CN112803228B - Vortex light beam generation method based on spiral line arrangement phase-locked fiber laser array - Google Patents
Vortex light beam generation method based on spiral line arrangement phase-locked fiber laser array Download PDFInfo
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- 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
- H01S3/06—Construction or shape of active medium
- H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
- H01S3/067—Fibre lasers
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/09—Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for
- G02B27/0927—Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/09—Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for
- G02B27/0938—Using specific optical elements
- G02B27/0977—Reflective elements
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- 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
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/10053—Phase control
Abstract
The invention provides a vortex beam generation method based on a spiral line arrangement phase-locked fiber laser array, which utilizes a phase control technology to compensate dynamic phase noise of a fiber laser array system and stably controls the phase difference between light beams of an emitting surface unit to be 0 or integral multiple of 2 pi; and the unit beams of the emitting surface in the optical fiber laser array system are arranged in a spiral line type, so that the optical paths of the unit beams at different spatial positions of the emitting surface transmitted to the same spatial position of the target plane are different, and vortex beams are generated by utilizing the interference of the unit beam optical field of the target plane. According to the invention, the phase difference between the unit beams is not required to be stably controlled to a special value, and the vortex beams can be generated on the target plane only by stably controlling the phase difference between the unit beams to be 0 or integral multiple of 2 pi by utilizing a phase control method mature in the technical field of coherent synthesis and adjusting the arrangement mode of the optical fiber laser array of the emitting surface.
Description
Technical Field
The invention relates to the technical field of fiber laser coherent synthesis, in particular to a vortex beam generation method based on a spiral line distribution phase-locked fiber laser array.
Background
The coherent synthesis of fiber laser is one of the important ways to obtain laser with high average power and high beam quality, has wide application prospects in the fields of industrial processing, free space optical communication, large scientific devices and the like, and has received wide attention of researchers at home and abroad. In recent years, many important research advances have been made in the field of coherent combining of fiber lasers. At present, the synthesis power of the coherent synthesis of the fiber laser breaks through 10 kilowatt magnitude, the number of the synthesized unit beams breaks through 100 paths, and the related work is to control the phase difference of each path of beams to be 0 or integral multiple of 2 pi by implementing phase control on the unit beams, so that the light field of the array beams is interfered on a target plane, and the energy-concentrated light spot distribution is obtained. With the development of the fiber laser coherent synthesis technology, the fiber laser coherent synthesis technology is utilized to generate a structured light field with amplitude, phase, polarization state and coherence degree having special spatial distribution, which gradually gets the attention of researchers, especially to generate a vortex light beam with spiral phase distribution and carrying orbital angular momentum.
The generation of vortex beams by coherent synthesis of fiber lasers has great potential in power boost. At present, the optical fiber laser array is mainly realized by circular arrangement or regular hexagon arrangement. Different from the situation of generating energy concentration light spot distribution, the fiber laser array system stably controls the phase difference between unit beams to be a special value through a phase control technology, so that a spiral wave front structure is fitted on an emitting surface, and vortex beams with spiral phase distribution can be generated on a target plane. However, this method requires controlling the phase difference between unit beams to a specific value and at the same time compensating for dynamic phase noise in the system, which puts higher demands on the phase control of the fiber laser array. In the existing phase control method of fiber laser coherent combination, many methods are not suitable for application scenes of generating vortex beams.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a vortex beam generation method based on a spiral line arrangement phase-locked fiber laser array.
In order to achieve the technical purpose, the technical scheme of the invention is as follows:
the vortex beam generation method based on the spiral line arrangement phase-locked fiber laser array comprises the following steps:
compensating dynamic phase noise of the fiber laser array system in real time by using a phase control technology, and stably controlling the phase difference between the light beams of the transmitting surface unit to be integral multiples of 0 or 2 pi; and the unit beams of the emitting surface in the optical fiber laser array system are arranged in a spiral line type, so that the optical paths of the unit beams at different spatial positions of the emitting surface transmitted to the same spatial position of the target plane are different, and vortex beams are generated by utilizing the interference of the unit beam optical field of the target plane.
The optical fiber laser array system comprises a seed laser, a preamplifier, a beam splitter, an optical fiber amplifier, a phase modulator array, a collimator array, a high reflector and a closed loop phase control unit, wherein collimators in the collimator array are arranged in a spiral line.
