134 results about "Phase matching" patented technology

The invention discloses a reflective array antenna control method and system based on a broadband dual-polarization unit, and the method comprises the steps: obtaining a target wave beam pointing instruction, and carrying out the orthogonal decomposition of the target wave beam pointing instruction into a first polarization control vector and a second polarization control vector; calculating a theoretical phase frequency spectrum of each unit according to the polarization control vector; calling a preset database to extract a basic phase spectrum; quantitative mapping is carried out by calculating a matching error between a theory and a basic phase frequency spectrum, a phase control code containing the first polarization and the second polarization is obtained and loaded to a corresponding broadband dual-polarization unit to drive the switching of a physical state of the broadband dual-polarization unit, and real-time reconstruction of a wave beam is realized. Compared with the prior art, the antenna can overcome the defects that a traditional reflective array antenna is serious in polarization component coupling, low in phase matching degree in a broadband range and inaccurate in phase control code acquisition, and remarkably enhances the independent pointing precision and the full-band gain stability of dual-polarization beams. Therefore, flexible reconstruction of the wave beam in polarization and frequency dimensions is realized.

The invention belongs to the technical field of nonlinear optics, and discloses a method and a structure for realizing nonlinear waveguide quasi-phase matching. A plurality of groups of micro-nano structures are formed on the nonlinear waveguide along the waveguide propagation direction, each group of micro-nano structures comprises one or more air holes, the micro-nano structures are utilized to cause relative phases between different wavelength modes to generate jump, phase differences caused by phase mismatch are compensated, and quasi-phase matching is realized. The phase matching scheme provided by the invention is applicable to all nonlinear materials and waveguides, and has the advantage of high universality.

The invention provides a high-power wide-spectrum long-wave infrared femtosecond laser generation method, and relates to the technical field of infrared ultrafast laser. According to the method, the 1.5 [mu] m pumping BGSe crystal is adopted, compared with a traditional 1 [mu] m pumping BGSe crystal, the heat accumulation effect is greatly reduced, and the operation stability of the system is remarkably improved in combination with a water-cooling heat dissipation device. Through crystal cutting angle optimization and phase matching design, 10-16 [mu] m wide-spectrum long-wave infrared femtosecond laser output is achieved, the power reaches 100 mW, and the application requirements in the fields of molecular spectrum recognition, environment monitoring and the like are met.

The invention belongs to the technical field of laser vibration measurement, and provides a self-focusing laser Doppler vibration measurement method and system capable of resisting self-vibration of an optical fiber, and the method comprises the steps: adding a compensation light path which is used for sensing and generating reference light which is equal to an interference signal in amplitude and is opposite to the interference signal in real time in a Doppler vibration measurement light path, and taking the minimum mean square error as a self-adaptive matching criterion; interference phases obtained by synchronous demodulation of the compensation light path and the main light path are subjected to adaptive matching and cancellation in amplitude and phase dimensions, residual errors of vibration of the vibration measurement system and other environmental interferences are suppressed below noise of the vibration measurement system, and the purpose of balancing and weakening optical fiber vibration interferences in an instrument is achieved. The influence of the vibration factor of the instrument is reduced, and the interference influence is accurately eliminated through amplitude and phase matching by a demodulation algorithm corresponding to a compensation light path; meanwhile, by dynamically observing and updating the return light intensity threshold, low-frequency disturbance is resisted, and accurate automatic focusing is achieved.

This invention belongs to the field of wavelength division multiplexing optical communication technology, specifically relating to a reverse coupler based on a thin-film lithium niobate platform. The reverse coupler includes: a lithium niobate-on-insulator substrate, a first waveguide, a second waveguide, and a coupling region. The first and second waveguides are disposed in the device layer of the lithium niobate-on-insulator substrate. The first and second waveguides are arranged in parallel along the light propagation direction within the coupling region. A periodic grating perturbation structure is disposed on the first and / or second waveguides. This reverse coupler utilizes the grating perturbation structure to ensure that the modes of the two waveguides satisfy the phase matching condition. The optical signal input to one waveguide is reverse-coupled to the falling port of the other waveguide. Utilizing the large photoelectric coefficient of lithium niobate material, this reverse coupler can tune its spectrum under specific conditions by applying a voltage.

