69 results about "Birefringent crystal" patented technology

The invention discloses a method for detecting residual stress of a birefringent crystal, which is characterized by comprising the following steps of: fixing a sample to be detected on a sample loading table; the imaging lens is used for acquiring light rays which sequentially penetrate through the polarizer module, a sample to be detected on the sample loading table, the analyzer module and the camera module in four states in three states that polarization axes of the polarizer module and the analyzer module are mutually orthogonal and a polarization angle is gradually increased by 30 degrees, and in a state that the polarizer module and the analyzer module are in parallel, and the imaging lens is used for acquiring the light rays which sequentially penetrate through the polarizer module, the sample to be detected on the sample loading table, the analyzer module and the camera module in the four states; collecting a light intensity matrix set through a camera module; acquiring a reference light intensity matrix through normalized linear superposition, and performing pixel-by-pixel operation with the reference light intensity matrix on the basis of the first light intensity matrix, the second light intensity matrix and the third light intensity matrix to acquire corresponding phase delay matrixes; eliminating natural birefringence and updating a phase delay matrix by deducting respective overall average phase delay amount pixel by pixel; through pixel-by-pixel weighted stacking, isogradient lines are eliminated, and distribution information of residual stress is obtained.

The utility model relates to the technical field of laser equipment, in particular to a laser assembly, a solid-state laser and laser processing equipment, and the laser assembly comprises a birefringent crystal which is used for emitting solid-state laser under the pumping effect, and the solid-state laser comprises two pieces of orthogonal polarized light with different wavelengths; the Q switch is arranged at one end of the birefringent crystal and is used for controlling the output of the solid-state laser; and the dual-wavelength output coupler is arranged at one end, deviating from the birefringent crystal, of the Q switch and is used for coupling and outputting two orthogonal polarized lights in the solid-state laser. Through the mode, the energy loss in the laser pumping cavity can be reduced, so that the laser threshold value is reduced, and the laser output power is improved.

The present application discloses a single-frequency continuous-wave optical parametric oscillator, comprising a pumping source, a focusing lens, a resonant cavity, an optical parametric down-conversion crystal, and a birefringent crystal. The resonant cavity comprises a concave-convex lens, an output planoconcave lens, and at least two transitional planoconcave lenses; and a waist spot of pump light obtained through the focusing lens is located between the concave-convex lens and a first transitional planoconcave lens adjacent to the concave-convex lens on a light path. The center of the optical parametric down-conversion crystal coincides with a waist spot of the pump light; the birefringent crystal is located at the beam waist between the output planoconcave lens and the second transitional planoconcave lens adjacent to the output planoconcave lens on the light path; and the birefringent crystal adopts a critical phase matching or non-critical phase matching mode.

This invention relates to a nonlinear optical crystal of potassium triacetate dihydrate, its preparation method, and its uses. The molecular formula of the crystal is K3C6O8H. 10 It has a molecular weight of 331.62, belongs to the orthorhombic crystal system, and has a space group of [missing information]. P 212121, cell parameters are a =8.7596(5)Å, b =10.0487(6)Å, c =13.9979(6)Å, α =90.00° β =90.00° gamma =90.00° Z =4, V =1232.13(11)Å 3 Centimeter-sized crystals were grown using an evaporation method and an aqueous solution cooling method. Under 1064nm laser irradiation, the powder frequency doubling effect of this crystal was equivalent to that of KH₂PO₄. 4 (KDP). This crystal has an ultraviolet absorption edge shorter than 200 nm and an experimental birefringence of approximately 0.06 at 546 nm. It is simple to prepare, low in cost, exhibits significant nonlinear optical effects, a large birefringence, a wide transmission range, and is easy to grow and process. It can be used as an ultraviolet nonlinear optical crystal and a birefringent crystal.

