674results about "Laser output parameters control" patented technology

The invention discloses a wavelength-tunable electro-absorption modulated laser and a preparation method thereof. The laser comprises a substrate, and a first modulator region, a first gain region, a grating region, a second gain region and a second modulator region which are sequentially arranged on the substrate and are positioned on the same plane, phosphorus ions are doped in constituent materials of the first modulator region and the second modulator region. The first gain region and the second gain region are used for exciting laser with various wavelengths under the action of different direct currents; the grating area is used for carrying out mode selection on the various wavelengths; the first modulator area and the second modulator area serve as light emitting ends to emit tunable laser, and double-end laser emission is achieved. The two electro-absorption modulators and the wavelength tunable laser are integrated back to back, a wavelength tuning area is shared, and bandwidth doubling is achieved. Through epitaxial growth of one-time active material and one-time passive material, integration of three forbidden bandwidth materials is realized, the manufacturing process is simplified, and the performance of the device is improved.

The invention relates to the technical field of laser temperature control, in particular to a temperature control method and system for a multi-environment VCSEL laser, and the method comprises the steps: collecting the temperature of the VCSEL laser at each moment, and the current of a thermoelectric refrigerating unit used for carrying out the temperature control of the VCSEL laser at each moment; determining the temperature fast adjustment intensity and the temperature oscillation characteristic value of the VCSEL laser at each temperature control moment; obtaining a steady state adjustment value of the VCSEL at each temperature control moment; determining the magnetic field interference suppression intensity of the VCSEL laser at each temperature control moment; and correcting a first threshold value and a second threshold value of the integral separation PID control algorithm, determining a switching coefficient of an integral item in the integral separation PID control algorithm, and performing temperature control on the VCSEL at each temperature control moment. Therefore, the temperature control precision of the VCSEL laser is improved.

The invention relates to the technical field of laser control, in particular to a light spot consistency control method and system for DFB lasers, and the method comprises the steps: obtaining the current and temperature of each DFB laser at each moment in each control period; calculating the burr saliency, the temperature rise drift coefficient, the temperature drop drift coefficient and the heat source interference value of each DFB laser in each control period; and determining expansion and contraction factors of a positive universe and a negative universe in the fuzzy control algorithm, and controlling the temperature of the DFB laser in real time so as to control the light spot consistency of the DFB laser. According to the method and the device, by selecting the proper telescopic factor and dynamically adjusting the discourse domain range of the fuzzy control algorithm, the response speed of temperature control of the DFB laser is improved, the temperature of the DFB laser is controlled more accurately, and light spot consistency control is realized.

The invention provides a patterned photonic crystal laser and a preparation method thereof, the laser comprises a substrate, and a first mask layer, a photonic crystal layer and a second mask layer which are sequentially deposited on the substrate, a light emitting area is etched in the central area of the second mask layer, and transparent conductive layers are deposited on the surface of the second mask layer and the light emitting area; a p-annular electrode is arranged on the surface of the transparent conductive layer on the second mask layer, and an n-annular electrode is arranged below the substrate; the photonic crystal layer is composed of a nanorod array and a polymer filled in gaps of nanorods; holes distributed in a patterned array are etched in the surface of the first mask layer, and nanorods are epitaxially grown in hole areas; the nanorod is formed by sequentially depositing a substrate contact layer, a first waveguide layer, a multi-quantum well layer, a second waveguide layer, a coating layer and a component gradient layer. According to the invention, through collaborative design optimization of all the layers, emission of laser with specific wavelength and preparation of a laser emitting laser with single longitudinal mode, narrow linewidth and stable wavelength are realized.