The invention discloses an on-chip super-continuum spectrum light source based on a cascaded polarized ferroelectric material and a design method thereof. The pump light source is used for providing pump light; the pump light enters the super-continuum spectrum generation waveguide; the super-continuum spectrum generation waveguide meets the requirements that the group velocity dispersion is close to 0 under the wavelength of the pump light, the group velocity mismatch of the wavelength of the pump light and the wavelength of the frequency doubling light is close to 0, and the polarization period of the super-continuum spectrum generation waveguide meets the phase matching of frequency doubling. The polarization period of the super-continuum spectrum expansion waveguide changes along the propagation direction, and the super-continuum spectrum expansion waveguide outputs a super-continuum spectrum; the conical transition waveguide is used for connecting the super-continuum spectrum generation waveguide and the super-continuum spectrum expansion waveguide and eliminating mode mismatch between the super-continuum spectrum generation waveguide and the super-continuum spectrum expansion waveguide. The system has the advantages of low cost, high integration level and wide spectrum coverage, and is suitable for the fields of environmental monitoring, medical diagnosis, spectral analysis and the like.

A device and method for detecting the deuterium doping concentration of a deuterium-doped KDP crystal are disclosed. The device comprises a fundamental frequency laser, a second-harmonic deuterium-doped KDP crystal arranged sequentially along the laser output direction of the fundamental frequency laser, a frequency doubling adjuster acting on the second-harmonic deuterium-doped KDP crystal, a first second-harmonic laser color separator, a second second-harmonic laser color separator, and an energy meter. The angle at which two fundamental frequency beams of different wavelengths output from the fundamental frequency laser are incident on the second-harmonic deuterium-doped KDP crystal is controlled by the frequency doubling adjuster. Based on the reading of the energy meter, the second-harmonic deuterium-doped KDP crystal is adjusted to a position corresponding to the phase matching angle. The deuterium doping concentration of the second-harmonic deuterium-doped KDP crystal is obtained by comparing the difference in the measured phase matching angles of the two laser beams with the difference in the phase matching angle calculated according to an empirical formula and the relationship between the phase matching angle difference and the deuterium doping concentration of the crystal. This invention has the advantages of stable device and simple and accurate detection method.

The invention belongs to the technical field of nonlinear optical crystals, and particularly relates to a zeolite-like structure nitrogen oxide silicate nonlinear optical crystal and a preparation method and application thereof, the chemical general formula of the crystal is Ba3Si3N5OCl, the crystal belongs to a hexagonal system, the cell parameters of the crystal are as follows: a is 9.5147 (6), c is 5.5002 (4), V is 431.22 (6) 3, Z is 2, the space group is P-62c, and the crystal has a non-centrosymmetric structure. The Ba3Si3N5OCl crystal provided by the invention is used as a novel zeolite-like structure nitrogen oxide silicate, successfully integrates nonlinear optical activity and phase matching capability, can generate frequency doubling response which is about 0.2 times of KDP (potassium dihydrogen phosphate) under 1064 nm laser pumping, and can realize phase matching, so that the Ba3Si3N5OCl crystal becomes a nonlinear optical material with practical device application potential.

To achieve high-power single transverse mode laser, we here propose a supersymmetry (SUSY)-based triple-ridge waveguide semiconductor laser structure, which is composed of an electrically pumped main broad-ridge waveguide located in the middle and a pair of lossy auxiliary partner waveguides. The auxiliary partner waveguides are designed to provide dissipative modes that can phase match and couple with the higher-order modes in the main waveguide. By appropriately manipulating the gain-loss discrimination of the modes in the laser cavity, one can effectively suppress all the undesired higher-order transverse modes while keeping the fundamental one almost unaffected, thereby ensuring stable single-mode operation with a larger emitting aperture and accordingly a higher output power than a conventional single-transverse-mode ridge waveguide diode laser.

