Multi-wavelength laser frequency doubling device and multi-wavelength space laser modulation device

Abstract

The invention belongs to the technical field of laser application, and discloses a multi-wavelength laser frequency doubling device and a multi-wavelength space laser modulation device.The multi-wavelength laser frequency doubling device comprises a base A and one or more laser frequency doubling units; two rows of first mounting grooves which are parallel in the length direction of the base A are formed in the two sides of the base A, each row of first mounting grooves comprises more than two clamping grooves A which are coaxially formed, and the clamping grooves A in the two rows of first mounting grooves are symmetrically formed; the laser frequency doubling unit is mounted in clamping grooves A symmetrically formed in the two rows of first mounting grooves; each laser frequency doubling unit corresponds to the laser of one wavelength, and frequency doubling processing is carried out on the laser of the corresponding wavelength. The multi-wavelength space laser modulation device comprises a fundamental frequency laser, a selective frequency doubling mechanism provided with a multi-wavelength laser frequency doubling device, and a laser shaping and amplifying mechanism. The device has the advantages of being simple in structure and high in expansibility, is suitable for being used in a space laser application system, and conducts synchronous modulation on the multi-wavelength laser frequency, waveform and power.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser applications, relates to laser modulation technology, and particularly relates to a multi-wavelength laser frequency doubling device and a multi-wavelength spatial laser modulation device. Background Art

[0002] Multi-wavelength laser refers to the simultaneous generation or combination of multiple laser outputs with different wavelengths, which breaks through the traditional single-wavelength limitation. Multi-wavelength lasers have advantages such as a wide wavelength adjustment range, enhanced optical power output, reduced system complexity, improved working efficiency and cost-benefit, and strong adaptability; and have been continuously expanded and applied in multiple application fields. In the communication field, multi-wavelength lasers can support more channels and provide a larger data transmission capacity; in the environmental monitoring field, multi-wavelength lasers can perform more accurate pollutant detection; in the fields of materials science and life science, multi-wavelength lasers can perform multi-dimensional analysis, helping to reveal more complex physical and chemical phenomena, and so on. Therefore, multi-wavelength lasers will be one of the important directions for the future development of laser technology.

[0003] Laser frequency doubling is one of the key technologies for multi-wavelength laser modulation. In the fields of traditional solid and gas lasers, laser frequency doubling often can only be carried out for single-wavelength lasers, and it is usually difficult to perform the above processing on multi-wavelength lasers through the same system. The usual method is to perform frequency doubling, amplification, and shaping on a single-wavelength laser, and then perform beam combining of the single-wavelength laser beams. The disadvantage of this is that each single-wavelength laser itself has an independent optical path structure, plus the subsequent multi-source laser beam combining optical path structure, resulting in a relatively complex and large optical path structure for the final multi-wavelength laser, a large number of components, and a high cost, which is not conducive to subsequent system applications.

[0004] In addition, laser shaping and gain amplification are also key technologies for realizing multi-wavelength laser adjustment. Similarly, similar to the existing laser frequency doubling technology, current laser shaping and gain amplification are mainly for single-wavelength lasers. There is currently no multi-wavelength laser modulation technology that simultaneously performs frequency doubling, shaping, and amplification on multi-wavelength lasers.

[0005] The patent application document with the application number CN202411226366.0 discloses a multi-wavelength output laser and its implementation method. A fundamental frequency laser is used to output fundamental frequency laser with a fundamental frequency wavelength. Through the combination of a second wavelength module and a third module, the output of multiple wavelengths is achieved. A lens is used to modulate the divergence angles of the lasers with the second and third wavelengths, so that the directivities and divergence angles of the lasers with different wavelengths are the same, thereby ensuring that the positions where the light with different wavelengths enter the light guide arm and act on the application terminal are the same and the focusing performances are the same. It can be seen from this that in this implementation scheme, the corresponding number of implementation modules needs to be set according to the number requirement of the output laser wavelengths, such as a fundamental frequency laser, a second wavelength module, and a third wavelength module. It can be predicted that when facing the output of more than three wavelengths of laser, its implementation structure will be quite complex and difficult to meet the application requirements. Summary of the Invention

[0006] The purpose of the present invention aims at the deficiencies in the above-mentioned prior art, and provides a multi-wavelength laser frequency doubling device, which is designed into a multi-layer frequency doubling structure for the first time, and can simultaneously realize the frequency doubling processing of multiple wavelengths of laser, and improve problems such as redundant design and limited application of traditional laser frequency doubling methods.

[0007] Another purpose of the present invention aims to provide a multi-wavelength spatial laser adjustment device. Based on the designed multi-wavelength laser frequency doubling device, a multi-wavelength shaping device and a multi-wavelength gain device are further integrated to achieve the effects of simultaneous frequency doubling, shaping, and amplification of multi-wavelength laser, and improve problems such as redundant multi-wavelength laser modulation structure and limited application in traditional laser applications.

[0008] In order to achieve the above purpose, the present invention adopts the following technical solutions to implement.

[0009] The present invention provides a multi-wavelength laser frequency doubling device, which includes a base A and more than one laser frequency doubling unit; on both sides of the base A, there are two rows of first mounting grooves parallel to the length direction of the base A. Each row of first mounting grooves contains more than two coaxially arranged card slots A, and the card slots A on the two rows of first mounting grooves are symmetrically arranged; the laser frequency doubling units are installed in the symmetrically arranged card slots A of the two rows of first mounting grooves; each laser frequency doubling unit corresponds to a laser with a certain wavelength and is used to perform frequency doubling processing on the laser with the corresponding wavelength.

[0010] Laser frequency doubling is a non-linear optical process. Through this process, the frequency of the laser can be doubled, so that the wavelength is halved. When the fundamental frequency laser with a frequency of ω passes through the non-linear crystals BBO, LBO or CLBO, second harmonic generation (SHG) will occur, generating a laser with a frequency of 2ω, that is, the frequency doubled laser. For example:

[0011] (1)The 1064 nm laser output by the Nd:YAG laser can obtain a 532 nm laser after passing through the KTP crystal. Sometimes, it can also be further processed by the LBO crystal or the CLBO crystal for third-harmonic or fourth-harmonic generation to produce ultraviolet light of 355 nm or 266 nm.

[0012] (2)The potassium (K) laser of 770 nm, rubidium (Rb) laser of 795 nm, and cesium (Cs) laser of 895 nm output by the Ti:Sapphire tunable laser can obtain their second-harmonic generation lasers of 385 nm, 398 nm, and 448 nm after passing through the BBO crystal (β-barium borate) or LBO crystal (lithium triborate) with different crystal orientations.

[0013] In an implementable manner, for multi-wavelength lasers, the effective second-harmonic generation of lasers with different wavelengths and powers requires different thicknesses of the laser second-harmonic generation units. If the thickness is too small, the second-harmonic generation is insufficient; if the thickness is too large, the laser power attenuation is too large. To satisfy the effective second-harmonic generation of different-wavelength lasers and effectively control the influence of the laser power attenuation of different wavelengths, through comprehensive calculation, the width dimensions of all laser second-harmonic generation units perpendicular to the length direction of the base A are the same, and the height dimensions are the same, and the range is: width 3 - 4 cm, height 1 - 2 cm, and the length along the length direction of the base A is 1.5 - 3.5 cm. Each laser second-harmonic generation unit can transmit lasers with a wavelength range of 280 nm - 2 μm. However, each laser second-harmonic generation unit only performs second-harmonic generation on a laser of one wavelength. For lasers of non-corresponding second-harmonic generation wavelengths, in addition to having a certain power loss, no frequency conversion, wavelength transformation, or gain amplification occurs. The laser second-harmonic generation unit can be a second-harmonic generation crystal block or a transparent sealed cell filled with a second-harmonic generation medium. The second-harmonic generation medium can be a coumarin series dye.

[0014] In an implementable manner, the first installation groove provided by the present invention includes 10 card slots A, which can fix 1 - 10 laser second-harmonic generation units.

[0015] The first installation groove and the base A can be fixedly connected or slidably connected; when it is a slidable connection, the installation of laser second-harmonic generation units with different lengths can be realized, so as to meet different laser second-harmonic generation requirements and expand the applicable fields of multi-wavelength laser second-harmonic generation devices.

[0016] In Embodiment (1), the first installation groove is composed of baffle plates A installed at both ends of the base A perpendicular to the length direction of the base A and one or more partition plates A located between the two baffle plates A. A clamping groove A is formed between adjacent baffle plates A and partition plates A, or between adjacent two partition plates A; and the designs of the baffle plates A and the partition plates A are such that the air layer between them and the laser frequency doubling unit is minimized as much as possible. The baffle plates A and the partition plates A are respectively fixedly connected to the base A. The heights of the baffle plates A and the partition plates A are the same or different. Further, the heights of the baffle plates A and the partition plates A are both not less than half of the height of the laser frequency doubling unit and not more than 1.5 times the height of the laser frequency doubling unit.