The invention relates to a guanidino hydantoin methanesulfonate nonlinear optical crystal as well as a preparation method and application thereof. The molecular formula of the crystal is C3N3OH < 6 > (CH3SO3), the molecular weight is 195.2, the crystal belongs to an orthorhombic system, the space group is P212121, and the cell parameters are as follows: a = 5.5142 (5), b = 8.6892 (7), c = 17.4413 (16), alpha = 90.00 degrees, beta = 90.00 degrees, gamma = 90.00 degrees, Z = 4 and V = 820.5 (3) 3. Under the irradiation of 1064nm laser, the powder frequency-doubled effect of the crystal is about 3-5 times that of KH2PO4 (KDP), the ultraviolet absorption edge of the crystal is about 217nm, and the experimental birefringence is about 0.08-546nm. And growing crystals with the size of more than centimeter by adopting an evaporation method, an aqueous solution cooling method or a solvothermal method. The crystal is simple in preparation method and low in cost, has a relatively large nonlinear optical effect, a relatively large birefringence and a wide transmission range, is easy to grow and process, and can be used as an ultraviolet nonlinear optical crystal and a birefringence crystal.

Method for laser material processing using a processing laser beam (3), wherein a first laser beam (8a), which is coupled into at least a first fiber core (9a) of an optical multicore fiber (9), and a second laser beam (8b), which is coupled into at least a second fiber core (9b) of the multicore fiber (9), are generated from a polarized input laser beam (5) using a birefringent crystal (7), wherein by influencing the polarization of the input laser beam (5) the ratio in which the power of the input laser beam (5) is divided between the first and the second laser beam (8a, 8b) is changed with a modulation frequency (f) between 1 Hz and 100 kHz, in particular between 100 Hz and 100 kHz, and thereby the first and the second laser beam (8a, 8b) can be coupled out of the multi-core fiber (9) alone or together as a processing laser beam (3). characterized by that the polarization is influenced by switching between linearly, circularly or elliptically polarized polarization by means of an electro-optic polarization modulator (6), in particular a Pockels cell or Faraday rotator, which can be controlled with the modulation frequency (f) to change the polarization of the input laser beam (5).

The application discloses a single-mode fiber to multi-mode fiber mode converter which comprises a single-mode fiber head assembly, a transmitting end C lens, a birefringent crystal sequence, a receiving end C lens and a multi-mode fiber head assembly arranged coaxially; an air gap is arranged between the light emitting end of the single-mode fiber head assembly and the transmitting end C lens, and an outer envelope tube of the transmitting end collimator is coaxially fixed to the outer circumferential side of the single-mode fiber head assembly and the transmitting end C lens; the single-mode fiber to multi-mode fiber mode converter can stably assemble each optical component and ensure the overall assembly precision by means of the outer envelope tubes of the transmitting end and receiving end collimators and the inner and outer envelope tubes of the crystal group; all the components are packaged by the overall outer envelope tube, the internal optical structure is effectively protected, and the firmness of the device structure is enhanced.

An integrated electro-optical non-reciprocal mode converter based on birefringent crystal refractive index matching comprises a chip, the upper layer of the chip is an electro-optical material film with birefringent characteristics, a mode converter is prepared on the electro-optical material film, and the mode converter is a two-port device; the first port is used for receiving an input optical signal of a mode 1 and allowing the optical signal to enter the mode converter; and the second port is used for outputting the converted optical signal in the mode 2. The refractive index difference of a birefringent material to a transverse electric mode (TE) and a transverse magnetic mode (TM) is utilized to realize the pre-coarse matching of the refractive indexes of TE and TM modes, and then the fine matching of the refractive indexes and wave vectors is realized in combination with electro-optical modulation, so that the integrated electro-optical mode converter insensitive to the process is realized. The device is simple in structure and has a wide application prospect.

This invention relates to a novel birefringent crystal, its preparation and application, and belongs to the field of optical technology. The chemical formula of the birefringent crystal is Na₂ZnB₆O. 11 Na₂ZnB₆O₆ belongs to the monoclinic crystal system, space group C2 / c. This crystal can be prepared in an open system using high-temperature solid-state and high-temperature solution methods. It exhibits excellent birefringence, with a birefringence of 0.094 at 1064 nm and a transmittance of 53% at the ultraviolet cutoff edge of 190 nm. The Na₂ZnB₆O₆ prepared by the method described in this invention... 11 Birefringent crystals can be used to make polarization elements such as optical isolators, circulators, Glan prisms, and optical polarizers, and have important applications in the fields of optics and information communication.