The present application relates to a kind of preparation methods of large aperture ultraviolet third harmonic generator, the method is first using Maker stripe method to measure the frequency doubling coefficient of guanidinium tetrafluoroborate crystal, obtain 2 non-zero effective frequency doubling coefficient;Again, the minimum deflection angle method is used to determine the principal refractive index of guanidinium tetrafluoroborate crystal from 253nm-2325nm between 11 wavelengths, fitting Sellmeier equation;According to Sellmeier equation, the computer program is calculated, and the phase matching curve of the guanidinium tetrafluoroborate crystal type I or type I is calculated, then the phase matching point of the guanidinium tetrafluoroborate crystal is determined by combining frequency doubling coefficient;Then, according to the phase matching direction, guanidinium tetrafluoroborate crystal is cut, and two light transmitting surfaces are polished and coated with dielectric film to obtain the guanidinium tetrafluoroborate crystal third harmonic generator;The large aperture ultraviolet third harmonic generator of the guanidinium tetrafluoroborate crystal is used to generate high-power third harmonic laser output, and has good practical application value in the field of laser technology, especially in high-power laser device.

An optical device (200, 300) comprising the following: a substrate (201,301); a heterogeneous metal oxide semiconductor MOS capacitor formed on the substrate, wherein the MOS capacitor comprises: an optical fiber (202, 302); a first cathode (204, 304) comprising a first material in which an optical waveguide is formed; an anode (206, 306) formed in the optical waveguide, the anode comprising a second material that differs from the first material; and a dielectric (218, 318) arranged between the first cathode and the anode, wherein the dielectric comprises an oxide of the first material and an oxide of the second material, where the heterogeneous MOS capacitor is defined between the anode and the first cathode; and a semiconductor component layer that is arranged between the substrate and the heterogeneous MOS capacitor and is formed in the optical waveguide, characterized by the fact that The semiconductor component layer and the anode form a resistance element that is integrated into the optical waveguide.

The invention provides a lateral coupling drift tube linear accelerator based on a modular drift tube structure, and the linear accelerator comprises a main acceleration cavity chain which is formed by sequentially arranging a plurality of acceleration cavities in a straight line, each acceleration cavity is internally provided with a plurality of drift tubes, and the structures and sizes of the plurality of drift tubes arranged in a single acceleration cavity are the same; the gaps among the plurality of drift tubes arranged in the single acceleration cavity are equal; the adjacent accelerating cavities are communicated through beam hole channels along the central axis of the main accelerating cavity chain; the permanent magnet type quadrupole lenses are arranged on the beam hole channels; and the side coupling cavities are formed in the off-axis positions between every two adjacent acceleration cavities, and the side coupling cavities are connected with the adjacent acceleration cavities through the coupling holes. The accelerator adopts a phase matching thought, so that the lengths of all the acceleration units in the same acceleration cavity and the structural sizes of the drift tubes are completely the same, the modular production and array installation of the drift tube structure are realized, and the manufacturing and testing work of the SCDTL is greatly simplified.

This system is directed to an orbital angular momentum generator which can include an AOD; a beam shaping optic assembly; a log-polar optic; a Fourier lens; and, wherein the orbital angular momentum generator is configured to produce pulse shaping according to the application of a quadratic waveform chirp that corresponds to one or more OAM modes. The system can include an ultrashort pulsed laser; a log-spiral transformation assembly; an AOD; an ellipse generator; a λ / 2 plate; and, wherein the optical system is configured to provide for multiple coherent spiral beams with control of amplitude and relative phase. The system can include an ultraviolet orbital angular momentum generator comprising: a femtosecond pulsed laser; a crystal configured to provide a collinear phase-matching; and can provide a UV OAM source for imaging with high resolution and quantum information. The AOD can be replaced with a scanning mirror and configured to add a linear phase gradient.