[0017] In Embodiment (2), the first installation groove is composed of baffle plates A' installed at both ends of the base A perpendicular to the length direction of the base A and one or more partition plates A' located between the two baffle plates A'. A clamping groove A is formed between adjacent baffle plates A' and partition plates A', or between adjacent two partition plates A'; the baffle plates A' are fixedly or slidably connected to the base A, and the partition plates A' are slidably connected to the base A. The heights by which the baffle plates A' and the partition plates A' protrude from the base A are the same or different. Further, the heights of the baffle plates A' and the partition plates A' are both not less than half of the height of the laser frequency doubling unit and not more than 1.5 times the height of the laser frequency doubling unit.

[0018] Further, L-shaped sliding grooves A are provided on both sides of the base A; scales are marked on the cantilever A above the L-shaped sliding grooves A; the partition plates A' are integrally L-shaped and are slidably installed in the L-shaped sliding grooves A; the partition plates A' include a horizontal portion a and a vertical portion a, a notch a adapted to the height of the cantilever A is provided on the vertical portion a, the height of the horizontal portion a is adapted to the height of the horizontal notch A of the L-shaped sliding groove A, and the horizontal portion a extends out from the horizontal notch A and is locked by an adjusting handle A. The partition plates A' and the L-shaped sliding grooves A form a sliding pair, and the rapid positioning of the partition plates A' can be achieved through the scales marked on the cantilever A, and the rapid locking between the partition plates A' and the L-shaped sliding grooves A can be achieved through the adjusting handle A. Moreover, the detachable connection manner composed of the base A, the partition plates A', and the adjusting handle A endows the multi-wavelength laser frequency doubling device with the advantage of being portable, and can further expand the application range of the multi-wavelength laser frequency doubling device.

[0019] Based on the above multi-wavelength laser frequency doubling device, the present invention further provides a multi-wavelength spatial laser modulation device, which includes a fundamental frequency laser, a selective frequency doubling mechanism, and more than one set of laser shaping and amplification mechanisms; when there are more than two sets of laser shaping and amplification mechanisms, the structures of all laser shaping and amplification mechanisms are the same, including a multi-wavelength laser shaping component and a multi-wavelength laser gain amplification component; the fundamental frequency laser output by the fundamental frequency laser passes through the selective frequency doubling mechanism for selective frequency conversion, and then passes through more than one set of laser shaping and amplification mechanisms for waveform shaping and power amplification. The output of the previous set of laser shaping and amplification mechanisms serves as the input of the next set of laser shaping and amplification mechanisms. The fundamental frequency laser is used to provide fundamental frequency lasers of more than one wavelength. The selective frequency doubling mechanism includes an optical beam splitter, a frequency doubling optical path and a non-frequency doubling optical path located in two output directions behind the optical beam splitter, and an optical coupler A for coupling the lasers generated by the frequency doubling optical path and the non-frequency doubling optical path; the frequency doubling optical path includes a multi-wavelength laser frequency doubling device provided by any one of the previous implementation methods and a first multi-wavelength laser filter; the first multi-wavelength laser filter is used to filter the laser generated by the frequency doubling process of the multi-wavelength laser frequency doubling device to obtain the frequency doubled laser containing the target wavelength; the fundamental frequency laser from the fundamental frequency laser directly passes through the non-frequency doubling optical path to the optical coupler A, and is coupled with the frequency doubled laser through the optical coupler A to obtain a laser beam containing the target wavelength laser. The multi-wavelength laser shaping component includes a three-port unidirectional transmitter, a multi-wavelength laser waveform shaper, and a total reflector; the laser beam input into the multi-wavelength laser shaping component enters the multi-wavelength laser waveform shaper through the three-port unidirectional transmitter, and the target wavelength laser in the laser beam is shaped by the multi-wavelength laser waveform shaper. The shaped laser beam is reflected by the total reflector and then undergoes a second shaping by the multi-wavelength laser waveform shaper. The laser beam after the second shaping is then input into the multi-wavelength laser gain amplification component through the three-port unidirectional transmitter. The multi-wavelength laser gain amplification component includes a multi-wavelength laser gain amplification structure and a second multi-wavelength laser filter; the multi-wavelength laser gain amplification structure is used to amplify the power of the target wavelength laser input into the multi-wavelength laser gain amplification component; the second multi-wavelength laser filter is used to filter the laser beam output by the multi-wavelength laser gain amplification structure.

[0020] In one implementation method, the laser wavelength range output by the fundamental frequency laser is 280nm - 2μm. The fundamental frequency laser can be a single laser or a combination of multiple lasers; the laser output by the fundamental frequency laser is a single wavelength or multi-wavelength laser.

[0021] In one implementable manner, a selective frequency doubling mechanism is used to perform selective frequency conversion on the laser output from a fundamental frequency laser. Through an optical beam splitter, the fundamental frequency laser output from the fundamental frequency laser is divided into two paths, one path enters the frequency doubling optical path, and the other path enters the non-frequency doubling optical path. The optical beam splitter is preferably a 50:50 optical beam splitter.

[0022] Further, optical switches are respectively arranged on the frequency doubling optical path and the non-frequency doubling optical path, so that the selective frequency doubling mechanism II has a total of three switch connection modes: (1) The optical switches on the frequency doubling optical path and the non-frequency doubling optical path are simultaneously turned on; at this time, the coupled output of the selective frequency doubling mechanism is: a laser beam containing multi-wavelength target wavelength lasers composed of the fundamental frequency laser output from the fundamental frequency laser and the frequency doubled laser after being converted by a multi-wavelength laser frequency doubling device; (2) Only the optical switch in the frequency doubling optical path is turned on; at this time, the coupled output of the selective frequency doubling mechanism is: the frequency doubled laser after being converted by a multi-wavelength laser frequency doubling device; (3) Only the optical switch in the non-frequency doubling optical path is turned on; at this time, the coupled output of the selective frequency doubling mechanism is: the fundamental frequency laser output from the fundamental frequency laser.

[0023] Traditional frequency doubling optical paths often only perform frequency doubling on single-wavelength lasers. The design of the multi-wavelength laser frequency doubling device provided by the present invention can achieve multi-wavelength frequency doubling. The first mounting groove in the design of the multi-wavelength laser frequency doubling device can simultaneously carry multiple laser frequency doubling units, enabling the frequency doubling optical path to simultaneously perform frequency doubling processing on multiple wavelength lasers.

[0024] Further, a total reflection mirror for adjusting the laser transmission direction is arranged in the frequency doubling optical path or / and the non-frequency doubling optical path.

[0025] In the present invention, according to the requirements of laser waveform shaping and power amplification, the number of laser shaping and amplification mechanisms is set. When one set of laser shaping and amplification mechanisms is set, two-time Gaussian shaping of the laser waveform and one-time compensation and amplification of the laser power or energy are achieved; when N (N≥2) sets of laser shaping and amplification mechanisms are set, 2N-time Gaussian shaping of the laser waveform and N-time compensation and amplification of the laser power or energy are achieved.

[0026] In one implementable manner, for the multi-wavelength laser shaping component, the three-port unidirectional transmitter includes a port ①, a port ②, and a port ③; the port ① serves as the laser input end of the multi-wavelength laser shaping component, the port ② is docked with one end of the multi-wavelength laser waveform shaper, and the port ③ serves as the laser output end of the multi-wavelength laser shaping component. Further, the three-port unidirectional transmitter is a polarization beam splitter PBS or a beam splitter, and the applicable wavelength range is 280nm - 2μm.

[0027] In one realizable manner, for a multi-wavelength laser shaping component, the multi-wavelength laser waveform shaper performs Gaussian shaping on the laser with a wavelength range of 280 nm - 2 μm. The multi-wavelength laser waveform shaper can simultaneously optimize and modulate the waveforms of lasers with multiple central wavelengths, and it is a bidirectional transmission device. No matter from which end the laser is input, the waveform shaper can achieve Gaussian shaping of the laser waveform, so as to achieve the purpose of improving the input laser waveform. Laser waveform shaping mainly uses a series of methods such as introducing appropriate filtering, delay, amplitude adjustment, etc. in the circuit to change the waveform of the laser pulse signal. Typical types of laser waveform shapers include: liquid crystal spatial light modulators, acousto-optic tunable filters, laser pulse clipping shapers, fiber optic shapers, etc. The laser pulse clipping shaper is an all-solid-state laser pulse clipping system, which uses a high-speed electro-optical Q-switch, and the rise time and fall time are as fast as 3 ns, which is very suitable for laser pulse waveform shaping, laser pulse chopping, laser pulse clipping, regenerative amplifier switching, mode-locked pulse gating, cavity dumping, and Q-switch applications. The laser pulse clipping shaper has the advantages of reliability, lowest radiation noise, solid state, high-voltage switching, etc., and is suitable for intracavity and extracavity applications. The typical parameters of the laser pulse clipping shaper specifications are: (1) 250 nm - 2200 nm (DKDP Pockels cell is suitable for 300 - 1320 nm, BBO Pockels cell is suitable for 250 - 1320 nm, RTP Pockels cell is suitable for 500 - 2200 nm); (2) Optical rise time, fall time: about 3 ns (10 mm aperture DKDP Pockels cell); (3) Optical pulse width: about 8 ns - 1 μs; (4) Repetition frequency: 1 Hz - 2500 Hz.