The invention provides a reflective bidirectional light-passing magneto-optical switch, which relates to the technical field of optical communication and comprises an optical fiber collimation coupling unit, a polarization beam splitting and combining unit, a polarization state regulation and control unit, a reflection unit and a magnetic field generation and control unit which are sequentially arranged along an optical path. The 45-degree half-wave plate and the Faraday optical rotation crystal are configured to regulate and control light beam polarization, and it is ensured that optical signals are accurately guided to the output end after passing through the birefringent crystal. According to the design, the input port and the output port are integrated on the same side, compared with a transmission type structure, the magneto-optical switch has the advantages of being small in size, high in material utilization rate and compact in layout, the flexibility and adaptability of the magneto-optical switch are remarkably improved, bidirectional reversible transmission of an optical path is achieved, and the application requirement for bidirectional information interaction between channels is met.

The present application relates to the field of optical communication technology, and specifically relates to a kind of multi-channel shift circulator.It includes optical fiber unit, birefringent crystal, polarization unit, transmission or reflection unit, polarizer and reflecting element;Optical fiber unit includes at least four optical fibers, and optical signal can enter and reach birefringent crystal along any optical fiber, and birefringent crystal is used to split beam O light and E light;Transmission or reflection unit includes a plurality of PBS films, and the setting number of PBS film is same with optical fiber;Polarization unit changes the polarization state of O light and E light, so that O light and E light pass through corresponding PBS film;Enter polarizer and reflect back to polarizer by reflecting element, change the polarization state of O light and E light, so that O light and E light are reflected on corresponding PBS film to adjacent PBS film;Polarization unit can change the polarization state of reflected light, so that reflected light is combined after birefringent crystal and exits along corresponding optical fiber.Equipped with more than three ports to adapt to the application scene of the transmission of optical signal.

The utility model provides a four-channel integrated optical fiber isolator, which relates to the field of optical fiber communication and comprises a tube shell, a first optical fiber collimator and a second optical fiber collimator are respectively arranged at two ends of the tube shell, and four-core optical fibers are arranged in the first optical fiber collimator and the second optical fiber collimator. The four-core optical fibers in the first optical fiber collimator are in one-to-one correspondence with the four-core optical fibers in the second optical fiber collimator; an isolator core is arranged between the first optical fiber collimator and the second optical fiber collimator, the isolator core comprises an outer tube, a first birefringent crystal corresponding to the first optical fiber collimator and a second birefringent crystal corresponding to the second optical fiber collimator are arranged in the outer tube, and an optical rotation sheet is arranged between the first birefringent crystal and the second birefringent crystal. Compared with the prior art, the four-channel integrated optical fiber isolator has the advantages that the functions of four isolators are realized by using the boundary dimension of one conventional isolator, the use space is greatly reduced, only one isolator core and two four-core collimators are used, and the cost is saved.

The invention belongs to the technical field of birefringent crystal material preparation, and relates to a birefringent crystal and a preparation method and application thereof. The chemical formula of the birefringent crystal is (C6H7N2O) (NH2SO3), the birefringent crystal belongs to an orthorhombic crystal system, and the space group of the birefringent crystal is Pna21; the cell parameters are as follows: a is equal to 17.2986 (5); b is equal to 7.3895 (3); c is equal to 6.6272 (2); alpha = beta = gamma = 90 degrees. The birefringent crystal is in a colorless transparent sheet shape, and the ultraviolet cut-off edge is 274 nm; meanwhile, the crystal has large birefringence, and the birefringence value is 0.452 nm and 535 nm and far exceeds that of an existing commercial crystal. The preparation method comprises the following steps: taking nicotinamide and sulfamic acid as raw materials (molar ratio is 1: 1), carrying out normal-temperature liquid phase reaction, and cooling / evaporative crystallization, so that the nicotinamide derivative is prepared, the process is simple, the cost is low, and the repeatability is high.