The invention discloses an on-chip time-frequency transmission system and method based on an octave optical comb and an electro-optical modulation optical comb, and the method comprises the steps: constructing a chip-based optical reference cavity through the technologies of vacuum optical cement, photoresist backflow and the like, and achieving an on-chip ultra-stable laser through a phase modulator and a reflection separation optical path; an on-chip laser source pumping micro-ring resonant cavity is utilized to generate an octave optical frequency comb, frequency multiplication is carried out on the on-chip laser source pumping micro-ring resonant cavity and an additional laser source to realize detection and locking of carrier envelope offset frequency (fceo), frequency beating is carried out on the on-chip laser source pumping micro-ring resonant cavity and the on-chip ultra-stable laser device to realize frequency beating (fbeam) locking, and the laser source is utilized to generate an electro-optical modulation optical frequency comb through a circulating phase modulator to realize frequency beating and locking of the on-chip ultra-stable laser device. And the optical time frequency is locked with the locked octave optical comb, is sent to a far end after polarization control and light amplification, and simultaneously receives an electro-optical modulation optical comb at the far end and performs linear light sampling, so that the transmission of the optical time frequency is realized. The optical fiber or space optical link time-frequency transmission device can realize optical fiber or space optical link time-frequency transmission, and has the advantages of low overall noise, high transmission precision, compact structure, small size, low power consumption and the like.

The invention provides a topological polygonal laser. According to the device, a topological non-trivial domain formed by two-dimensional gyromagnetic photonic crystals is combined with a trivial domain, and an out-of-plane magnetic field externally applied to a sublattice A is started to open an energy band gap, so that a multi-position angular state is realized. The two-dimensional gyromagnetic photonic crystal opens or closes an out-of-plane magnetic field externally applied to the sub-lattice A so as to realize opening and closing of the angular state of the topological angular state laser. The topological multi-angular-state laser is realized by taking the two-dimensional gyromagnetic photonic crystal as a platform, and the topological multi-angular-state laser has the advantages that switching of angular states can be realized without changing the structure, and the laser is topologically protected and has topological robustness.

A self-calibrating driver circuit (100, 300, 400, 500, 700) for a laser diode is disclosed. The circuit comprises a configurable current source (105, 305, 405, 505), a current mirror (115, 315, 415) configured to mirror a current from the configurable current source to a first transistor (120, 320, 420, 520, 720) and to a second transistor (125, 325, 425, 725), and a control circuit (140, 340, 440). The control circuit is configured to monitor a current through the first transistor at a first time, and to configure the current source based on the current through the first transistor to provide a desired current to the second transistor for driving the laser diode at a subsequent second time. A radiation-emitting device comprising one or more of the self-calibrating driver circuits and at least one radiation-emitting element is also disclosed.

The embodiment of the invention provides a laser array and a laser radar, and relates to the technical field of optical perception. The differential resistance of the laser array is adjustable, and the optical power of the output emitted laser is adjustable. The laser array comprises a first laser and a second laser; the first laser comprises a first reflecting layer, a first active layer and a second reflecting layer which are sequentially arranged along the epitaxial direction, and a first oxidation hole is formed in the second reflecting layer; the second laser comprises a third reflecting layer, a second active layer and a fourth reflecting layer which are sequentially arranged in the epitaxial direction, a second oxidation hole is formed in the fourth reflecting layer, and a light blocking layer is further arranged on the side, away from the second active layer, of the fourth reflecting layer. The projection of the light blocking layer on the second active layer is overlapped with the projection of the second oxidation hole on the second active layer; the first laser is electrically connected with the second laser.

The invention relates to the technical field of semiconductor lasers, in particular to a semiconductor laser with an adjustable time domain. According to the time-domain-adjustable semiconductor laser, a mutual injection coupling region and a gain region are arranged on a semiconductor laser chip, the mutual injection coupling region comprises multiple sections of interval units, and the ratio of the length of a saturable absorber region to the length of the gain region in a resonant cavity is controlled by adjusting the absorption / gain characteristics of the interval units. And a plurality of pulse generation mechanisms are switched to adjust the pulse width. On the premise that the structural complexity of the semiconductor laser is reduced, large-range adjustment of laser pulses can be achieved.