[0028] In one realizable manner, for a multi-wavelength laser shaping component, the total reflector is a total reflection mirror, whose applicable wavelength range is 280 nm - 2 μm, and the reflection efficiency is 99.9%.

[0029] In one realizable manner, the multi-wavelength laser gain amplification component compensates for and amplifies the laser power or energy output by the multi-wavelength laser shaping component.

[0030] The design of the multi-wavelength laser gain amplification structure provided by the present invention can achieve multi-wavelength laser gain amplification. In the present invention, the multi-wavelength laser gain amplification structure includes a multi-wavelength laser gain amplification device; the multi-wavelength laser gain amplification device includes a base B and more than one laser gain unit; on both sides of the base B, there are two rows of second mounting grooves parallel to the length direction of the base B, each row of second mounting grooves includes more than two coaxially arranged clamping grooves B, and the clamping grooves B on the two rows of second mounting grooves are symmetrically arranged; the laser gain units are installed in the symmetrically arranged clamping grooves B of the two rows of second mounting grooves; each laser gain unit is used to amplify the power of the laser within a specified wavelength range.

[0031] Laser gain amplification is mainly based on the stimulated emission process, and the amplification of optical signals is achieved by exciting atoms or molecules in the gain medium. The gain medium (such as solid, liquid or gas) can transition to a higher energy level under the excitation of external light (provided by the pump source); when the incident laser interacts with these excited atoms or molecules, stimulated emission occurs, generating photons with the same frequency, coherent phase and direction as the input laser, thereby achieving the amplification of optical signals.

[0032] Based on the above analysis, the multi-wavelength laser gain amplification structure is also configured with a pump source adapted to the target wavelength and the same number of optical couplers B as the number of pump sources; the lasers emitted by each pump source enter the multi-wavelength laser gain amplification device together with the laser incident on the multi-wavelength laser gain amplification structure through the corresponding optical coupler B for gain amplification, and then are output through an optical collimator as a laser beam containing the laser of the target wavelength. The present invention has no restrictions on the selection of the pump source, and a pump source with a target wavelength within the corresponding working band can be selected; for two or more target wavelength lasers with an absolute value of the wavelength spacing less than 20 nm, one pump source can be used.

[0033] For multi-wavelength lasers, the thickness required for effective gain amplification of lasers with different wavelengths is different, and the power attenuation degree of lasers with different wavelengths is different when passing through the non-laser gain unit; if the thickness of the laser gain unit is too small, the laser power amplification is insufficient, and if the thickness of the laser gain unit is too large, the power attenuation of the non-corresponding wavelength laser is too large. In order to meet the effective gain amplification of the power of lasers with different wavelengths and effectively control the attenuation effect of the power of lasers with different wavelengths, through comprehensive calculation, the width dimensions of all laser gain units perpendicular to the length direction of the base B are the same, and the height dimensions are the same, and the range is: width 3-4 cm, height 1-2 cm, and the length along the length direction of the base B is 1.5-3.5 cm. Each laser gain unit can transmit lasers with a wavelength range of 280 nm - 2 μm, but each laser gain unit only amplifies the gain of lasers within the specified wavelength range. For lasers with non-corresponding gain wavelengths, in addition to having a certain power loss, no gain amplification, frequency conversion, wavelength transformation, or waveform transformation occurs. The laser gain unit can be a gain crystal block or a transparent sealed pool filled with a gain medium. The gain medium can be a coumarin series dye.

[0034] In an implementable manner, the second mounting groove provided by the present invention includes 10 card slots B, and can fix 1-10 laser gain units.

[0035] The second mounting groove and the base B can be fixedly connected or slidably connected; when it is a slidable connection, the installation of laser gain units with different lengths can be realized, so as to meet different laser gain requirements.

[0036] In Embodiment (1), the second mounting groove is composed of baffles B installed at both ends of the base B perpendicular to the length direction of the base B and one or more partitions B located between the two baffles B. A card slot B is formed between adjacent baffles B and partitions B, or between adjacent two partitions B; and the designs of the baffles B and partitions B satisfy that the air interlayer between them and the laser gain unit is minimized as much as possible. The baffles B and partitions B are respectively fixedly connected to the base B. The heights of the baffles B and partitions B are the same or different. Further, the heights of the baffles B and partitions B are not less than half of the height of the laser gain unit and not higher than 1.5 times the height of the laser gain unit.

[0037] In Embodiment (2), the second installation groove is composed of baffles B' installed at both ends of the base B along the length direction of the vertical base B and one or more partition plates B' located between the two baffles B'. A clamping groove B is formed between adjacent baffles B' and partition plates B', or between adjacent two partition plates B'; the baffles B' are fixedly or slidably connected to the base B, and the partition plates B' are slidably connected to the base B. The heights of the baffles B' and the partition plates B' above the base B are the same or different. Further, the heights of the baffles B' and the partition plates B' are both not less than half of the height of the laser gain unit and not more than 1.5 times the height of the laser gain unit.

[0038] Further, L-shaped sliding grooves B are formed on both sides of the base B; scales are marked on the cantilever B above the L-shaped sliding grooves B; the partition plate B' is integrally L-shaped and is slidably installed in the L-shaped sliding groove B; the partition plate B' includes a horizontal portion b and a vertical portion b, a notch b adapted to the height of the cantilever B is formed in the vertical portion b, the height of the horizontal portion b is adapted to the height of the horizontal notch B of the L-shaped sliding groove B, and the horizontal portion b extends out from the horizontal notch B and is locked by an adjusting handle B. The partition plate B' and the L-shaped sliding groove B form a sliding pair, and the rapid positioning of the partition plate B' can be realized through the scales marked on the cantilever B, and the rapid locking between the partition plate B' and the L-shaped sliding groove B can be realized through the adjusting handle B. Moreover, the detachable connection mode composed of the base B, the partition plate B' and the adjusting handle B enables the multi-wavelength laser gain amplifier device to have the advantage of being portable, and can further expand the use range of the multi-wavelength laser frequency doubling device and the multi-wavelength spatial laser modulation device.

[0039] In an implementable manner, the first multi-wavelength laser filter is used to lock the central wavelength laser output by all laser frequency doubling units and filter out other stray lasers outside these central wavelengths; the second multi-wavelength laser filter is used to lock the central wavelength laser output by all laser gain units and filter out other stray lasers outside these central wavelengths.

[0040] It should be noted that: (1) The laser is always incident perpendicular to the longitudinal section of the laser frequency doubling unit and the laser gain unit; (2) In the entire optical path, the laser energy output by the previous device is less than the laser energy threshold that the adjacent next device can withstand; (3) The single wavelength or multi-wavelength mentioned refers to the central wavelength of the laser.

[0041] Compared with the prior art, the present invention has the following beneficial effects: (1) The multi-wavelength laser frequency doubling device provided by the present invention can simultaneously perform frequency doubling on multiple wavelengths of laser, providing a new idea for greatly simplifying the laser optical path structure, reducing costs, and integrating the optical system while achieving effective laser frequency doubling; it breaks through the bottleneck of separately frequency doubling a single wavelength of laser and then realizing the output of multi-wavelength frequency-doubled laser through laser beam combining in the past, making the method for obtaining multi-wavelength frequency-doubled laser more concise. (2) The multi-wavelength laser frequency doubling device provided by the present invention has a detachable structure, can adjust the selection of the laser frequency doubling unit according to requirements, is applicable to different application fields, and has wide applicability; further, the first mounting groove and the base for fixing the laser frequency doubling unit can be designed as a sliding pair to meet the requirements of laser frequency doubling units of different sizes and expand the applicable fields of the multi-wavelength laser frequency doubling device. (3) The multi-wavelength spatial laser modulation device provided by the present invention can simultaneously realize the composite functions of selective frequency up-conversion of multi-wavelength laser, waveform modulation and shaping of multi-wavelength laser, power amplification of multi-wavelength laser, and filtering of multi-wavelength laser, providing a new idea for realizing efficient modulation of multi-wavelength laser; moreover, the components used in the structure have relatively low prices. Especially for the laser primary modulation and shaping structure, compared with the previous laser modulation devices, it has fewer components and can effectively save costs. (4) The multi-wavelength spatial laser modulation device provided by the present invention solves the problem that the peak power of the output laser is limited due to the waveform distortion of the previous pulsed laser, which deviates far from the Gaussian type, by using the multi-wavelength laser shaping component; it can effectively improve the single-pulse energy of the laser and enhance the application effect of the laser. (5) The multi-wavelength spatial laser modulation device provided by the present invention can realize the simultaneous operation of multiple laser gain media, providing a new idea for the simultaneous amplification of multi-wavelength laser. (6) The multi-wavelength spatial laser modulation device provided by the present invention has a simple structure and is easy to build; moreover, the number of laser frequency doubling units and laser shaping and amplification mechanisms can be increased or decreased according to needs, and it has strong expandability and flexibility. Description of the Drawings

