种布拉格光栅外腔半导体激光器模块合束装置
CN112993747B (zh) * 2021-02-08 2022-05-27 苏州长光华芯光电技术股份有限公司 一种波长锁定半导体激光器系统
CN113644544B (zh) * 2021-08-11 2022-09-06 苏州长光华芯光电技术股份有限公司 一种波长锁定半导体激光器系统
CN114243452A (zh) * 2022-02-24 2022-03-25 深圳市星汉激光科技股份有限公司 一种半导体激光器的互锁光路
CN115128820B (zh) * 2022-08-30 2022-11-08 中国科学院长春光学精密机械与物理研究所 啁啾反射式体布拉格光栅反馈的光谱合束装置及方法
CN115995756A (zh) * 2023-03-23 2023-04-21 苏州长光华芯半导体激光创新研究院有限公司 一种波长锁定系统和波长锁定方法
JP7387077B1 (ja) * 2023-04-24 2023-11-27 三菱電機株式会社 レーザ装置およびレーザ加工機

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030206336A1 (en) * 2002-05-02 2003-11-06 Fujitsu Limited Variable wavelength light source apparatus and optical amplifier using same
CN1658453A (zh) * 2004-02-18 2005-08-24 中国科学院半导体研究所 混合集成的可调谐半导体激光器
CN103078253A (zh) * 2012-12-28 2013-05-01 西安炬光科技有限公司 一种窄光谱高功率半导体激光器耦合装置及方法
CN103904557A (zh) * 2014-03-25 2014-07-02 中国科学院半导体研究所 激光器合束装置和方法
CN104901149A (zh) * 2015-05-05 2015-09-09 中国科学院上海光学精密机械研究所 基于三块衍射光栅的光谱合束系统
CN105140769A (zh) * 2015-09-28 2015-12-09 湖北航天技术研究院总体设计所 一种光谱合成光束重叠检测调整装置
CN108254930A (zh) * 2018-03-19 2018-07-06 谱诉光电科技（苏州）有限公司 色散分光型滤光方法及装置
CN110323672A (zh) * 2019-06-27 2019-10-11 苏州长光华芯光电技术有限公司 一种布拉格光栅外腔激光器模块合束装置及合束方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8526110B1 (en) * 2009-02-17 2013-09-03 Lockheed Martin Corporation Spectral-beam combining for high-power fiber-ring-laser systems
DE112011101288T5 (de) * 2010-04-12 2013-02-07 Lockheed Martin Corporation Strahldiagnostik- und Rückkopplungssystem sowie Verfahren für spektralstrahlkombinierteLaser
CN103441419A (zh) * 2013-08-30 2013-12-11 中国科学院上海光学精密机械研究所 基于达曼光栅的光纤激光全光反馈被动相干合束系统
US11646549B2 (en) * 2014-08-27 2023-05-09 Nuburu, Inc. Multi kW class blue laser system

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030206336A1 (en) * 2002-05-02 2003-11-06 Fujitsu Limited Variable wavelength light source apparatus and optical amplifier using same
CN1658453A (zh) * 2004-02-18 2005-08-24 中国科学院半导体研究所 混合集成的可调谐半导体激光器
CN103078253A (zh) * 2012-12-28 2013-05-01 西安炬光科技有限公司 一种窄光谱高功率半导体激光器耦合装置及方法
CN103904557A (zh) * 2014-03-25 2014-07-02 中国科学院半导体研究所 激光器合束装置和方法
CN104901149A (zh) * 2015-05-05 2015-09-09 中国科学院上海光学精密机械研究所 基于三块衍射光栅的光谱合束系统
CN105140769A (zh) * 2015-09-28 2015-12-09 湖北航天技术研究院总体设计所 一种光谱合成光束重叠检测调整装置
CN108254930A (zh) * 2018-03-19 2018-07-06 谱诉光电科技（苏州）有限公司 色散分光型滤光方法及装置
CN110323672A (zh) * 2019-06-27 2019-10-11 苏州长光华芯光电技术有限公司 一种布拉格光栅外腔激光器模块合束装置及合束方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115096177A (zh) * 2022-01-06 2022-09-23 同济大学 一种用子光束位置监测激光合束系统光束的装置及方法
CN115096177B (zh) * 2022-01-06 2023-08-04 同济大学 一种用子光束位置监测激光合束系统光束的装置及方法

Also Published As

Publication number Publication date
CN110323672A (zh) 2019-10-11
CN110323672B (zh) 2020-12-01
US20220271501A1 (en) 2022-08-25
US11631966B2 (en) 2023-04-18

Similar Documents

Publication Publication Date Title
WO2020259198A1 (zh) 一种布拉格光栅外腔激光器模块合束装置及合束方法
WO2018010224A1 (zh) 一种激光合束装置
US9391713B2 (en) High brightness dense wavelength multiplexing laser
US7873091B2 (en) Laser diode illuminator device and method for optically conditioning the light beam emitted by the same
JP2009529220A (ja) 発光ダイオード投影システム
US20150316234A1 (en) Light source, light source unit, and light source module using same
JP6157194B2 (ja) レーザ装置および光ビームの波長結合方法
CN104049445A (zh) 发光装置及投影系统
WO2016035349A1 (ja) レーザー光学装置及び画像投影装置
CN102208753A (zh) 多波长联合外腔半导体激光器
CN214044331U (zh) 一种蓝光多单管平行双光栅外腔反馈合束装置
CN103197422A (zh) 一种基于双光栅的波长可调谐激光相干合束系统
US7769068B2 (en) Spectral-narrowing diode laser array system
CN105071196A (zh) 一种窄线宽合束模块及具有该模块的多波长拉曼激光器
CN113644544B (zh) 一种波长锁定半导体激光器系统
Romanova et al. Design of an optical illumination system for a tunable source with acousto-optical filtering
CN102868089B (zh) 利用单光栅外腔反馈实现多半导体激光合束的装置及方法
US20210184429A1 (en) Laser device
CN111326952A (zh) 基于片上调控半导体激光芯片的光谱合束装置
JP2008511131A (ja) ダイオードレーザ
CN111694160A (zh) 一种激光光源装置
JP2014120621A (ja) 半導体レーザ装置
CN113948970A (zh) 一种基于后腔外腔光谱调控的光谱合束装置
CN219086442U (zh) 自适应反馈等光程蓝光半导体激光单管阵列光谱合束装置
CN114465088B (zh) 一种波长锁定系统

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20831726

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20831726

Country of ref document: EP

Kind code of ref document: A1

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 25.05.2022)

122 Ep: pct application non-entry in european phase

Ref document number: 20831726

Country of ref document: EP

Kind code of ref document: A1