The invention belongs to the technical field of birefringent crystal materials, and particularly relates to a birefringent crystal and a preparation method and application thereof. The chemical formula of the birefringent crystal is Na6 [ZnF2 (B12O24H6)], the birefringent crystal belongs to a trigonal system, the space group is R-3c, and the cell parameters are alpha = 90 degrees, beta = 90 degrees and gamma = 120 degrees. The crystal belongs to an indirect band gap compound, the band gap of the crystal is 4.10 eV, and the crystal has high thermal stability which can reach 380 DEG C. The birefringence of the crystal is delta n = 0.05 at 546 nm, and the crystal is a potential birefringence crystal material.

The application provides a full solid-state mode-locked laser double optical comb generating device, and relates to the technical field of optical frequency, and comprises a lens group (1), a dichroic mirror (2), a gain crystal (3), a first birefringent crystal (4), a second birefringent crystal (5) and a semiconductor saturable absorber mirror (6), wherein the pump source generates pump light which passes through the lens group (1) to converge a light spot, and passes through the dichroic mirror (2) and is connected with the gain crystal (3), the front and back sides of the gain crystal (3) are connected with the first birefringent crystal (4) and the second birefringent crystal (5) through optical connection respectively, and the second birefringent crystal (5) is connected with the semiconductor saturable absorber mirror (6); the pump light is divided into two polarized lights which are orthogonal to each other by the birefringent crystal, and the gain medium is directly pumped, so that the full solid-state mode-locked laser double optical comb with compact structure, large range of repetition frequency difference tuning and high mutual coherence is realized.

The invention relates to a fluorinated biuret borate nonlinear optical crystal and a preparation method and application thereof, the chemical formula of the crystal is [C2N3O2BF2H5] [BF4], the molecular weight is 238.71, and the crystal is prepared by a hydrothermal method or a room temperature solution method; the crystal belongs to a monoclinic system, the space group is P21, and the cell parameters are as follows: a = 6.0521 (11), b = 9.4651 (18), c = 7.1398 (12), beta = 91.267 (7), Z = 2, and V = 408.90 (13) 3. The [C2N3O2BF2H5] [BF4] nonlinear optical crystal obtained by the method is used for manufacturing a second harmonic generator, an upper frequency converter, a lower frequency converter, an optical parametric oscillator and the like; meanwhile, the crystal can also be used as a birefringent crystal for manufacturing a refractive index modulator, a phase modulator and a polarization device.

This invention provides a device and method for measuring and demonstrating the optical rotation of a substance based on a birefringent crystal conic interferogram. The device includes a measurement optical path module, an image processing module, and a support and fixing assembly. Both the measurement optical path module and the image processing module are mounted on the support and fixing assembly. The measurement optical path module, arranged sequentially along the laser propagation direction, comprises a laser emitting unit, a polarizer unit, a linked sample tube, an optical path beam expander unit, and a birefringent crystal. A frosted glass screen is located at the output end of the measurement optical path module. The image processing module is correspondingly positioned to the frosted glass screen and is used to acquire and process the interference pattern. This invention improves measurement accuracy through optical path optimization and software algorithms, and extends and improves it into a demonstration experimental linkage device, solving problems such as large errors, zero-point drift, and inability to distinguish optical rotation directions in traditional measurement methods.