Furthermore, the number of collimators in the collimator array is N ═ m | N, the N collimators are distributed in a spiral line shape to form a spiral line arrangement collimator array, the collimators with the same number are distributed on each circle of spiral line in the spiral line arrangement collimator array, the collimators on each circle of spiral line form a spiral line arrangement subarray, and the light beam output by the collimator on each circle of spiral line is one spiral line arrangement light beam subarray in the fiber laser array output by the spiral line arrangement collimator array.
In the invention, after the output laser of the seed laser is preliminarily amplified by a preamplifier, the output laser is divided into a plurality of paths of laser by a beam splitter, each path of laser realizes power boost by an optical fiber amplifier, then the phase of each path of laser is adjusted by a phase modulator array, and each path of laser output by the phase modulator array is emitted to a free space and transmitted by a spiral line arrangement collimator array positioned on an emitting surface; the fiber laser array output by the collimator array arranged in a spiral line is transmitted to a high-reflection mirror, and the high-power reflected partial light beam is transmitted to a target plane which is away from an emission surface by a certain distance to form a vortex light beam as the output of a system; the low-power transmission part light beam is used as the input of a closed-loop phase control unit, the closed-loop phase control unit generates phase control quantity of each path of laser, and corresponding control voltage is applied to a phase modulator array according to the phase control quantity, so that the dynamic phase noise of the fiber laser array system is compensated in real time, and the phase difference between the light beams of the emission surface unit is stably controlled to be integral multiple of 0 or 2 pi.
Furthermore, the closed-loop phase control unit comprises a light field processing module, a light field information detection module and a phase control system, wherein a transmission part of light beams are focused to the light field information detection module after passing through the light field processing module, the light field information detection module converts collected light field intensity signals into electric signals and transmits the electric signals to the phase control system, and the phase control system obtains phase control quantity of each path of laser by using a phase control algorithm according to the electric signals received from the light field information detection module.
Furthermore, the light field processing module of the present invention may be formed by a lens group including a plurality of focusing lenses, and has functions of beam shrinking and focusing.
Furthermore, the light field information detection module can be composed of a photoelectric detector or a high-speed camera with a small hole, and is used for converting the acquired light field intensity signal into an electric signal and transmitting the electric signal to the phase control system.
Further, the present invention adjusts the fiber laserThe number of unit beams in the light array and the structural parameters of the spiral line arrangement collimator array positioned on the emitting surface can realize the customization of the topological charge number of the generated vortex beams. The structural parameters of the spiral line arrangement collimator array determine the space position and the topological charge number of the generated vortex light beams. Assuming that a vortex beam with a topological charge number of m needs to be generated on a target plane which is away from an emitting surface by z, the number of unit beams in the fiber laser array output by the spiral line arrangement collimator array is N ═ m | N, the fiber laser array comprises | m | beam sub-arrays arranged according to the spiral line, each beam sub-array is composed of N unit beams, and the position coordinate (x) of the q-th unit beam of the p-th beam sub-array is the position coordinate (x)pq,ypq) Comprises the following steps:
wherein, p is the serial number of light beam subarray, q is the serial number from inside to outside unit light beam in each light beam subarray, lambda is the wavelength, r is the structural parameter of helix arrangement collimator array, the interval between collimator array origin is arranged from inside to outside first collimator in helix arrangement collimator array promptly and helix, because the position coordinate of each unit light beam corresponds the position coordinate of collimator in the helix arrangement collimator array, consequently r also is the interval between the first unit light beam from inside to outside and the fiber laser array origin in the fiber laser array that the helix arranged.
The optical field distribution of the emitting surface of the fiber laser array is as follows:
wherein, w0Is the beam waist radius of the unit beam, d is the aperture of the unit beam, A0For the amplitude of the unit beam, circ (·) is a circular domain function.
The invention can achieve the following technical effects:
1. by designing the structure of the collimator array with the spiral arrangement of the emitting surface, vortex beams can be generated on a target plane when the system works in a closed-loop state.
2. By adjusting the number of the unit beams and the structural parameters of the emitting surface collimator array, the customization of the topological charge number of the generated vortex beams can be realized.
3. Compared with the existing method for generating vortex beams based on the fiber laser array, the method does not need to stably control the phase difference among the unit beams to a special value, only needs to stably control the phase difference among the unit beams to be integral multiples of 0 or 2 pi by utilizing a phase control method mature in the technical field of coherent synthesis, and can generate the vortex beams on a target plane by adjusting the arrangement mode of the fiber laser array of the emitting surface.