The invention belongs to the field of ultrafast laser design and hyperspectral imaging, and provides an active spectrum modulation ultrafast laser and a hyperspectral detection system and method thereof, and the technical scheme is that the active spectrum modulation ultrafast laser comprises an ultrafast pulse laser, a primary polarization modulation module, a nonlinear broadening module and a secondary polarization modulation module; narrow-spectrum pulse laser emitted by the ultrafast pulse laser enters the nonlinear broadening module to be subjected to spectrum broadening to obtain wide-spectrum pulse laser after being subjected to preliminary modulation of the polarization state of laser of all wave bands through the preliminary modulation module, and the wide-spectrum pulse laser emitted by the nonlinear broadening module enters the secondary polarization modulation module to be subjected to spectrum broadening to obtain wide-spectrum pulse laser. And after randomizing the polarization state of each spectrum, irradiating the spectrums to a target scene. After the spectrum is modulated, the camera is controlled to collect the reflectivity intensity information of the target scene, and after irradiation and image collection of multiple groups of selected spectrum structures are completed, hyperspectral detection of the target scene is achieved in combination with the measured spectrum distribution and the corresponding reflectivity information.

An improved external cavity laser (1) is provided herein that comprises a gain section (2) and an external cavity passive chip (3) with a first end (31) that is optically coupled to the gain section (2) and with a second end (35) providing a laser output, the external cavity passive chip (3) having a cavity (33) between the first end (31) and a phase shifted Bragg grating, FBG (34).

The invention discloses an automatic wavelength tuning method and system for a tunable laser based on particle swarm optimization, and is applied to the technical field of wavelength tuning of semiconductor tunable lasers. According to the method, a particle swarm optimization (PSO) algorithm is taken as a core, multi-target iterative search optimization is carried out on initial current-wavelength data, and in a tuning initialization stage, a system firstly carries out coarse scanning on three paths of current of a left reflecting grating region, a right reflecting grating region and a phase modulation region of a sampling grating distributed Bragg reflection laser; manual intervention is not needed, the system can complete efficient configuration screening in a given target wavelength range, the intelligent level of the tuning system is remarkably improved, good automation capacity and expansibility are achieved, scanning of a large number of invalid data and tedious operation procedures in the traditional tuning process are avoided, and the tuning efficiency is improved. And meanwhile, a high-quality current-wavelength lookup table can be quickly constructed, and the method has wide engineering application prospects in optical communication, sensing and other scenes.

The invention discloses a directly-modulated wavelength scanning light source device which comprises a pulse control unit, a semiconductor laser, a thermoelectric refrigerating unit, a temperature measuring element, a temperature control system, a coupler, a wavelength calibration element, a photoelectric detector and a wavelength correction system. The pulse control unit drives the semiconductor laser, the semiconductor laser is connected with a first input end of the coupler, a first output end of the coupler is connected to the wavelength calibration element, a second input end of the coupler is connected with the photoelectric detector, and the photoelectric detector is connected with the pulse control unit. A second output end of the coupler is a wavelength scanning light source output end, and the photoelectric detector is connected with the wavelength correction system. The device realizes a light source in a wavelength scanning range from several nm to dozens of nm at a wavelength scanning rate as high as MHz and above, realizes wavelength scanning in each wave band range based on a directly modulated laser, and is beneficial for adapting to more optical fiber sensing high-speed measurement application occasions.

Embodiments of the present application relate to the technical field of optical sensing, and provide a laser array and a laser radar. The differential resistance of the laser array is adjustable, and the optical power of output emitted laser light is adjustable. The laser array comprises a first laser and a second laser; the first laser comprises a first reflecting layer, a first active layer, and a second reflecting layer which are sequentially arranged in an epitaxial direction, and a first oxidation hole is formed in the second reflecting layer; the second laser comprises a third reflecting layer, a second active layer, and a fourth reflecting layer which are sequentially arranged in the epitaxial direction, a second oxidation hole is formed in the fourth reflecting layer, a light blocking layer is further provided on the side of the fourth reflecting layer away from the second active layer, and the projection of the light blocking layer on the second active layer overlaps the projection of the second oxidation hole on the second active layer; the first laser is electrically connected to the second laser.