The present application relates to the field of optical communication technology, in particular to a dynamic correction method of an adaptive polarization beam combination chip applied to an optical interconnection interface, comprising the following steps: S101, acquiring the group velocities of optical signals of a first optical path and a second optical path respectively, and transmitting the optical signal with a larger group velocity to a first time delay optical path for time compensation; S102, the time delay compensated optical signal enters a first power reconstruction optical path and a second power reconstruction optical path for power adjustment; S103, the power reconstructed optical signal enters a first phase matching optical path and a second phase matching optical path for phase modulation; S104, a chip monitoring end feeds back the integrated error of the time delay, power and phase of the optical signal, and if the integrated error is greater than a set error threshold, the method returns to step S101 for re-correction. The method compensates or modulates the time delay, power ratio and phase difference, realizes high synchronization and matching of two polarization lights, and thus improves the polarization multiplexing efficiency and signal quality of the whole system.

The present invention relates to a nonlinear optical converter (11) for a laser radiation source which comprises a pump laser for generating a pump laser beam, the nonlinear optical converter comprising: a first optical parametric oscillator (OPO) crystal (2) which faces the pump laser and which is designed to generate, from the pump laser beam (6), a first pair of gain bands, in particular a signal band and an idler band, as well as residual pump radiation, and which has a first phase-matching angle (7); and a second optical parametric oscillator (OPO) crystal (3) which is arranged downstream of the first optical parametric oscillator (OPO) crystal (2) and is designed to generate, from the residual pump radiation, a second pair of further gain bands, in particular a signal band and an idler band.

The application discloses a kind of multi-wavelength pumped mid-infrared upconversion spectral detection methods, its characteristics are that the method uses multi-wavelength narrowband laser as the pump source of nonlinear conversion, simultaneously adopt multi-period quasi-phase matching crystal as nonlinear upconversion medium, realize mid-infrared signal broadband and efficient conversion, and combine high-performance near-infrared spectral measurement and control element, finally obtain wide band, high resolution, ultra-sensitive mid-infrared spectral detection.The application has the characteristics of large bandwidth and high efficiency compared with existing upconversion spectral technology, simultaneously can high fidelity resolution mid-infrared spectral information, for realizing wide band, high resolution, ultra-sensitive mid-infrared spectral measurement provides effective means, is expected to be applied to molecular spectroscopy, trace substance detection, infrared remote sensing and atmospheric monitoring and other important fields.

A laser communication terminal comprises a laser, a receiver, and a photonic integrated circuit (PIC) optically coupled to the laser and receiver. The laser communication terminal also includes multiple optical fibers. Each of the multiple optical fibers is optically coupled to the PIC and to a microlens array. Each of the multiple optical fibers is attached to the microlens array. The PIC can include multiple waveguides and multiple phase-matching elements, and each of the multiple waveguides can be optically coupled to a corresponding phase-matching element.

The invention belongs to the technical field of laser technology and nonlinear optical frequency conversion, and discloses an intelligent control method for a PPLN frequency multiplication system, which comprises the following specific steps: step 1, initializing and self-checking the system, and completing initialization of hardware peripherals and a control program after the system is powered on; according to the method, a three-stage progressive optimal working point searching process is adopted, and the problem of optimal matching temperature drift caused by crystal heat absorption and photorefraction effects under high-power operation is effectively solved through the modes of low-power coarse scanning calibration of reference temperature, gradient power approximation real-time tracking of temperature drift and high-power dynamic locking closed-loop control; it is ensured that the system can work in the optimal state of quasi-phase matching under any input power; and meanwhile, through a power-temperature synchronous coordination feedforward + feedback control strategy, an efficient conversion interval is always maintained in a system output power adjustment process, and sudden efficiency drop caused by mismatch is avoided.