[0042] Figure 1 It is a schematic structural diagram of the multi-wavelength laser frequency doubling device provided in Embodiment 1 of the present invention; Figure 2 It is a side view of the multi-wavelength laser frequency doubling device provided in Embodiment 1 of the present invention; Figure 3 It is a schematic structural diagram of the multi-wavelength laser frequency doubling device provided in Embodiment 2 of the present invention; Figure 4 It is a cross-sectional view perpendicular to the length direction of the base A of the multi-wavelength laser frequency doubling device provided in Embodiment 2 of the present invention; Figure 5Top view of the assembled base A, baffle A', and partition A' in Embodiment 2 of the present invention; Figure 6 Cross-sectional view of base A perpendicular to its length direction in Embodiment 2 of the present invention; Figure 7 Structural diagram of partition A' in Embodiment 2 of the present invention; Figure 8 Structural diagram of the multi-wavelength spatial laser modulation device provided in Embodiment 3 of the present invention; Figure 9 Structural diagram of the multi-wavelength laser gain amplification in Embodiment 3 of the present invention; Figure 10 Structural diagram of the multi-wavelength laser gain amplification device in Embodiment 3 of the present invention; Figure 11 Structural diagram of the multi-wavelength spatial laser modulation device provided in Embodiment 4 of the present invention; Figure 12 Structural diagram of the multi-wavelength laser gain amplification device in Embodiment 4 of the present invention; Figure 13 Cross-sectional view of the multi-wavelength laser gain amplification device perpendicular to the length direction of base B in Embodiment 4 of the present invention; Figure 14 Top view of the assembled base B, baffle B', and partition B' in Embodiment 4 of the present invention; Figure 15 Cross-sectional view of base B perpendicular to its length direction in Embodiment 4 of the present invention; Figure 16 Structural diagram of partition B' in Embodiment 4 of the present invention; In the figure, I - fundamental frequency laser; II - selective frequency doubling mechanism; III - multi-wavelength laser shaping component; IV - multi-wavelength laser gain amplification component; 1 - multi-wavelength laser frequency doubling device; 2 - optical beam splitter; 3 - optical coupler A; 4 - first multi-wavelength laser filter; 5 - three-port unidirectional transmitter; 6 - multi-wavelength laser waveform shaper; 7 - total reflector; 8 - multi-wavelength laser gain amplification structure; 9 - second multi-wavelength laser filter; K1 - first optical switch; K2 - second optical switch; 11 - base A; 111 - L-shaped chute A; 112 - cantilever A; 113 - horizontal notch A; 12 - laser frequency doubling unit; 13 - first installation groove; 131 - baffle A; 132 - partition A; 133 - baffle A'; 134 - partition A'; 1341 - horizontal part a; 1342 - vertical part a; 1343 - notch a; 14 - adjusting handle A; 81 - Multi - wavelength laser gain amplification device; 811 - Base B; 8111 - L - shaped chute B; 8112 - Cantilever B; 8113 - Horizontal notch B; 812 - Laser gain unit; 813 - Second mounting groove; 8131 - Baffle B; 8132 - Partition B; 8133 - Baffle B'; 8134 - Partition B'; 81341 - Horizontal part b; 81342 - Vertical part b; 81343 - Notch b; 814 - Adjusting handle B; 82 - Pump source; 83 - Optical coupler B; 84 - Optical collimator. Detailed implementation mode

[0043] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other implementation manners obtained by those of ordinary skill in the art without creative efforts fall within the scope protected by the present invention.

[0044] Embodiment 1

[0045] This embodiment provides a multi - wavelength laser frequency - doubling device, as Figure 1 and Figure 2 shown, which includes a base A11 and more than one laser frequency - doubling unit 12 (3 laser frequency - doubling units 12 are shown in this embodiment).

[0046] Each laser frequency - doubling unit 12 corresponds to a laser of a certain wavelength, is used for frequency - doubling the laser of the corresponding wavelength, and can transmit lasers with a wavelength range of 280 nm - 2 μm. For example, the laser frequency - doubling unit 12 can be a frequency - doubling crystal block or a transparent sealed cell filled with a frequency - doubling medium. The frequency - doubling medium can be a coumarin series dye. The sizes of all laser frequency - doubling units are the same. In this embodiment, taking the length, width and height directions of the base A11 as the direction reference, the laser frequency - doubling unit 12 has a length of 2 cm, a width of 4 cm, and a height of 2 cm.

[0047] As Figure 1 and Figure 2As shown in the figure, two rows of first mounting grooves 13 parallel to the length direction of the base A11 are provided on both sides of the base A11. Each row of first mounting grooves 13 includes 10 coaxially arranged card slots A, and the card slots A on the two rows of first mounting grooves 13 are symmetrically arranged; the laser frequency doubling unit 12 is installed in the symmetrically arranged card slots A of the two rows of first mounting grooves 13. Specifically, the first mounting groove 13 is composed of a baffle A131 installed at both ends of the base A11 in the direction perpendicular to the length direction of the base A11 and 9 partition plates A132 located between the two baffles A131. The baffle A131 and the partition plate A132 are respectively fixedly connected to the base A11. In order to effectively support the above-mentioned laser frequency doubling unit 12, the width of the base A11 is 4 cm, the height is 2 cm, and the length is determined by the lengths of the baffle A131, the partition plate A132 and the laser frequency doubling unit 12.

[0048] A card slot A is formed between adjacent baffle A131 and partition plate A132, or between adjacent two partition plates A132, and the size of the card slot A is designed to minimize the air layer between it and the laser frequency doubling unit 12. In this embodiment, the heights of the baffle A131 and the partition plate A132 are the same as the height of the laser frequency doubling unit 12, both being 2 cm; the length of the baffle A131 is 1 cm and the width is 1 cm; the length of the partition plate A132 is 0.3 cm and the width is 1 cm.

[0049] Embodiment 2

[0050] This embodiment provides a multi-wavelength laser frequency doubling device, as Figure 3 and Figure 4 shown, which includes a base A11 and more than one laser frequency doubling unit 12 (3 laser frequency doubling units 12 are shown in this embodiment).

[0051] Each laser frequency doubling unit 12 corresponds to a laser of a certain wavelength and is used to perform frequency doubling processing on the laser of the corresponding wavelength, and can transmit lasers with a wavelength range of 280 nm - 2 μm. For example, the laser frequency doubling unit 12 can be a frequency doubling crystal block or a transparent sealed cell filled with a frequency doubling medium. The frequency doubling medium can be a coumarin series dye. The sizes of all laser frequency doubling units 12 are the same. In this embodiment, taking the length, width and height directions of the base A11 as the direction reference, the laser frequency doubling unit 12 is 2 cm long, 4 cm wide and 2 cm high.

[0052] As Figure 3 and Figure 4As shown, on both sides of the base A11, there are two rows of first mounting grooves 13 parallel to the length direction of the base A11. Each row of the first mounting grooves 13 contains 10 coaxially arranged card slots A, and the card slots A on the two rows of first mounting grooves 13 are symmetrically arranged; the laser frequency doubling unit 12 is installed in the symmetrically arranged card slots A of the two rows of first mounting grooves 13. Specifically, the first mounting groove 13 is composed of baffle plates A'133 vertically installed at both ends of the base A11 in the length direction of the base A11 and 9 partition plates A'134 located between the two baffle plates A'133. In order to effectively support the above-mentioned laser frequency doubling unit 12, the width of the base A11 is 4 cm, the height is 2 cm, and the length is determined by the lengths of the baffle plates A'133, the partition plates A'134, and the laser frequency doubling unit 12.

[0053] A card slot A is formed between an adjacent baffle plate A'133 and a partition plate A'134, or between two adjacent partition plates A'134, and the size of the card slot A is designed to minimize the air layer between it and the laser frequency doubling unit 12.

[0054] In this embodiment, the baffle plate A'133 is fixedly connected to the base A11. The height of the baffle plate A'133 is the same as that of the laser frequency doubling unit 12, both being 2 cm; the length of the baffle plate A'133 is 1 cm and the width is 1 cm.