The application discloses a method for realizing pulse splitting and continuous adjustment of pulse interval through a three-wedge birefringent crystal structure and relates to the optical technical field. The method is used to solve the problems of the existing pulse splitting and delay technology, such as complex system, low control precision, poor flexibility, narrow application range and the like. The technical points of the application include that a laser pulse beam is incident on a first wedge-shaped crystal, the beam is split into two beams with perpendicular polarization directions, and the two beams generate an optical path difference; a second wedge-shaped crystal is adjusted to move in one dimension along the central axis direction of the crystal, thereby adjusting the time delay; after the two beams enter the second wedge-shaped crystal in sequence, the two beams become two parallel light paths; the optical axis direction of a third wedge-shaped crystal is perpendicular to the optical axis directions of the first wedge-shaped crystal and the second wedge-shaped crystal; after the two beams pass through the third wedge-shaped crystal, the optical path difference of the two beams and the first optical path difference are offset from each other, thereby realizing the collinear transmission of the two pulses.

The utility model relates to a driving device based on an electro-optical crystal optical switch, and belongs to the technical field of optical fiber delay lines. Comprising a power supply unit, a driving control unit and an optical switch unit, the power supply unit is used for providing a stable power supply for the driving control unit and the optical switch unit, the driving control unit comprises an optical switch driving module and a control signal input end, and the control signal input end is connected with the optical switch driving module; the optical switch unit comprises an optical fiber collimator, a plurality of birefringent crystal groups, a plurality of lambda / 2 slide group components, a plurality of transparent ferroelectric ceramic groups, a plurality of beam splitting prisms, a plurality of birefringent crystal combination units, a roof prism, a double-optical fiber collimator and a photoelectric detector connected with the plurality of beam splitting prisms which are connected in sequence. The technical problems that the driving voltage of an electro-optical switch in the prior art is extremely high, and a protection structure for the characteristic is lacked are solved.

The present application relates to a compound vanadium lithium selenite and vanadium lithium selenite birefringent crystal and preparation method and use, the chemical formula of the compound is LiV3Se2O 12 , the molecular weight is 509.68, is made by vacuum packaging method, the chemical formula of the crystal is LiV3Se2O 12 , the crystal belongs to triclinic system, and space group cell parameters are α=91.80 (4) °, β=93.15 (4) °, γ=106.24 (4) °. Z=2.At wavelength 546nm its birefringence Δn=0.5, the light transmission band 0.5 μm to 7 μm.Prepared by chemical vapor deposition method, high temperature melt method or crucible descending method, the size of LiV3Se2O 12 Birefringent crystal obtained by the method is centimeter level, moderate mechanical hardness, easy to cut, polish, process and preserve, insoluble in water, not deliquescent, stable in air;It is suitable for making optical communication components or polarizing prism of various purposes, and these devices utilize the refractive index characteristics of the crystal, especially the larger birefringence.

The invention relates to a multi-point optical measuring device (1) comprising a source (2) for emitting laser pulses, at least two beam splitting modules (4) intended to be traversed by said pulses and to split an incident laser beam (7) into a plurality of parallel beams (8), at least one converging lens (5) arranged between the source (2) and the beam splitting modules (4), a measuring region (6), and beam splitting modules (4) intended to receive a medium or sample (10) to be measured and located in the focal plane (16) of said converging lens (5), each beam splitting module (4) comprising, on the one hand, a first uniaxially birefringent crystal and, on the other hand, an identical second crystal placed behind the first crystal in the pulse path, the first birefringent crystal is configured to split an incident laser beam (7) into a common secondary beam and a very secondary beam, and the second birefringent crystal is oriented relative to the first crystal such that the very secondary beam obtained from the laser beam (7) takes a common path through the second birefringent crystal, and causing the ordinary secondary beam obtained from the laser beam (7) to take a non-normal path through the second birefringent crystal, the pulses of the beam (8) output from the module (4) reaching the medium or sample (10) to be measured simultaneously and at a plurality of points (9).

A dual frequency laser for a dual mode optical lattice atomic clock is provided, which includes a 532 nm pump laser source, a beam splitter set, a dichroic mirror, a titanium sapphire crystal, a birefringent crystal, an electro-optic crystal, a concave reflector and a PZT. The dichroic mirror and the concave reflector form a first resonant cavity configured to generate a laser; the beam splitter set is configured to split a collimated pump beam into two spatially separated pump beams; an optical axis of the birefringent crystal generates propagation paths for ordinary ray and extraordinary ray within the same cavity to form two eigen modes; the electro-optic crystal is configured to add an electric field externally in a direction parallel to an electric vector of the ordinary ray or the extraordinary ray; and the PZT is combined with the electro-optic crystal to regulate two laser frequencies simultaneously.