4. The phase control system in the invention is compatible with the phase control system of the traditional fiber laser coherent synthesis (used for realizing high-brightness laser output).
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
FIG. 1 is a schematic structural diagram of an embodiment;
FIG. 2 is a schematic structural diagram of a spiral-arrangement fiber laser array output by a spiral-arrangement collimator array;
fig. 3 is a diagram of a light intensity distribution of an emission surface fiber laser array and a light field distribution diagram of a target plane, where fig. 3(a) is a diagram of a light intensity distribution of an emission surface fiber laser array, fig. 3(b) is a diagram of a light intensity distribution of a fiber laser array transmitted to a target plane which is spaced from the emission surface by z equal to 2000m, and fig. 3(c) is a diagram of a phase distribution of a fiber laser array transmitted to a target plane which is spaced from the emission surface by z equal to 2000m in one embodiment;
fig. 4 is a diagram illustrating the effect of performing closed-loop phase control in an embodiment, where fig. 4(a) is a distribution diagram of the average light intensity of the fiber laser array beam transmitted to the light field information detection module in the presence of a phase error, fig. 4(b) is a distribution diagram of the average light intensity of the fiber laser array beam transmitted to the light field information detection module after the phase error compensation, and fig. 4(c) is a graph illustrating the convergence of the evaluation function;
fig. 5 is an average intensity distribution and a phase distribution of the target plane after phase error compensation in an embodiment, where fig. 5(a) is an average intensity distribution of the emission surface fiber laser array transmitted to the target plane at a distance z of 2000m from the emission surface, and fig. 5(b) is an average phase distribution of the emission surface fiber laser array transmitted to the target plane at a distance z of 2000m from the emission surface;
FIG. 6 is a diagram of a vortex beam with a topological charge number of 1, a light intensity distribution of an emitting surface of a fiber laser array, and a light field distribution of a target plane, where FIG. 6(a) is a diagram of a light intensity distribution of a fiber laser array of an emitting surface, FIG. 6(b) is a diagram of a light intensity distribution of a target plane when the system operates in a closed loop state, and FIG. 6(c) is a diagram of a phase distribution of a target plane when the system operates in a closed loop state, according to an embodiment;
FIG. 7 is a diagram of a vortex beam with a topological charge number of 5, a light intensity distribution of an emitting surface of a fiber laser array and a light field distribution of a target plane, FIG. 7(a) is a diagram of a light intensity distribution of a fiber laser array of an emitting surface, FIG. 7(b) is a diagram of a light intensity distribution of a target plane when the system operates in a closed loop state, and FIG. 7(c) is a diagram of a phase distribution of a target plane when the system operates in a closed loop state, according to an embodiment;
FIG. 8 is a diagram showing a vortex beam with a topological charge number of-5, a light intensity distribution of an emitting surface of a fiber laser array and a light field distribution diagram of a target plane, FIG. 8(a) is a diagram showing a light intensity distribution diagram of a fiber laser array of an emitting surface, FIG. 8(b) is a diagram showing a light intensity distribution diagram of a target plane when the system operates in a closed loop state, and FIG. 8(c) is a diagram showing a phase distribution diagram of a target plane when the system operates in a closed loop state, according to an embodiment.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Technical solutions between the embodiments of the present invention may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.
The invention provides a vortex beam generation method based on a spiral line arrangement phase-locked fiber laser array, which utilizes a phase control technology to compensate dynamic phase noise of a fiber laser array system in real time and stably controls the phase difference between light beams of an emitting surface unit to be an integral multiple of 0 or 2 pi; and the unit beams of the emitting surface in the optical fiber laser array system are arranged in a spiral line type, so that the optical paths of the unit beams at different spatial positions of the emitting surface transmitted to the same spatial position of the target plane are different, and vortex beams are generated by utilizing the interference of the unit beam optical field of the target plane.