[0055] In this embodiment, the partition plate A'134 is slidably connected to the base A11. As Figures 3 - 7 shown, L-shaped sliding grooves A111 are provided on both sides of the base A11; as Figure 6As shown in the figure, the L-shaped sliding groove A111 includes a horizontal notch A113 opened in the horizontal direction and a vertical notch A opened in the vertical direction. The height of the horizontal notch A113 is 0.7 cm, and the width of the vertical notch A is 0.5 cm. The cantilever A112 above the L-shaped sliding groove A111 has a width of 0.5 cm and a height of 0.6 cm, and is marked with scales. The partition A'134 is integrally L-shaped and is slidably installed in the L-shaped sliding groove A111. The partition A'134 includes a horizontal part a1341 and a vertical part a1342. The horizontal part a1341 has a width of 1.8 cm and a height of 0.6 cm, and the vertical part a1342 has a width of 1 cm and a height of 2.7 cm. The lengths of both the horizontal part a1341 and the vertical part a1342 are 3 mm. The vertical part a1342 is provided with a notch a1343 adapted to the height of the cantilever A112. The notch a1343 has a width of 0.5 cm and a height of 0.7 cm. The height of the horizontal part a1341 is adapted to the height of the horizontal notch A113 of the L-shaped sliding groove A111, and the horizontal part a1341 extends from the horizontal notch A113. The extended part is locked by an adjusting handle A14 and a screw. The adjusting handle A14 is provided with a threaded hole adapted to the screw. During installation, the partition A'134 can be buckled on the cantilever A112 through the L-shaped sliding groove A111. The horizontal part a1341 of the partition A'134 is placed along the long-side gap of the L-shaped sliding groove A111, and then rotated 90°, and then it can be placed on the cantilever A112. By pulling the horizontal part a1341 of the partition A'134, it can slide on the cantilever A112. After selecting a suitable position according to the scales, the adjusting handle A14 and the horizontal part a1341 are tightly fastened together by a screw, and then the partition A'134 can be fixed at the corresponding position on the cantilever A112.

[0056] Through the design of the sliding connection structure between the partition A'134 and the base A11, not only can the effective fixation of the laser frequency doubling unit 12 be realized, the air layer between the partition A'134 and the laser frequency doubling unit 12 can be minimized as much as possible, but also the fixation requirements for laser frequency doubling units 12 of different sizes can be realized.

[0057] Embodiment 3

[0058] This embodiment provides a multi-wavelength spatial laser modulation device, as Figure 8 shown, which includes a fundamental frequency laser I, a selective frequency doubling mechanism II, and a group of laser shaping and amplifying mechanisms; the laser shaping and amplifying mechanism includes a multi-wavelength laser shaping component III and a multi-wavelength laser gain amplifying component IV. The fundamental frequency laser I outputs fundamental frequency laser, which undergoes selective frequency conversion by the selective frequency doubling mechanism II, then undergoes two waveform shaping processes by the multi-wavelength laser shaping component III, and then realizes the gain amplification of the laser by the multi-wavelength laser gain amplifying component IV.

[0059] The fundamental frequency laser I is used to provide laser light of more than one wavelength. The wavelength range of the laser light output by the fundamental frequency laser is 280 nm - 2 μm. The fundamental frequency laser I can be one laser or multiple lasers. The laser light output by the fundamental frequency laser is single-wavelength or multi-wavelength laser light.

[0060] The selective frequency doubling mechanism II is used to perform selective frequency conversion on the laser light output by the fundamental frequency laser. The selective frequency doubling mechanism II includes an optical beam splitter 2, a frequency doubling optical path and a non-frequency doubling optical path located in two output directions behind the optical beam splitter 2, and an optical coupler A3 for coupling the laser light generated by the frequency doubling optical path and the non-frequency doubling optical path. The frequency doubling optical path includes a first optical switch K1, a multi-wavelength laser frequency doubling device 1, and a first multi-wavelength laser filter 4 arranged in sequence. A second optical switch K2 is arranged on the non-frequency doubling optical path.

[0061] The multi-wavelength laser frequency doubling device 1 uses the multi-wavelength laser frequency doubling device provided in Embodiment 2.

[0062] The optical beam splitter 2 uses a 50:50 optical beam splitter.

[0063] The first optical switch K1 and the second optical switch K2 are selectively turned on or off, so that the selective frequency doubling mechanism II has a total of three switch connection modes: (1) The first optical switch K1 on the frequency doubling optical path and the second optical switch K2 on the non-frequency doubling optical path are turned on simultaneously; at this time, the coupled output of the selective frequency doubling mechanism II is: a laser beam containing multi-wavelength target wavelength laser light composed of the fundamental frequency laser light output by the fundamental frequency laser I and the frequency doubling laser light converted by the multi-wavelength laser frequency doubling device 1; (2) Only the first optical switch K1 in the frequency doubling optical path is turned on; at this time, the coupled output of the selective frequency doubling mechanism II is: the frequency doubling laser light converted by the multi-wavelength laser frequency doubling device 1; (3) Only the second optical switch K2 in the non-frequency doubling optical path is turned on; at this time, the coupled output of the selective frequency doubling mechanism II is: the fundamental frequency laser light output by the fundamental frequency laser I.

[0064] The first multi-wavelength laser filter 4 is used to filter the laser beam after frequency doubling by the multi-wavelength laser frequency doubling device 1 to obtain laser light containing the target wavelength.

[0065] The fundamental frequency laser light from the fundamental frequency laser I is directly transmitted through the non-frequency doubling optical path to the optical coupler A3, and is coupled with the frequency doubling laser light filtered by the first multi-wavelength laser filter 4 through the optical coupler A3 to obtain a laser beam containing the target wavelength laser light.

[0066] To adjust the laser direction in the second harmonic generation optical path after the optical beam splitter 2, a first total reflection mirror and a second total reflection mirror are further provided in the second harmonic generation optical path in this embodiment. The first total reflection mirror is disposed in one of the outgoing directions of the optical beam splitter. The multi-wavelength laser second harmonic generation device 1 and the first multi-wavelength laser filter 4 are located in the reflection direction of the first total reflection mirror. The second total reflection mirror is located in the outgoing direction of the first multi-wavelength laser filter 4, and the laser reflected by the second total reflection mirror enters the optical coupler A3.

[0067] The multi-wavelength laser shaping component III is used to perform Gaussian shaping on the laser output by the selective second harmonic generation mechanism II. The multi-wavelength laser shaping component III includes a three-port unidirectional transmission device 5, a multi-wavelength laser waveform shaper 6, and a total reflector 7. The laser output from the selective second harmonic generation mechanism II enters the multi-wavelength laser waveform shaper 6 through the three-port unidirectional transmission device 5. The target wavelength laser is shaped by the multi-wavelength laser waveform shaper 6. The shaped laser is reflected by the total reflector 7 and then undergoes a second shaping by the multi-wavelength laser waveform shaper 6. The laser after the second shaping is then input into the multi-wavelength laser gain amplification component IV through the three-port unidirectional transmission device 5.

[0068] The three-port unidirectional transmission device 5 is a polarization beam splitter prism PBS or a beam splitter mirror, and the applicable wavelength range is 280 nm - 2 μm. The three-port unidirectional transmission device 5 includes a port ①, a port ②, and a port ③; the port ① serves as the laser input end of the multi-wavelength laser shaping component, the port ② is docked with one end of the multi-wavelength laser waveform shaper 6, and the port ③ serves as the laser output end of the multi-wavelength laser shaping component.

[0069] In this embodiment, the multi-wavelength laser waveform shaper 6 performs Gaussian shaping on the laser with a wavelength range of 280 nm - 2 μm. The multi-wavelength laser waveform shaper 6 uses a laser pulse clipping shaper. The total reflector 7 uses a total reflection mirror, and its applicable wavelength range is 280 nm - 2 μm, and the reflection efficiency is 99.9%.

[0070] The multi-wavelength laser gain amplification component IV is used to compensate and amplify the laser power or energy output by the multi-wavelength laser shaping component III. The multi-wavelength laser gain amplification component IV includes a multi-wavelength laser gain amplification structure 8 and a second multi-wavelength laser filter 9.

[0071] The multi-wavelength laser gain amplification structure 8 is used to perform gain amplification on the target wavelength laser. As Figure 9As shown, the multi-wavelength laser gain amplification structure 8 includes a multi-wavelength laser gain amplification device 81, a pump source 82 adapted to the target wavelength, an optical coupler B83 having the same number as the pump source 82, and an optical collimator 84. The laser emitted by each pump source 82 passes through the corresponding optical coupler B83 and then enters the multi-wavelength laser gain amplification device 81 together with the laser incident on the multi-wavelength laser gain amplification structure 8 for gain amplification, and then is output through the optical collimator 84 as a laser beam containing the target wavelength laser.

[0072] As Figure 10 shown, the multi-wavelength laser gain amplification device 81 includes a base B811 and more than one laser gain unit 812 (2 laser gain units 812 are shown in this embodiment).

[0073] Each laser gain unit 812 amplifies the laser within a specified wavelength range and can transmit lasers with a wavelength range of 280 nm - 2 μm. For example, the laser gain unit 812 can be a gain crystal block or a transparent sealed cell filled with a gain medium. The gain medium can be a coumarin series dye. All laser gain units have the same size. In this embodiment, taking the length, width, and height directions of the base B811 as the direction reference, the laser gain unit 812 is 3 cm long, 4 cm wide, and 2 cm high.