The invention relates to a photoelectric integrated double-frequency laser for coherent wind measurement, which comprises a first light source module, a second light source module, a first coupler module, a second coupler module, a third coupler module, a first beam splitter module, a second beam splitter module, a third beam splitter module and a first balanced photoelectric detector module, a second balance photoelectric detector module, a modulator module, an optical phase-locked loop module and a transceiver. Based on the silicon-based optoelectronic chip technology and the photoelectric hybrid packaging technology on the structural level, the coupler, the beam splitter and the photoelectric detector are integrated on the silicon optical chip, and the silicon optical chip, the DFB chip, the coupling optical path, the electrical module and the like are packaged together by utilizing the photoelectric hybrid packaging technology, so that high-density integration is realized; a heterodyne digital optical phase-locked loop technology is applied to a system level, so that a specific frequency difference exists between output signal light and reference light, and pulse light with a high extinction ratio is generated in a modulator cascading mode. Compared with a conventional single-light-source system scheme, the heterodyne Doppler wind measurement laser radar system can greatly improve the integration level, reduce the power consumption and the cost, and is beneficial to mass production, and compared with a homodyne detection mode, heterodyne detection is higher in measurement speed, simpler in scheme and better in stability. The system has extremely high expansibility, and can be applied to systems of optical fiber sensing, laser remote sensing and cold atomic clocks through operations of replacing a transmitting-receiving device, modifying a control program and the like.

The invention discloses a narrow linewidth laser frequency control device and method based on optical feedback discretization, and belongs to the technical field of laser control. In order to solve the problems of poor frequency stability and tuning range of an existing laser, a laser beam emitted by the laser is incident to an optical feedback assembly to generate front-cavity mirror transmission light; the optical heterodyne feedback adjusting assembly demodulates an electric signal corresponding to the transmission light of the cavity front mirror to obtain an error signal, and transmits the error signal to the high-voltage amplification control module end to control the PZT, so that the high-voltage amplification control module end controls the PZT according to the error signal to lock the laser frequency on the cavity mode frequency; and meanwhile, the laser controller changes the working current of the laser, so that the laser frequency is locked on each intrinsic cavity mode frequency of the optical resonant cavity, and a series of discrete wide-range stable locking frequencies are obtained under the control of the temperature control module.

A semiconductor laser (1) comprising a semiconductor body (2) with an active region (20) for generating radiation (8) and an optical interaction structure (3) with structural elements (30) is specified, wherein at least some of the structural elements (30) are arranged at different nominal center distances (35) to each other such that, during operation of the semiconductor laser (1) at a given operating point, local temperature differences in the optical interaction structure (3) reduce differences between the optical path lengths (39) that are assigned to the nominal center distances (35) of these structural elements (30). Furthermore, a method for manufacturing a semiconductor laser (1) is described.

A distributed feedback (DFB) laser apparatus has a distributed feedback (DFB) laser (650) comprising a DFB structure (511), a heater (508) arranged to heat the DFB structure to change a lasing frequency of the DFB laser and a heater circuitry hard-wiring configuration (556) hard-wired to route power to a selected portion (616) of the heater such that heating the selected portion (616) changes refractive index of the DFB structure (511) at a position along the DFB structure corresponding to the selected portion, thereby adjusting the lasing frequency.

The invention relates to the technical field of laser, in particular to a high-signal-to-noise-ratio modulation transfer spectrum frequency stabilization light path system. The system comprises a laser, an optical isolator, a first half-wave plate, a first polarization splitting prism, an optical fiber coupler, a second half-wave plate, a second polarization splitting prism, a first reflecting mirror, an electro-optical modulator, a second reflecting mirror and a third polarization splitting prism, wherein the first half-wave plate is used for adjusting the power of frequency stabilization light; the second half-wave plate is used for adjusting the power ratio of pump light to probe light; a first quarter-wave plate, a second quarter-wave plate, an atomic gas chamber and a photoelectric detector; after the output of the laser is isolated by the optical isolator, the first half-wave plate and the first polarization splitting prism are matched to adjust the frequency stabilization total beam power to about 5mW; the pump light is modulated by the electro-optical modulator, the probe light and the pump light reversely interact in the atomic gas chamber in an anti-phase circular polarization state, and the signal-to-noise ratio of a modulation transfer signal and the stability of a frequency stabilization system are remarkably improved.