The invention discloses an organic and inorganic compound crystal (H11C4N2) CdI3 as well as a preparation method and application thereof. The organic and inorganic compound crystal is a hybrid crystal, the chemical formula is (H11C4N2) CdI3, the organic and inorganic compound crystal belongs to a monoclinic system, the space group is Cc, and the cell parameters are as follows: a = 14.36-14.38, b = 7.13-7.15, c = 13.77-13.79, alpha = gamma = 90 degrees, beta = 121.2-121.4 degrees, and Z = 4. The crystal is prepared by a hydrothermal method. The organic-inorganic hybrid crystal has excellent second-order nonlinear optical performance, can output very strong 532 nm laser under 1064 nm laser irradiation, has a powder SHG coefficient 6 times that of KH2PO4 (KDP), can realize phase matching, and is a second-order nonlinear optical material with potential application value.

This invention relates to a germanium-based chiral perovskite second-order nonlinear optical crystalline material, its preparation and application, wherein the chemical formula of the material is ( R -C7H 10 NO)GeI3 and ( S -C7H 10 NO)GeI3, where R -C7H 10 NO is a (R)-2-(1-hydroxyethyl)pyridine cation. S -C7H 10 NO is a (S)-2-(1-hydroxyethyl)pyridine cation. This crystal belongs to the hexagonal crystal system, space group [space group number missing]. P 63, cell parameters a =17.0~18.0 Å, b =17.0~18.0 Å, c =7.0~8.0 Å, unit cell volume V =2000~2200 Å 3 , α = β =90°, gamma =120° Z= 2. Under 1200 nm laser irradiation, the nonlinear optical crystal of the present invention ( R -C7H 10 NO)GeI3 and ( S -C7H 10 The frequency doubling effect of GeI3 powder is 15 times that of KH2PO4; under 2000 nm laser irradiation, the frequency doubling effect of the crystalline material powder is 1.0 times that of KTiOPO4, and both can achieve phase matching. The crystalline material also has a large birefringence, wherein ( R -C7H 10 NO)GeI3 is 0.518 @ 546 nm, ( S -C7H 10 The NO)GeI3 has a wavelength of 0.529 nm at 546 nm and a moderate optical band gap (2.68 eV). The crystalline material of this invention shows significant engineering application value in nonlinear optical applications such as near-infrared laser frequency conversion, optical parametric amplification, and electro-optic signal processing.

The application discloses a nonlinear optical device based on ammonium fluoroborate crystal and a manufacturing method and application thereof, and the manufacturing method comprises the following steps: a, measuring the frequency doubling coefficient of the ammonium fluoroborate crystal; b, determining the effective frequency doubling coefficient formula of the ammonium fluoroborate crystal cut according to the phase matching angle; c, measuring the principal refractive index of the ammonium fluoroborate crystal at multiple wavelengths from deep ultraviolet to infrared, and fitting to obtain a Sellmeier equation; d, obtaining the type I or type II phase matching curve of the ammonium fluoroborate crystal by using the Sellmeier equation in step c, and determining the phase matching point of the ammonium fluoroborate crystal; and e, performing orientation, cutting, polishing of two light transmission surfaces and medium film plating on the ammonium fluoroborate crystal according to the phase matching direction to obtain a prism-free nonlinear optical device of the ammonium fluoroborate crystal. The nonlinear optical device can be obtained without the aid of a prism, and has a relatively high output power.

The application discloses a TBM rock slag form identification method and system, comprising: acquiring a rock slag depth image irradiated by structured light of different frequencies, decoding the structured light in the rock slag depth image to obtain the absolute phase of each pixel point, and performing phase matching on the pixel points; calculating a parallax value according to the matched pixel pairs, obtaining the depth corresponding to the pixel points according to the parallax value corresponding to the pixel points, obtaining the three-dimensional coordinates of each pixel point, and constructing a three-dimensional point cloud map; acquiring a rock slag color image without structured light irradiation, aligning the pixel points of the rock slag color image and the three-dimensional point cloud map, and obtaining a color point cloud; and identifying the position, size and type of the target rock slag by using a trained neural network on the color point cloud. The method meets the engineering requirement of quickly sensing the size of rock slag in the TBM tunneling process, and improves the identification accuracy and efficiency.