[0074] On both sides of the base B811, there are two rows of second mounting grooves 813 parallel to the length direction of the base B811. Each row of second mounting grooves 813 contains 10 coaxially arranged card slots B, and the card slots B on the two rows of second mounting grooves 813 are symmetrically arranged; the laser gain unit 812 is installed in the symmetrically arranged card slots B of the two rows of second mounting grooves 813. Specifically, the second mounting groove 813 is composed of a baffle B8131 vertically installed at both ends of the base B811 in the length direction of the base B811 and 9 partition plates B8132 located between the two baffles B8131. The baffle B8131 and the partition plate B8132 are fixedly connected to the base B811 respectively. In order to effectively support the above-mentioned laser gain unit 812, the width of the base B811 is 4 cm, the height is 2 cm, and the length is determined by the lengths of the baffle B8131, the partition plate B8132, and the laser gain unit 812.

[0075] A card slot B is formed between adjacent baffle B8131 and partition plate B8132, or between adjacent two partition plates B8132, and the size of the card slot B is designed to minimize the air layer between it and the laser gain unit 812 as much as possible. In this embodiment, the heights of the baffle B8131 and the partition plate B8132 are the same as the height of the laser gain unit 812, both being 2 cm; the baffle B8131 is 1 cm long and 1 cm wide; the partition plate B8132 is 0.3 cm long and 1 cm wide.

[0076] In this embodiment, there are no restrictions on the selection of the pump source 82. It is only necessary to select a pump source with a target wavelength within the corresponding working band. For two or more target wavelength lasers with an absolute value of the wavelength spacing less than 20 nm, one pump source can be used. Figure 9 An example of setting two pump sources 82 in the multi-wavelength laser gain amplification structure 8 is shown. The two pump sources 82 are configured with two optical couplers B83. The lasers emitted by the two pump sources 82 enter the multi-wavelength laser gain amplification device 81 for power amplification together with the laser incident on the multi-wavelength laser gain amplification structure 8 after passing through the corresponding optical couplers B83, and then are output as a laser beam containing the target wavelength laser through the optical collimator 84.

[0077] The second multi-wavelength laser filter 9 is used to filter the laser beam output by the multi-wavelength laser gain amplification structure 8 to obtain the final target wavelength laser.

[0078] Embodiment 4

[0079] This embodiment is a further improvement based on Embodiment 3.

[0080] The multi-wavelength spatial laser modulation device provided in this embodiment, as Figure 11 shown, includes a fundamental frequency laser I, a selective frequency doubling mechanism II, and three groups of laser shaping and amplification mechanisms. The structures of the three groups of laser shaping and amplification mechanisms are the same, and each includes a multi-wavelength laser shaping component III and a multi-wavelength laser gain amplification component IV. The fundamental frequency laser I outputs fundamental frequency laser, which undergoes selective frequency conversion by the selective frequency doubling mechanism II, and then undergoes waveform shaping and power amplification in sequence by the three groups of laser shaping and amplification mechanisms. The output of the previous group of laser shaping and amplification mechanisms serves as the input of the next group.

[0081] The structures of the fundamental frequency laser I, the selective frequency doubling mechanism II, and the multi-wavelength laser shaping component III are the same as those in Embodiment 3.

[0082] In this embodiment, as Figure 11 shown, the multi-wavelength laser gain amplification component IV includes a multi-wavelength laser gain amplification structure 8 and a second multi-wavelength laser filter 9. As Figure 9 shown, the multi-wavelength laser gain amplification structure 8 includes a multi-wavelength laser gain amplification device 81, a pump source 82 adapted to the target wavelength, an optical coupler B83 having the same number as the pump source 82, and an optical collimator 84. The lasers emitted by each pump source 82 enter the multi-wavelength laser gain amplification device 81 for power amplification together with the laser incident on the multi-wavelength laser gain amplification structure 8 after passing through the corresponding optical couplers B83, and then are output as a laser beam containing the target wavelength laser through the optical collimator 84.

[0083] As Figures 12 - 13As shown, the multi-wavelength laser gain amplification device 81 includes a base B811 and more than one laser gain unit 812 (two laser gain units 812 are shown in this embodiment).

[0084] Each laser gain unit 812 amplifies the laser within a specified wavelength range and can transmit lasers with a wavelength range of 280 nm - 2 μm. For example, the laser gain unit 812 can be a gain crystal block or a transparent sealed cell filled with a gain medium. The gain medium can be a coumarin series dye. The sizes of all laser gain units are the same. In this embodiment, taking the length, width, and height directions of the base B811 as the direction reference, the laser gain unit 812 has a length of 3 cm, a width of 4 cm, and a height of 2 cm.

[0085] As Figures 12 - 13 shown, two rows of second mounting grooves 813 parallel to the length direction of the base B811 are provided on both sides of the base B811. Each row of second mounting grooves 813 contains 10 coaxially arranged card slots B, and the card slots B on the two rows of second mounting grooves 813 are symmetrically arranged; the laser gain unit 812 is installed in the symmetrically arranged card slots B of the two rows of second mounting grooves 813. Specifically, the second mounting groove 813 is composed of baffle plates B'8133 vertically installed at both ends of the base B811 in the length direction of the base B811 and 9 partition plates B'8134 located between the two baffle plates B'8133. In order to effectively support the above-mentioned laser gain unit 812, the width of the base B811 is 4 cm, the height is 2 cm, and the length is determined by the lengths of the baffle plates B'8133, the partition plates B'8134, and the laser gain unit 812.

[0086] A card slot B is formed between adjacent baffle plates B'8133 and partition plates B'8134, or between adjacent two partition plates B'8134, and the size of the card slot B is designed to minimize the air layer between it and the laser gain unit 812.

[0087] In this embodiment, the baffle plate B'8133 is fixedly connected to the base B811. The height of the baffle plate B'8133 is the same as the height of the laser gain unit 812, both being 2 cm; the baffle plate B'8133 has a length of 1 cm and a width of 1 cm.

[0088] In this embodiment, the partition plate B'8134 is slidably connected to the base B811. As Figures 12 - 16 shown, L-shaped sliding grooves B8111 are provided on both sides of the base B811; as Figure 15As shown in the figure, the L-shaped sliding groove B8111 includes a horizontal notch B8113 opened in the horizontal direction and a vertical notch B opened in the vertical direction. The height of the horizontal notch B8113 is 0.7 cm, and the width of the vertical notch B is 0.5 cm. The cantilever B8112 above the L-shaped sliding groove B8111 has a width of 0.5 cm and a height of 0.6 cm, and is marked with scales. The partition B'8134 is integrally L-shaped and is slidably installed in the L-shaped sliding groove B8111. The partition B'8134 includes a horizontal portion b81341 and a vertical portion b81342. The horizontal portion b81341 has a width of 1.8 cm and a height of 0.6 cm, and the vertical portion b81342 has a width of 1 cm and a height of 2.7 cm. The lengths of both the horizontal portion b81341 and the vertical portion b81342 are 3 mm. The vertical portion b81342 is provided with a notch b81343 adapted to the height of the cantilever B8112. The notch b81343 has a width of 0.5 cm and a height of 0.7 cm. The height of the horizontal portion b81341 is adapted to the height of the horizontal notch B8113 of the L-shaped sliding groove B8111, and the horizontal portion b81341 extends from the horizontal notch B8113. The extended portion is locked by an adjusting handle B814 and a screw. The adjusting handle B814 is provided with a threaded hole adapted to the screw. During installation, the partition B'8134 can be buckled on the cantilever B8112 through the L-shaped sliding groove B8111. The horizontal portion b81341 of the partition B'8134 is placed along the long side gap of the L-shaped sliding groove B8111, and then rotated 90°, and then it can be placed on the cantilever B8112. By pulling the horizontal portion b81341 of the partition B'8134, it can slide on the cantilever B8112. After selecting a suitable position according to the scale, the adjusting handle B814 and the horizontal portion b81341 are tightly fastened together by a screw, and then the partition B'8134 can be fixed at the corresponding position on the cantilever B8112.

[0089] Through the design of the sliding connection structure between the partition B'8134 and the base B811, not only can the effective fixation of the laser gain unit 812 be realized, the air layer between the partition B'8134 and the laser gain unit 812 can be minimized as much as possible, but also the fixation requirements for laser gain units 812 of different sizes can be realized.

[0090] In this embodiment, there is no restriction on the selection of the pump source. Just select a pump source with the target wavelength within the corresponding working band. For two or more target wavelength lasers with the absolute value of the wavelength spacing less than 20 nm, one pump source can be used.

[0091] The second multi-wavelength laser filter 9 is used to filter the laser beam output by the multi-wavelength laser gain amplification structure 8 to obtain the final target wavelength laser.

[0092] To optimize the spatial configuration of the multi-wavelength spatial laser modulation device, in this embodiment, a third total reflection mirror for adjusting the laser direction is further disposed in the laser output direction of the second group of laser shaping and amplifying mechanisms. The laser beam reflected by the third reflection mirror enters the third group of laser shaping and amplifying mechanisms for waveform shaping and power amplification.

[0093] Application Example 1

[0094] Based on the multi-wavelength spatial laser modulation device provided in Embodiment 4, this application example realizes the modulation output of six target wavelengths.