An ultraviolet (UV) light source includes a light emitting element that is configured to generate light of a first frequency, a nonlinear optical element that is configured to receive the light of the first frequency from the light emitting element and generate UVC or far-UVC light of a second frequency from the light of the first frequency, and an output coupling element that is configured to selectively outcouple the UVC or far-UVC light from the nonlinear optical element as output light. Related light sources and fabrication methods are also discussed.

The utility model provides a laser control device and wafer detection equipment. The laser control device comprises a laser, incident laser is emitted to a to-be-detected workpiece along an incident light path, and the incident laser forms reflected laser on the to-be-detected workpiece along a reflected light path; the light on-off element is arranged on the incident light path and used for controlling on-off of the incident laser; and the detection element is arranged on the reflected light path, is linked with the light on-off element and is used for detecting the reflected laser so as to enable the light on-off element to act. The laser control device comprises a laser device, a light on-off element and a detection element, reflected laser is detected through the detection element, on-off of an incident light path is controlled through the light on-off element, when the incident laser exceeds a working area, the incident laser can be shielded, propagation of the incident laser is blocked, potential safety hazards are eradicated, propagation of the reflected laser can be blocked, and the laser control efficiency is improved. Potential safety hazards of laser reflection are eliminated, and stability of laser output by the laser can be ensured.

This specification discloses a converter element and light emitting devices including the converter element. The converter element is monolithic with at least two layers, where one layer is more porous than the other layer. The converter element may be integrated with a reflector layer, such as by metallization. The layer of the converter structure that is denser and having a smoother surface may be the one that is metallized, while the more porous layer is closer to the laser. The porosity enhances light extraction while the smoother surface decreases a loss of reflectivity at the reflector-phosphor interface. The converter element may be used in a laser based light emitting device.

Devices, methods and techniques related to the use of a photoconductive semiconductor switch (PCSS) to drive a high-power laser diode for a wide range of pulse widths are disclosed. In one example aspect, a circuit for driving one or more laser diodes includes an input port configured to be coupled to a voltage input, one or more inductors that are configured to be in series with the one or more laser diodes, a photoconductive switch coupled with the one or more inductors, and an output port configured to be coupled to the one or more laser diodes.

The invention belongs to the technical field of single-photon emitters, and relates to a radiation-enhanced single-photon emitter and a preparation method thereof. The radiation-enhanced single-photon emitter comprises an hBN thin layer and an emitter; the emitter is disposed over the hBN thin layer, and the emitter is located within a range of 10 nm over the surface of the hBN thin layer. By using the hyperbolic dispersion characteristic of the hBN thin layer, the enhancement of the Purcell and the enhancement of the photon coupling output power can be realized in a broadband range. The single-photon emitter solves the problems that in an existing single-photon emitter, the photon Pelsel effect is enhanced, and the photon coupling output efficiency is low. Therefore, the application range of the material in photonics and quantum optics is expanded. Compared with an existing single-photon emitter, the single-photon emitter is simple in structure, does not need a complex manufacturing process, and reduces the manufacturing cost.

The invention provides a diffraction type surface-emitting semiconductor laser and a preparation method thereof. The diffraction type surface-emitting semiconductor laser comprises an active layer and complementary optical modulation layers located in one or more of an upper cladding, an upper waveguide layer, a lower waveguide layer and a lower cladding, and the complementary optical modulation layers comprise an upper optical modulation layer and a lower optical modulation layer; the lower optical modulation layer is provided with a first optical modulation material and a second optical modulation material which have different refractive indexes, and the two types of optical modulation materials form a high-low refractive index difference; the upper optical modulation layer is provided with a third optical modulation material and a fourth optical modulation material which are different in refractive index, and the two types of optical modulation materials form a high-low refractive index difference; in the direction perpendicular to the laser emitting face, the area where the second optical modulation material is located corresponds to the area where the fourth optical modulation material is located, and the area where the first optical modulation material is located corresponds to the area where the third optical modulation material is located.