The application provides a fluorinated guanidinium borate nonlinear optical crystal and a preparation method and application thereof. The chemical formula of the crystal is [C(NH2)3]B6O9F, the molecular weight is 287.95, the crystal belongs to an orthorhombic system, the space group is Pnma, Pna 21, the cell parameter is a=7.8420(11) Å, b=15.1862(19) Å, c=8.5762(9) Å, α =90°, β =90°, γ =90°, the unit cell volume is 1021.3(2) ų, the crystal is grown by a high-temperature solution method or a flux method, the frequency doubling effect of the crystal is 0.4 times of that of KH2PO4 (KDP), the ultraviolet cutoff edge is 190 nm, the birefringence is large, the birefringence is 0.133 @ 1064 nm, and the deep ultraviolet phase matching capability is deep, the shortest matching wavelength is 196 nm, and the crystal can be applied to deep ultraviolet nonlinear optical crystals in a full solid-state laser.

The application relates to a preparation method of a four-fold frequency crystal guanidinium tetrafluoroborate device, which comprises the following steps: firstly, measuring a frequency doubling coefficient of the crystal by a Maker fringe method to obtain two non-zero effective frequency doubling coefficients; secondly, measuring main refractive indexes of the crystal at 11 wavelengths between 253 nm and 2325 nm by a minimum deviation angle method, and fitting a Sellmeier equation; thirdly, calculating a phase matching curve of the crystal I or II type by a computer program according to the Sellmeier equation, and combining the frequency doubling coefficient to determine a phase matching point of the crystal; fourthly, cutting the crystal according to the phase matching direction, polishing two light transmission surfaces, and coating a dielectric film to obtain the four-fold frequency crystal device; and the four-fold frequency crystal device is used for generating four-fold frequency laser output, the frequency doubling effect is 4.7 times that of KDP, and the four-fold frequency crystal device has good practical application value in the field of laser technology.

This invention discloses a high-efficiency nonlinear optical frequency converter based on high-power continuous optical transmission using quartz micro / nano fiber, comprising a wavelength-tunable laser, an optical fiber amplifier, a quartz micro / nano fiber, a sealed cavity, and an optical fiber low-pass filter; the quartz micro / nano fiber includes a first untapered portion, a second untapered portion, a first tapered transition region, a second tapered transition region, and a waist region, transmitting an optical field TE. 01 The mode cutoff method precisely controls the waist diameter of micro / nano fiber and accurately tunes the input light wavelength. The nonlinear light frequency conversion process excited by high-power continuous light transmitted in quartz micro / nano fiber satisfies perfect phase matching. The fundamental mode of the input light and the higher-order mode fields of the harmonic signal light have high overlap in the waveguide mode, which can efficiently generate continuous second and third harmonic signal light. The device has high stability, high efficiency, and low cost, and can be applied in fiber lasers, all-optical signal processing, fiber optic sensing and other fields.

The application provides a nonlinear optical crystal, a preparation method and application thereof, and has the chemical formula Y(C6H5SO3)3.9H2O, wherein the compound has good nonlinear optical performance, a band gap of 4.35eV, an ultraviolet cutoff edge near 285nm, a frequency doubling response of about 0.8 times of KH2PO4 (KDP), a shortest phase matching wave band near 300nm, good crystal growth habit, and simple preparation process and low preparation cost; the nonlinear optical crystal can be used for frequency conversion of laser output, the shortest phase matching wavelength is less than 300nm, and can produce 2 times frequency doubling harmonic output on a laser beam with a wavelength of 1064nm; meanwhile, the crystal can be used for a harmonic generator from an infrared region to an ultraviolet region, an optical parametric and amplifier device, an optical waveguide device and a nonlinear optical device, can meet a larger frequency doubling coefficient, has larger birefringence, and has wide application in the field of nonlinear optics.