[0095] In a specific implementation manner, the fundamental frequency laser I is a potassium-rubidium-cesium (K-Rb-Cs) three-wavelength alkali metal vapor laser. When working, the fundamental frequency laser I outputs a mixed three-wavelength laser of 770 nm (K laser), 795 nm (Rb laser), and 895 nm (Cs laser). Three BBO crystal blocks for the three wavelengths of 770 nm, 795 nm, and 895 nm are previously inserted into the first installation groove 13. When these three BBO crystal blocks are disposed in the first installation groove 13, they have different crystal orientations relative to the incident light direction to meet the frequency doubling of the above three wavelengths of laser. The first multi-wavelength laser filter 4 is used to lock the three-wavelength laser of 385 nm, 398 nm, and 448 nm. The three-port unidirectional transmitter 5 is a PBS (polarizing beam splitter prism). The multi-wavelength laser waveform shaper 6 uses a laser pulse clipping shaper. In the multi-wavelength laser gain amplifier 81, there are two types of laser gain units, namely a titanium sapphire crystal and a transparent sealed cell filled with coumarin, which respectively perform gain amplification on the six wavelengths of 770 nm, 795 nm, 895 nm, 385 nm, 398 nm, and 448 nm. Since the absolute value of the distance between 385 nm and 398 nm is less than 20 nm, the same pump source can be used. Therefore, the multi-wavelength laser gain amplification structure 8 is provided with 5 pump sources 82 adapted to each target wavelength and 5 optical couplers B83. The second multi-wavelength laser filter 9 is used to lock the laser of the six wavelengths of 770 nm, 795 nm, 895 nm, 385 nm, 398 nm, and 448 nm.

[0096] When the first optical switch K1 and the second optical switch K2 are turned on simultaneously, half of the beams of the above three-wavelength laser remain as a three-wavelength laser of 770 nm, 795 nm, and 895 nm after passing through the second optical switch K2. The other half of the beams, after passing through the first optical switch K1, are frequency-doubled by the multi-wavelength laser frequency-doubling device 1 to obtain a three-wavelength laser of 385 nm, 398 nm, and 448 nm. Then, after passing through the first multi-wavelength laser filter 4, the three-wavelength laser of 385 nm, 398 nm, and 448 nm is locked, and other stray light is filtered out and then output; the optical coupler A3 transmits the three-wavelength laser of 770 nm, 795 nm, and 895 nm, and at the same time reflects the three-wavelength laser of 385 nm, 398 nm, and 448 nm. Therefore, the two beams of light are simultaneously coupled by the optical coupler A3 to obtain a six-wavelength alkali metal laser output with wavelengths of 770 nm, 795 nm, 895 nm, 385 nm, 398 nm, and 448 nm. The laser of these six wavelengths enters from port ① of the three-port unidirectional transmitter 5 and is output from port ② of the three-port unidirectional transmitter 5; the multi-wavelength laser waveform shaper 6 and the total reflector 7 are two devices that can process the laser of these six wavelengths; the multi-wavelength laser waveform shaper 6 has laser transmission channels for these six wavelengths and can perform Gaussian shaping on the waveforms of the laser of these six wavelengths. The six-wavelength laser after waveform shaping is reflected by 99.9% by the total reflector 7 and enters the multi-wavelength laser waveform shaper 6 again in the reverse direction to perform secondary waveform shaping. At this time, the polarization characteristic of the above six-wavelength laser has changed by π / 2. Therefore, the six-wavelength laser is output from the multi-wavelength laser waveform shaper 6 and then output from port ③ of the three-port unidirectional transmitter 5, and is compensated and amplified in power by the multi-wavelength laser gain amplification structure 8.

[0097] The amplified laser is then filtered by the second multi-wavelength laser filter 9 to remove stray light, and the lasers with center wavelengths at 770 nm, 795 nm, 895 nm, 385 nm, 398 nm, and 448 nm are locked.

[0098] In the above manner, after the six-wavelength laser is subjected to waveform shaping, power amplification by the second set of laser shaping and amplification mechanisms and waveform shaping, power amplification by the third set of laser shaping and amplification mechanisms, a six-wavelength alkali metal laser output of 770 nm, 795 nm, 895 nm, 385 nm, 398 nm, and 448 nm that has undergone a total of six waveform shaping operations and three energy / power amplifications is obtained, and the deviation between its center wavelength and the target wavelength does not exceed 2 nm.

[0099] Application Example 2

[0100] This application example realizes the modulation output of dual wavelengths based on the multi-wavelength spatial laser modulation device provided in Embodiment 4.

[0101] In a specific implementation, the fundamental frequency laser I is a Nd:YAG solid laser. When it works, the fundamental frequency laser I outputs single-wavelength laser of 1064 nm. A second harmonic generation KTP crystal block for the 1064 nm wavelength is pre-inserted into the first installation groove 13. The first multi-wavelength laser filter 4 is used to lock the 532 nm wavelength laser. The three-port unidirectional transmitter 5 is a PBS (polarizing beam splitter prism). The multi-wavelength laser waveform shaper 6 uses a laser pulse clipping shaper. In the multi-wavelength laser gain amplifier 81, there are two types of laser gain units (Nd:YAG crystal and a transparent sealed dye cell filled with coumarin), which respectively amplify the lasers of 1064 nm and 532 nm wavelengths; the multi-wavelength laser gain amplification structure 8 is provided with 2 pump sources 82 adapted to each target wavelength and 2 optical couplers B83. The second multi-wavelength laser filter 9 is used to lock the lasers of 1064 nm and 532 nm wavelengths.

[0102] When the first optical switch K1 and the second optical switch K2 are turned on simultaneously, half of the 1064 nm laser beam remains 1064 nm laser after passing through the second optical switch K2, and the other half of the 1064 nm laser beam passes through the first optical switch K1, is doubled in frequency by the multi-wavelength laser frequency doubling device 1 to obtain a 532 nm wavelength laser, and then is locked by the first multi-wavelength laser filter 4 to the 532 nm wavelength laser, and after filtering out other stray light, the doubled frequency laser in the 532 nm band is output; the optical coupler A3 transmits the 1064 nm wavelength laser and reflects the 532 nm wavelength laser at the same time. Therefore, when the two beams of light are coupled by the optical coupler A3 at the same time, a dual-wavelength laser with wavelengths of 1064 nm and 532 nm will be output. The lasers of these wavelengths enter from port ① of the three-port unidirectional transmitter 5 and are output from port ② of the three-port unidirectional transmitter 5; the multi-wavelength laser waveform shaper 6 and the total reflector 7 are two devices that can process the lasers of 1064 nm and 532 nm wavelengths; the multi-wavelength laser waveform shaper 5 has transmission channels for the lasers of these two wavelengths, and can perform Gaussian shaping on the waveforms of the lasers of 1064 nm and 532 nm wavelengths. The shaped dual-wavelength laser is reflected by 99.9% by the total reflector 7, enters the multi-wavelength laser waveform shaper 6 again in the reverse direction, and performs secondary waveform shaping. At this time, the polarization characteristics of the 1064 nm and 532 nm dual-wavelength lasers have changed by π / 2. Therefore, the lasers of these two wavelengths are output from the multi-wavelength laser waveform shaper 6, then output from port ③ of the three-port unidirectional transmitter 5, and are compensated and amplified in power by the multi-wavelength laser gain amplification structure 8.

[0103] The amplified laser is then filtered by the second multi-wavelength laser filter 9 to remove stray light and lock the dual-wavelength laser with the center wavelengths at 1064 nm and 532 nm.

[0104] In the above-described manner, after the dual-wavelength laser undergoes waveform shaping and power amplification by the second group of laser shaping and amplification mechanisms, and then undergoes waveform shaping and power amplification by the third group of laser shaping and amplification mechanisms, a 1064nm and 532nm dual-wavelength laser output that has undergone a total of six waveform shapings and three energy / power amplifications is obtained, and the deviation between its central wavelength and the target wavelength does not exceed 2nm.

[0105] Those of ordinary skill in the art will realize that the embodiments described herein are for helping the reader understand the principles of the present invention, and it should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those of ordinary skill in the art can make various other specific deformations and combinations that do not depart from the essence of the present invention based on the technical revelations disclosed in the present invention, and these deformations and combinations are still within the protection scope of the present invention.

Claims

1. A multi-wavelength laser frequency doubling device, characterized in that, It includes a base A (11) and more than one laser frequency doubling unit (12); on both sides of the base A (11), there are two rows of first mounting grooves (13) parallel to the length direction of the base A (11). Each row of the first mounting grooves (13) contains more than two coaxially arranged clamping grooves A, and the clamping grooves A on the two rows of the first mounting grooves (13) are symmetrically arranged; the laser frequency doubling units (12) are installed in the symmetrically arranged clamping grooves A of the two rows of the first mounting grooves (13); each laser frequency doubling unit (12) corresponds to a laser of a certain wavelength and is used for frequency doubling processing of the laser of the corresponding wavelength.