The invention provides a compound monofluorophosphate aminoguanidine monohydrate, a monofluorophosphate aminoguanidine monohydrate birefringent crystal, a preparation method and application, the chemical formula of the compound is (CN4H7) 2PO3F. H2O, the molecular weight is 266.20, and the compound is prepared by a room temperature solution method; the chemical formula of the crystal is (CN4H7) 2PO3F. H2O, the molecular weight is 266.20, the crystal belongs to a monoclinic system, the space group is P21 / c, the cell parameters are as follows: a = 4.9572 (6), b = 20.492 (3), c = 11.0338 (16), alpha = 90 degrees, beta = 91.685 (5) degrees, gamma = 90 degrees, the unit cell volume is 1120.4 (3) 3, the ultraviolet absorption edge is 214 nm, and the birefringence is 0.116 at 546 nm. The crystal is grown by adopting a hydrothermal method or a room-temperature solution method, has good chemical stability, can be used for manufacturing polarizing prisms, phase delay devices and electro-optical modulators with various purposes, such as Glan prisms, polarization beam splitters, compensators, opto-isolator circulators, optical modulators and the like, and plays an important role in the fields of optics and communication.

The application relates to a method for constructing an ultra-low-loss via hole on a thick electrode by using time / frequency shaping laser, and belongs to the field of electrode material laser processing. The implementation method is as follows: a birefringent crystal, BBO and a high-power objective are used to shape a traditional Gaussian laser into a short-wavelength laser with a certain time delay and focal depth; a harmonic beam splitter is used to solve the safety problem caused by reflected light; a light-limiting diaphragm is used to ensure that laser with high single-pulse energy is used while the spot diameter is reduced, so that an ultra-low-loss low-tortuosity pore structure is prepared on the thick electrode, and the loss is controlled within 1%. The application can solve the safety problem caused by the reflected energy of the frequency-doubled laser, reduce the problem that the introduced pore loss of the thick electrode is too high and cannot be calendered, solve the problem of capacity and rate performance reduction of the thick electrode, and improve the power density, energy density and cycle life of the thick electrode.

This invention discloses a WDM device, which sequentially includes a three-fiber collimator, a collimating lens, a prism, a WDM film, a quarter-wave plate, and a reflector. The three-fiber collimator includes three fiber heads, a birefringent crystal, and a half-wave plate assembly connected together in sequence. The three fibers of the three fiber heads are designated as port a, port b, and port c. Optical signals are input from port a, optical signals within the reflection band of the WDM film are output from port b, and optical signals within the transmission band of the WDM film are output from port c. This invention has a simple structure and small size.

The invention discloses a tellurium dioxide crystal birefringence light filter, which comprises a plurality of stages of Lyot light filtering units, each stage of Lyot light filtering unit sequentially comprises a polaroid P1, a tellurium dioxide crystal T1, a 1 / 2 wave plate W1, a tellurium dioxide crystal T2, a 1 / 4 wave plate W2, a 1 / 2 wave plate W3 and a polaroid P2, the plurality of stages of Lyot light filtering units are arranged in a crystal holder, a rotating piece is arranged on the crystal holder, and the rotating piece is arranged on the crystal holder. The 1 / 2 wave plate W3 of each level of Lyot light filtering unit is installed on a rotating piece, the optical axis direction of the 1 / 2 wave plate W3 is changed through rotation of the rotating piece, and the birefringence light filter with the caliber larger than 50 mm is achieved through the birefringence characteristic of tellurium dioxide. According to the invention, the artificial crystal tellurium dioxide is used as the birefringent crystal, so that the problem that a large aperture cannot be obtained by the existing optical filter technology based on natural crystal Iceland spar can be solved; according to the invention, the birefringent optical filter with the caliber larger than 50 mm can be realized.