As shown in fig. 1, an embodiment of the present invention provides a vortex beam generating system based on a spiral-arrangement phase-locked fiber laser array, including a seed laser, a preamplifier, a beam splitter, a phase modulator array, a fiber amplifier, a collimator array, a high-reflectivity mirror, and a closed-loop phase control unit. Collimator number in the collimator array is N ═ m | N, N collimators are the spiral line type and distribute and form the spiral line and arrange the collimator array, it has the collimator of the same figure to distribute on each circle spiral line in the collimator array is arranged to the spiral line, collimator on each circle spiral line constitutes a spiral line and arranges the subarray, the light beam that collimator on each circle spiral line was exported is a spiral line in the optical fiber laser array that the spiral line arranged collimator array output and arranges the light beam subarray, as shown in fig. 2, arrange the structural sketch map of optical fiber laser array for the spiral line that the collimator array was exported is arranged to the spiral line, to the vortex light beam that produces topological charge number as m, the emitting surface spiral line is arranged the collimator array and contains | m | spiral line and arranges the subarray, and contain N collimators in each spiral line arranges the subarray.
The single-frequency seed light source outputs laser which is preliminarily amplified by the preamplifier and then divided into multiple paths of laser by the beam splitter, each path of laser passes through the phase modulator array, the phase modulator array is used for adjusting the phase of each path of laser, and then power is improved by the optical fiber amplifier. And each path of laser output by the phase modulator array is transmitted to a free space through the spiral line arrangement collimator array positioned on the transmitting surface and is transmitted. The light beam array output by the collimator array arranged in the spiral line is transmitted to the high reflecting mirror, the reflecting part has higher power as the output of the system, a vortex light beam can be formed when the light beam is transmitted to a specific distance, the transmitting part is used as the input of the closed-loop control of the system, has lower power, and can provide light field information for the closed-loop control of the system. The transmission part of the light beam is focused to the light field information detection module after passing through the light field processing module. The light field processing module can be composed of a lens group containing a plurality of focusing lenses and has the functions of beam contraction and focusing. The light field information detection module can be composed of a photoelectric detector with a small hole or a high-speed camera and is used for converting collected light field intensity signals into electric signals and transmitting the electric signals to the phase control system. The phase control system obtains the phase control quantity of each path of laser by using a phase control algorithm according to the signal received from the light field information detection module, and applies control voltage to the phase modulator array, thereby realizing the real-time compensation of the dynamic phase noise of the system. The phase control algorithm is not limited, such as a random parallel gradient descent algorithm.
The customization of the topological charge number of the generated vortex light beam can be realized by adjusting the number of unit light beams in the optical fiber laser array and the structural parameters of the spiral line arrangement collimator array positioned on the emitting surface, and the spatial position and the topological charge number of the generated vortex light beam are determined by the structural parameters of the spiral line arrangement collimator array. And determining the number of unit beams and structural parameters of the collimator array arranged in the spiral line of the emitting surface according to the expected position and topological charge number of the generated vortex beams. Suppose that a topology needs to be generated in a target plane that is z away from the emission surfaceAnd (3) the number of the unit beams in the fiber laser array output by the spiral line arrangement collimator array is N ═ m | N, the number of the unit beams in the fiber laser array is | m | N, the unit beams totally comprise | m | beam sub-arrays arranged according to the spiral line, each beam sub-array is composed of N unit beams, and the position coordinate (x) of the q-th unit beam of the p-th beam sub-array is the position coordinate (x) of the q-th unit beampq,ypq) Comprises the following steps:
wherein, p is the serial number of light beam subarray, q is the serial number from inside to outside unit light beam in each light beam subarray, lambda is the wavelength, r is the structural parameter of helix arrangement collimator array, the interval between collimator array origin is arranged from inside to outside first collimator in helix arrangement collimator array promptly and helix, because the position coordinate of each unit light beam corresponds the position coordinate of collimator in the helix arrangement collimator array, consequently r also is the interval between the first unit light beam from inside to outside and the fiber laser array origin in the fiber laser array that the helix arranged.
The optical field distribution of the emitting surface of the fiber laser array is as follows:
wherein, w0Is the beam waist radius of the unit beam, d is the aperture of the unit beam, A0For the amplitude of the unit beam, circ (·) is a circular domain function.