The invention relates to a second-order nonlinear optical material crystal amino methanesulfonic acid as well as preparation and application thereof. The chemical formula of the crystal is O3SCH2NH3, the molecular weight of the crystal is 111.12, the crystal belongs to a monoclinic system, the space group of the crystal is Cm, the cell parameters are alpha = gamma = 90 degrees, beta = 129.7-131.7 degrees, Z = 2, and the cell volume of the crystal is structurally characterized in that the crystalline material is a three-dimensional frame formed by connecting [O3SCH2NH3] elements through hydrogen-bond interaction. The amino methanesulfonic acid crystal material has excellent optical performance, and under 1064nm laser irradiation, the powder frequency doubling intensity is about 3.8 times that of a KH2PO4 (KDP) crystal; under the irradiation of 532 nm laser, the frequency doubling strength of the powder is about 0.7 time of that of the beta-BaB2O4 (BBO) crystal, and phase matching can be realized. Besides, the crystal material has moderate birefringence at 546 nm, the ultraviolet absorption cut-off edge is smaller than 170 nm, and the crystal material has stable physical and chemical properties and has important application value in the photoelectric fields of photoetching, laser frequency conversion, environmental monitoring and the like.

This invention discloses a high-power, broadband, tunable long-wavelength mid-infrared femtosecond laser generation device and method. The laser beam is split into a first beam and a second beam. The first beam pumps a first YAG crystal to generate a first supercontinuum, from which a signal light of a predetermined wavelength is selected. The signal light undergoes at least two cascaded optical parametric amplification stages to generate a high-power mid-infrared pump light. The second beam pumps a second YAG crystal to generate a second supercontinuum covering the long-wavelength infrared band as a seed light. This seed light is then incident on a BGGSe crystal for optical parametric amplification. Using a 1.5μm high-power femtosecond laser as the pump source, combined with the BGGSe nonlinear crystal for optical parametric amplification, the wide transmission range and high nonlinear coefficient of the BGGSe crystal are effectively utilized. Phase matching in the 6–18μm band can be achieved under 1.5μm pumping conditions, thereby obtaining a broadband, high-power, femtosecond-level laser output covering the long-wavelength mid-infrared band.

Non-classical light is generated from classical light by providing a non-classical light generation stage with at least one waveguide; inputting classical light into the non-classical light generation stage; and converting at least part of the classical light into non-classical light. The classical light is in a non-fundamental propagation mode of a waveguide of the non-classical light generation stage, and the non-classical light is in a fundamental propagation mode a waveguide of the non-classical light generation stage. The converting does not involve quasi-phase-matching. An input adaptation stage obtains classical light for input into the non-classical light generation stage. In the input adaptation stage, classical light is converted into classical light of a different waveguide propagation mode. A system has a non-classical light generation stage for converting classical light at least partly into non-classical light, and an optical switch and / or an optical phase shifter, arranged on a single optical chip.

This invention discloses an optically pumped tunable vertical-cavity surface-emitting laser (VCSEL), a mirror, and their applications. The wavelength-selective mirror includes a phase-matching region and an optimization region arranged sequentially along the vertical direction. The phase-matching region is formed by periodically alternating stacks of x pairs of first high-refractive-index material layers and first low-refractive-index material layers along the vertical direction. The optimization region is formed by y pairs of second high-refractive-index material layers and z pairs of second low-refractive-index material layers, which are alternately stacked along the vertical direction, and the optical thicknesses of the second high-refractive-index material layers and the second low-refractive-index material layers are unequal. This invention breaks away from the traditional single optimization paradigm centered on lasing light in DBRs, significantly improving optical pumping efficiency while ensuring a wide tuning range and free spectral range, thereby realizing a highly efficient wide-tunable single-longitudinal-mode output MEMS-VCSEL, laying the foundation for next-generation high-performance tunable lasers.