This invention relates to an aminomethylphosphonic acid aminoguanidine nonlinear optical crystal, its preparation method, and its uses. The crystal has the molecular formula (CN4OH7)(CH2NH3PO3), a molecular weight of 203.15, belongs to the orthorhombic crystal system, and has a space group of [missing information]. P 212121, cell parameters are a =6.276(2)Å, b =10.239(4)Å, c =13.868(4)Å, α =90.00° β =90.00° c =90.00° Z =4, V =891.2(5)Å 3 Centimeter-sized crystals were grown using evaporation, aqueous solution cooling, or hydrothermal methods. The ultraviolet absorption edge of these crystals is shorter than 200 nm, and the experimental birefringence is approximately 0.15 at 546 nm. This crystal preparation method is simple and low-cost, exhibiting significant nonlinear optical effects, a large birefringence, a wide transmission range, and ease of growth and processing. It can be used as an ultraviolet nonlinear optical crystal and a birefringent crystal.

The invention discloses an all-solid-state common-cavity double-optical-comb mode-locked laser without cross coupling. The all-solid-state common-cavity double-optical-comb mode-locked laser comprises a pumping source, a beam expanding and collimating system, a birefringent crystal, a dichroscope, a gain crystal, a first output coupling mirror, a second output coupling mirror, a first semiconductor saturable absorption mirror and a second semiconductor saturable absorption mirror. The birefringent crystal is added behind the pump light, the pump light can be directly divided into polarized light in two directions perpendicular to each other, the pump light can be pumped in the two beams of polarized light in the cavity so as to eliminate gain competition between the two beams, operation is easy, and the structure is compact. A confocal cavity type design is adopted, and the gain crystal is placed at the waist position of a laser beam in the cavity, so that pump light at the position can be optimally matched with a laser mode in the cavity, and the power of output laser and the light-to-light conversion efficiency are greatly improved.

This invention relates to a nonlinear optical crystal of guanidinoacetic acid chloride, its preparation method, and its uses. The crystal has the molecular formula C3N3O2H8Cl, a molecular weight of 153.57, belongs to the tetragonal crystal system, and has a space group of [missing information]. I 2 d The unit cell parameters are a =15.7150(13)Å, b =15.7150(13)Å, c =11.0742(15)Å, α =90.00° β =90.00° gamma =90.00° Z =16, V =2734.9(6)Å 3 Centimeter-sized crystals were grown using evaporation, aqueous solution cooling, or hydrothermal methods. Under 1064 nm laser irradiation, the crystal exhibited a frequency doubling response similar to that of potassium dihydrogen phosphate. The ultraviolet absorption edge of the crystal was approximately 250 nm, and the experimental birefringence was approximately 0.08 at 546 nm. This crystal preparation method is simple and low-cost, possesses significant nonlinear optical effects, a large birefringence, a wide transmission range, and is easy to grow and process. It can be used as an ultraviolet nonlinear optical crystal and a birefringent crystal.

A system and method for improving the output power of mid-infrared laser generated by intra-pulse difference frequency (IPF) belongs to the field of ultrafast optics technology. The system of this invention includes a seed source, a first pulse amplification module, a spectral broadening module, a second pulse amplification module, a synchronization control module, and an IPF module. The first pulse amplification module includes, in sequence, a first isolator, a first semiconductor laser, a first wavelength division multiplexer, a first gain fiber, a second wavelength division multiplexer, and a second semiconductor laser. The second pulse amplification module includes, in sequence, a second isolator, a third semiconductor laser, a third wavelength division multiplexer, a second gain fiber, and a fiber collimator. This invention utilizes a laser amplifier to directly amplify the wavelength component required for the IPF after spectral broadening, and uses a birefringent crystal to precisely control the time delay of the pump light and signal light, thereby improving the power of the IPF mid-infrared laser. This invention also has advantages such as high conversion efficiency, simple optical path structure, and stable and reliable system.