2. The multi-wavelength laser frequency doubling device according to claim 1, wherein When the number of the laser frequency doubling units (12) is more than two, the width dimensions perpendicular to the length direction of the base A (11) of all the laser frequency doubling units (12) are the same, and the height dimensions are the same, and the range is: width 3 - 4 cm, height 1 - 2 cm, and the length along the length direction of the base A (11) is 1.5 - 3.5 cm; the laser frequency doubling unit (12) is a frequency doubling crystal block or a transparent sealed pool filled with a frequency doubling medium.

3. The multi-wavelength laser frequency doubling device according to claim 2, wherein The first mounting groove (13) is composed of baffles A (131) installed at both ends of the base A (11) perpendicular to the length direction of the base A (11) and more than one partition A (132) located between the two baffles A (131). A clamping groove A is formed between adjacent baffles A (131) and partition A (132), or between adjacent two partition A (132); the baffles A (131) and the partition A (132) are respectively fixedly connected to the base A (11); the heights of the baffles A (131) and the partition A (132) are the same or different.

4. The multi-wavelength laser frequency doubling device according to claim 2, characterized in that, The first mounting groove (13) is composed of baffles A' (133) installed at both ends of the base A (11) perpendicular to the length direction of the base A (11) and more than one partition A' (134) located between the two baffles A' (133). A clamping groove A is formed between adjacent baffles A' (133) and partition A' (134), or between adjacent two partition A' (134); the baffle A' (133) is fixedly or slidably connected to the base A (11), and the partition A' (134) is slidably connected to the base A (11); the heights of the baffles A' (133) and the partition A' (134) above the base A (11) are the same or different.

5. The multi-wavelength laser frequency doubling device according to claim 4, wherein, On both sides of the base A (11), L-shaped chutes A (111) are opened; there are scales marked on the cantilever A (112) above the L-shaped chutes A (111); the partition A' (134) is integrally L-shaped and is slidably installed in the L-shaped chutes A (111); the partition A' (134) includes a horizontal part a (1341) and a vertical part a (1342), and a notch a (1343) adapted to the height of the cantilever A (112) is opened on the vertical part a (1342). The height of the horizontal part a (1341) is adapted to the height of the horizontal notch A (113) of the L-shaped chute A (111), and the horizontal part a (1341) extends out from the horizontal notch A (113) and is locked by an adjusting handle A (14).

6. A multi-wavelength spatial laser modulation device, characterized in that, It includes a fundamental frequency laser (I), a selective frequency doubling mechanism (II), and more than one set of laser shaping and amplification mechanisms; when there are two or more sets of laser shaping and amplification mechanisms, the structures of all laser shaping and amplification mechanisms are the same, including a multi-wavelength laser shaping component (III) and a multi-wavelength laser gain amplification component (IV); the fundamental frequency laser (I) outputs fundamental frequency laser, which undergoes selective frequency conversion by the selective frequency doubling mechanism (II), and then undergoes waveform shaping and power amplification by more than one set of laser shaping and amplification mechanisms. The output of the previous set of laser shaping and amplification mechanisms serves as the input of the next set of laser shaping and amplification mechanisms. The fundamental frequency laser (I) is used to provide fundamental frequency laser of more than one wavelength. The selective frequency doubling mechanism (II) includes an optical beam splitter (2), a frequency doubling optical path and a non-frequency doubling optical path in two output directions behind the optical beam splitter (2), and an optical coupler A (3) for coupling the lasers generated by the frequency doubling optical path and the non-frequency doubling optical path; the frequency doubling optical path includes the multi-wavelength laser frequency doubling device (1) according to any one of claims 1 to 5 and a first multi-wavelength laser filter (4); the first multi-wavelength laser filter (4) is used to filter the laser generated by the frequency doubling process of the multi-wavelength laser frequency doubling device (1) to obtain frequency doubled laser containing the target wavelength; the fundamental frequency laser from the fundamental frequency laser (I) directly passes through the non-frequency doubling optical path and is transmitted to the optical coupler A (3), and is coupled with the frequency doubled laser through the optical coupler A (3) to obtain a laser beam containing the target wavelength laser. The multi-wavelength laser shaping component (III) includes a three-port unidirectional transmitter (5), a multi-wavelength laser waveform shaper (6), and a total reflector (7); the laser beam input into the multi-wavelength laser shaping component (III) enters the multi-wavelength laser waveform shaper (6) through the three-port unidirectional transmitter (5), the target wavelength laser in the laser beam is shaped by the multi-wavelength laser waveform shaper (6), the shaped laser beam is reflected by the total reflector (7) and then undergoes a second shaping by the multi-wavelength laser waveform shaper (6), and the laser beam after the second shaping is input into the multi-wavelength laser gain amplification component (IV) through the three-port unidirectional transmitter (5). The multi-wavelength laser gain amplification component (IV) includes a multi-wavelength laser gain amplification structure (8) and a second multi-wavelength laser filter (9); the multi-wavelength laser gain amplification structure (8) is used to amplify the power of the target wavelength laser input into the multi-wavelength laser gain amplification component (IV); the second multi-wavelength laser filter (9) is used to filter the laser beam output by the multi-wavelength laser gain amplification structure (8).

7. The multi-wavelength spatial laser modulation device according to claim 6, characterized in that, Optical switches are respectively arranged on the frequency doubling optical path and the non-frequency doubling optical path.

8. The multi-wavelength spatial laser modulation device according to claim 6, characterized in that, The multi-wavelength laser waveform shaper (6) performs Gaussian shaping on the laser with a wavelength range of 280 nm - 2 μm.

9. The multi-wavelength spatial laser modulation device according to claim 6, characterized in that, The multi-wavelength laser gain amplification structure (8) includes a multi-wavelength laser gain amplification device (81). The multi-wavelength laser gain amplification device (81) includes a base B (811) and more than one laser gain unit (812); on both sides of the base B (811), there are two rows of second mounting grooves (813) parallel to the length direction of the base B (811), and each row of second mounting grooves (813) includes more than two coaxially arranged clamping grooves B, and the clamping grooves B on the two rows of second mounting grooves (813) are symmetrically arranged; the laser gain unit (812) is installed in the symmetrically arranged clamping grooves B of the two rows of second mounting grooves (813); each laser gain unit (812) is used to amplify the power of the laser within a specified wavelength range.

10. The multi-wavelength spatial laser modulation device according to claim 9, characterized in that, When the number of laser gain units (812) is more than two, the widths of all laser gain units (812) perpendicular to the length direction of the base B (811) are the same, and the heights are the same, and the ranges are: width 3 - 4 cm, height 1 - 2 cm, and the length along the length direction of the base B (811) is 1.5 - 3.5 cm; the laser gain unit (812) is a gain crystal block or a transparent sealed cell filled with a gain medium.

11. The multi-wavelength spatial laser modulation device according to claim 9, wherein The multi-wavelength laser gain amplification structure (8) is also configured with a pump source (82) adapted to the target wavelength and the same number of optical couplers B (83) as the number of pump sources (82); the laser emitted by each pump source (82) enters the multi-wavelength laser gain amplification device (81) together with the laser incident on the multi-wavelength laser gain amplification structure (8) after passing through the corresponding optical coupler B (83) for gain amplification, and then is output through an optical collimator (84) to obtain a laser beam containing the laser of the target wavelength.

12. The multi-wavelength spatial laser modulation device according to claim 10, characterized in that, The second mounting groove (813) is composed of baffle plates B (8131) installed at both ends of the base B (811) perpendicular to the length direction of the base B (811) and more than one partition plate B (8132) located between the two baffle plates B (8131); a clamping groove B is formed between adjacent baffle plates B (8131) and partition plates B (8132), or between adjacent two partition plates B (8132); the baffle plates B (8131) and partition plates B (8132) are respectively fixedly connected to the base B (811); the heights of the baffle plates B (8131) and partition plates B (8132) are the same or different.

13. The multi-wavelength spatial laser modulation device according to claim 10, characterized in that, The second mounting groove (813) is composed of baffle plates B' (8133) installed at both ends of the base B (811) perpendicular to the length direction of the base B (811) and more than one partition plate B' (8134) located between the two baffle plates B' (8133); a clamping groove B is formed between adjacent baffle plates B' (8133) and partition plates B' (8134), or between adjacent two partition plates B' (8134); the baffle plates B' (8133) are fixedly or slidably connected to the base B (811), and the partition plates B' (8134) are slidably connected to the base B (811); the heights of the baffle plates B' (8133) and partition plates B' (8134) above the base B (811) are the same or different.

14. The multi-wavelength spatial laser modulation device according to claim 13, wherein, Both sides of the base B (811) are provided with L-shaped chutes B (8111); there are scales marked on the cantilever B (8112) above the L-shaped chute B (8111); the partition B' (8134) is integrally L-shaped and is slidably installed in the L-shaped chute B (8111); the partition B' (8134) includes a horizontal part b (81341) and a vertical part b (81342), a notch b (81343) adapted to the height of the cantilever B (8112) is provided on the vertical part b (81342), the height of the horizontal part b (81341) is adapted to the height of the horizontal notch B (8113) of the L-shaped chute B (8111), and the horizontal part b (81341) extends out from the horizontal notch B (8113) and is locked by an adjusting handle B (814).

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