In one embodiment of the present invention: in order to generate vortex beams with topological charge number of 2 on a target plane which is spaced from an emission surface by z equal to 2000m, a spiral line arrangement collimator array positioned on the emission surface comprises 2 sub-arrays, each sub-array comprises N equal to 35 unit beams, and the number of the unit beams in a fiber laser array output by the system is N equal to 70, wherein: beam waist radius w of unit beam0The diameter d of the unit beam is 11mm, the array structure parameter r is 60mm, and the laser working wavelength lambda is 1064 nm. In this embodiment, the emitting surfaceThe light intensity distribution of the fiber laser array is shown in fig. 3(a), and if the phase difference between the unit beams is set to 0, the light intensity distribution and the phase distribution transmitted to the target plane at a distance z of 2000m from the emission plane are obtained by numerical simulation according to the light field distribution of the emission plane by using an angular spectrum transmission method, as shown in fig. 3(b) and fig. 3 (c). The calculation result shows that under the ideal condition (no dynamic phase noise exists in the system), the vortex light beam with the expected topological charge number can be generated on the expected target plane by designing the structure of the collimator array with the spiral arrangement of the emitting surface.
However, the fiber laser array system is affected by factors such as heat and environmental disturbance, and dynamic phase noise is unavoidable, which affects the performance of generating vortex beams, so that closed-loop phase control needs to be implemented on the system, and the phase difference between unit beams is stably controlled to be an integral multiple of 0 or 2 pi. The light field processing module is composed of a focusing lens and a beam expanding system, equivalent focusing is 20m, and the phase control system loads a random parallel gradient descent algorithm to process signals input by the light field information detection module, so that phase control quantity is obtained. The random generation of 100 sets of phase errors, the average light intensity distribution of the light beams transmitted to the light field information detection module by the transmitting surface helix arrangement array light beams under the condition of the phase errors is shown in the attached figure 4(a), the random parallel gradient descent algorithm is used for compensating the 100 sets of phase errors, the average light intensity distribution of the transmitting surface helix arrangement array light beams transmitted to the light field information detection module after the phase compensation is shown in the attached figure 4(b), the normalization evaluation function convergence curve in the running process of the random parallel gradient descent algorithm is shown in the attached figure 4(c), the calculation result shows that the evaluation function can be converged for different phase errors, and the phase control system can effectively compensate the phase errors among the light beams. At this time, the light field information detection module can detect the light spot with concentrated energy.
After compensating 100 sets of phase errors by using a random parallel gradient descent algorithm, the emission surface array light beams are transmitted to the average light intensity distribution and the average phase distribution of the target plane which is 2000m away from the emission surface, as shown in fig. 5(a) and fig. 5 (b). The calculation result shows that the average light intensity distribution and the average phase distribution of the target plane are almost consistent with the calculation result under the ideal condition, the phase error in the system can be compensated through closed-loop phase control, and the vortex light beam with the expected topological charge number is generated on the expected target plane.
In addition, the spiral line arrangement phase-locking fiber laser array can also generate vortex beams with topological charge numbers of other values. Beam waist radius w of unit beam0The light intensity distribution of the emitting surface array light beam is shown in fig. 6(a), and the light intensity distribution and the phase distribution of the target plane when the system works in a closed-loop state are shown in fig. 6(b) and fig. 6 (c). The calculation result shows that the vortex light beam with the topological charge number of 1 can be generated in the target plane which is at a distance z of 2000m from the emission surface. It is expected that a vortex beam with topological charge number of 5 is generated on a target plane which is spaced from an emission surface by z equal to 2000m, the spiral arrangement collimator array of the emission surface comprises 5 sub-arrays, each sub-array comprises n equal to 35 unit beams, the light intensity distribution of the light beams of the array of the emission surface is shown in a figure 7(a), and the light intensity distribution and the phase distribution of the target plane when the system works in a closed-loop state are shown in a figure 7(b) and a figure 7 (c). The calculation results show that the vortex light beam with the topological charge number of 5 can be generated in the target plane which is at a distance z of 2000m from the emission surface. It is expected that a vortex beam with topological charge number of-5 is generated on a target plane which is spaced from an emission surface by z equal to 2000m, the collimator array in the spiral arrangement of the emission surface comprises 5 sub-arrays, each sub-array comprises n equal to 35 unit beams, the light intensity distribution of the light beams of the array of the emission surface is shown in the attached figure 8(a), and the light intensity distribution and the phase distribution of the target plane when the system works in a closed-loop state are shown in the attached figure 8(b) and the attached figure 8 (c). The calculation results show that the vortex light beam with the topological charge number of-5 can be generated in the target plane which is at a distance z of 2000m from the emission surface.
In summary, although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention.