The invention discloses an on-chip integrated high-power U-band multi-wavelength high-speed laser chip, which relates to the technical field of chip processing, and specifically comprises a P-Si substrate, an epitaxial transition buffer layer, a buffer layer structure, a laser gain region, a waveguide structure, a grating structure region and a ridge waveguide structure. Multi-wavelength high-speed laser is realized on a single chip, beam combination and amplification are realized, different inclined waveguides are adopted to correspond to different grating periods and light emitting wavelengths, multiple target wavelengths can be realized on the single chip through calculation, the laser can simultaneously output four wavelengths of 1621nm, 1641nm, 1661nm and 1681nm by reasonably setting the inclination angles of the ridge waveguides, and the performance of the laser can realize 100G long-distance transmission. A traditional discrete optical device is replaced; the epitaxial P-type substrate and the coplanar electrode are adopted to effectively reduce the series resistance and the heating power consumption of the device, and the multi-path combined high-speed laser is further amplified through the SOA.

The invention relates to the technical field of lasers, in particular to a narrow-linewidth frequency conversion laser which comprises a DFB laser, a first end of the DFB laser is used for outputting initial fundamental frequency light; the lithium niobate outer cavity comprises a spot size converter, a transmission waveguide provided with a phase shift part, a first multi-mode interference coupler, upper and lower speech channel micro-rings, a second multi-mode interference coupler and a periodically poled waveguide which are connected in sequence, and the upper and lower speech channel micro-rings and a Bragg grating of the DFB laser form a resonant cavity; the upper and lower speech channel micro-rings reflect a part of the received light back to the DFB laser to realize self-injection locking and output the other part of the received light to the second multimode interference coupler, the fundamental frequency light passes through the periodically polarized waveguide to realize frequency conversion, and the output end of the periodically polarized waveguide outputs frequency-doubled light; the lithium niobate outer cavity further comprises two comb-shaped electrodes which are symmetrically arranged on the two sides of the periodically poled waveguide. The performance of the narrow-linewidth frequency conversion laser can be improved at least.

A lithium niobate (LN) external cavity includes a Vernier mirror structure which includes two or more microresonators where: one or more or all of the Vernier microresonators are tuned by the electro-optic Pockels effect of LN, with tuning electrodes integrated with the resonators, and one of the Vernier microresonators could be tuned by the thermo-optic effect, with a local heater integrated with the resonator. One or more or all of the Vernier microresonators include a section or the whole resonator that is periodically poled to achieve quasi-phase matching for nonlinear frequency conversion directly inside the laser cavity. The lithium niobate (LN) external cavity also includes a phase shifter whose phase is tuned by the electro-optic Pockels effect of LN. A Sagnac loop mirror is placed at the end of the device to function as the output end mirror of the laser cavity.

The invention discloses a novel laser mode hopping compensation method. The method comprises the following steps that S1, a constraint bent groove for limiting a steel ball to move under KHz-level vibration is designed; s2, detecting a mode hopping phenomenon and parameters in laser output; s3, outputting a round-trip optical path adjustment amount and a curved groove Y-axis sinkage amount based on the mode hopping parameters obtained in the S2; s4, the corresponding position of the constraint bent groove designed in the S1 is polished and optimized based on the adjustment amount obtained in the S3; and S5, iteratively executing compensation until the laser output has no mode hopping. The invention is characterized by providing a novel mode-hopping compensation external cavity semiconductor laser system and a compensation method which are especially suitable for a TDLAS-WMS technology and can accurately sense the type and concentration of gas to be detected.

A semiconductor laser chip (1) comprising a semiconductor body with a sequence of semiconductor layers (2) having an active region (20) for generating radiation is specified, wherein the semiconductor body has a resonator region (3) with the active region (20) and a diode region (4) spaced apart from the resonator region (3), wherein the active region (20) of the resonator region (3) and the diode region (4) are connected antiparallel to each other with respect to their forward direction. Furthermore, a semiconductor laser arrangement (10) with a semiconductor laser chip (1) is specified.