Claims (8)
1. The vortex beam generation method based on the spiral line arrangement phase-locked fiber laser array is characterized in that dynamic phase noise of a fiber laser array system is compensated in real time by utilizing a phase control technology, and the phase difference between the light beams of the transmitting surface units is stably controlled to be 0 or integral multiple of 2 pi; and the unit beams of the emitting surface in the fiber laser array system are arranged in a spiral line shape, so that the optical paths of the unit beams of the emitting surface at different spatial positions transmitted to the same spatial position of a target plane are different, and vortex beams are generated by utilizing the interference of the light field of the unit beams of the target plane, wherein the fiber laser array system comprises a seed laser, a preamplifier, a beam splitter, a fiber amplifier, a phase modulator array, a collimator array, a high reflecting mirror and a closed loop phase control unit, all collimators in the collimator array are arranged in a spiral line shape, the number N of the collimators in the collimator array is equal to | m | N, N collimators are distributed in a spiral line shape to form a spiral line arrangement collimator array, the same number of collimators are distributed on each spiral line in the spiral line arrangement collimator array, and the collimators on each spiral line form a spiral line arrangement sub-array, the light beam output by the collimator on each circle of spiral line is a spiral line arrangement light beam subarray in the optical fiber laser array output by the spiral line arrangement collimator array.
2. The method for generating vortex beams based on the spiral-arrangement phase-locked fiber laser array according to claim 1, wherein the laser output by the seed laser is divided into multiple paths of laser through a beam splitter after being preliminarily amplified by a preamplifier, the power of each path of laser is increased through an optical fiber amplifier, then the phase of each path of laser is adjusted through a phase modulator array, and each path of laser output by the phase modulator array is transmitted to a free space through a spiral-arrangement collimator array positioned on a transmitting surface and is transmitted; the fiber laser array output by the collimator array arranged in a spiral line is transmitted to a high-reflection mirror, and the high-power reflected partial light beam is transmitted to a target plane which is away from an emission surface by a certain distance to form a vortex light beam as the output of a system; the low-power transmission part light beam is used as the input of a closed-loop phase control unit, the closed-loop phase control unit generates phase control quantity of each path of laser, and corresponding control voltage is applied to a phase modulator array according to the phase control quantity, so that the dynamic phase noise of the fiber laser array system is compensated in real time, and the phase difference between the light beams of the emission surface unit is stably controlled to be integral multiple of 0 or 2 pi.
3. The vortex beam generation method based on the spiral arrangement phase-locked fiber laser array as claimed in claim 1 or 2, wherein the closed-loop phase control unit comprises a light field processing module, a light field information detection module and a phase control system, the transmitted part of the light beam is focused on the light field information detection module after passing through the light field processing module, the light field information detection module converts the collected light field intensity signal into an electric signal and transmits the electric signal to the phase control system, and the phase control system obtains the phase control quantity of each path of laser light by using a phase control algorithm according to the electric signal received from the light field information detection module.
4. The method as claimed in claim 3, wherein the optical field processing module is configured to perform beam reduction and focusing and comprises a lens assembly including a plurality of focusing lenses.
5. The method for generating vortex beams based on the helically-arranged phase-locked fiber laser array according to claim 3, wherein the light field information detection module is formed by a photodetector with a small mounting hole or a high-speed camera.
6. The vortex beam generation method based on the spiral arrangement phase-locked fiber laser array as claimed in claim 4 or 5, wherein the customization of the topological charge number of the generated vortex beam is realized by adjusting the number of unit beams in the fiber laser array and the structural parameters of the spiral arrangement collimator array positioned on the emitting surface.
7. The method as claimed in claim 6, wherein if it is required to generate a vortex beam with a topological load m on a target plane z away from the emitting surface, the number of unit beams in the fiber laser array output by the collimator array of the spiral arrangement is N ═ m | N, and the fiber laser array includes | m | light beam sub-arrays arranged according to the spiral line, each light beam sub-array is composed of N unit beams, and the position coordinates (x) of the qth unit beam of the p light beam sub-array are the position coordinates (x) of the qth unit beam of the p light beam sub-arraypq,ypq) Comprises the following steps:
wherein p is the number of the light beam subarray, q is the number of the unit light beam from inside to outside in each light beam subarray, λ is the wavelength, and r is the structural parameter of the spiral line arrangement collimator array, that is, the distance between the first collimator from inside to outside in the spiral line arrangement collimator array and the origin of the spiral line arrangement collimator array.
8. The vortex beam generation method based on the spiral arrangement phase-locked fiber laser array as claimed in claim 7, wherein the distribution of the optical field of the emitting surface of the fiber laser array is as follows:
wherein, w0Is the beam waist radius of the unit beam, d is the aperture of the unit beam, A0For the amplitude of the unit beam, circ (·) is a circular domain function.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102944312A (en) * | 2012-11-23 | 2013-02-27 | 苏州大学 | Method for measuring partially coherent vortex light beam topological charge number |
| CN106982093A (en) * | 2017-03-31 | 2017-07-25 | 中南大学 | Free-space optical communication system and method based on many topological charge number annular beams |
| CN207587399U (en) * | 2017-12-04 | 2018-07-06 | 中国计量大学 | A kind of device that optical eddy is generated using coherent laser array |
| US10323934B1 (en) * | 2018-04-02 | 2019-06-18 | Northrop Grumman Systems Corporation | Optical protractor to measure roll angle on a static surface and rotating surface |
| CN111221132A (en) * | 2019-11-20 | 2020-06-02 | 中国科学院光电技术研究所 | Method and device for measuring vortex beam topological charge number by fan-shaped sub-aperture micro-lens array |
| CN111916985A (en) * | 2020-08-24 | 2020-11-10 | 苏州索拉科技有限公司 | Laser for generating column vector beam |
| CN111965834A (en) * | 2020-09-15 | 2020-11-20 | 北京理工大学 | Method and system for generating perfect vortex light beam array capable of being arbitrarily regulated and controlled by multiple degrees of freedom |
| CN112180591A (en) * | 2020-10-12 | 2021-01-05 | 中国人民解放军国防科技大学 | Light beam quality evaluation method based on vortex light beam generated by fiber laser array |
| CN112255782A (en) * | 2020-10-12 | 2021-01-22 | 中国人民解放军国防科技大学 | System and method for generating vortex light beams by using inclined controllable coherent fiber laser array |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105762636B (en) * | 2016-04-21 | 2019-01-22 | 上海交通大学 | A method of generating the femtosecond vortex beams of high spatial intensity contrast |
| US11067450B2 (en) * | 2018-07-06 | 2021-07-20 | University Of South Florida | Measurement apparatus of wavefront and polarization profile of vectorial optical fields |
-
2021
- 2021-01-26 CN CN202110106574.7A patent/CN112803228B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102944312A (en) * | 2012-11-23 | 2013-02-27 | 苏州大学 | Method for measuring partially coherent vortex light beam topological charge number |
| CN106982093A (en) * | 2017-03-31 | 2017-07-25 | 中南大学 | Free-space optical communication system and method based on many topological charge number annular beams |
| CN207587399U (en) * | 2017-12-04 | 2018-07-06 | 中国计量大学 | A kind of device that optical eddy is generated using coherent laser array |
| US10323934B1 (en) * | 2018-04-02 | 2019-06-18 | Northrop Grumman Systems Corporation | Optical protractor to measure roll angle on a static surface and rotating surface |
| CN111221132A (en) * | 2019-11-20 | 2020-06-02 | 中国科学院光电技术研究所 | Method and device for measuring vortex beam topological charge number by fan-shaped sub-aperture micro-lens array |
| CN111916985A (en) * | 2020-08-24 | 2020-11-10 | 苏州索拉科技有限公司 | Laser for generating column vector beam |
| CN111965834A (en) * | 2020-09-15 | 2020-11-20 | 北京理工大学 | Method and system for generating perfect vortex light beam array capable of being arbitrarily regulated and controlled by multiple degrees of freedom |
| CN112180591A (en) * | 2020-10-12 | 2021-01-05 | 中国人民解放军国防科技大学 | Light beam quality evaluation method based on vortex light beam generated by fiber laser array |
| CN112255782A (en) * | 2020-10-12 | 2021-01-22 | 中国人民解放军国防科技大学 | System and method for generating vortex light beams by using inclined controllable coherent fiber laser array |
Non-Patent Citations (3)
| Title |
|---|
| High-power vortex beam generation enabled by a phased beam array fed at the nonfocal-plane;TIANYUE HOU 等;《OPTICS EXPRESS》;20190218;全文 * |
| 相干合成涡旋光束的螺旋谱分析及应用研究;彭一鸣 等;《物理学报》;20191231;全文 * |
| 贝塞尔 -高斯涡旋光束相干合成研究;于涛 等;《物理学报》;20181231;全文 * |
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