1458 results about "Resonant cavity" patented technology

The invention discloses a low-power-consumption photonic integrated device preparation method and a corresponding device, and relates to the technical field of semiconductor optoelectronic integrated devices.The device comprises a substrate, a cantilever beam type grating layer, two gain layers, two modulator layers, a wrapping layer and an electric contact layer, the two gain layers and the two modulator layers are symmetrically distributed, and the wrapping layer and the electric contact layer form a shallow ridge waveguide structure. The two symmetrically-distributed gain layers and the middle cantilever beam type grating layer jointly form a double-end resonant cavity structure, the structure shares a unified grating and a thermal tuning platform to achieve continuous, synchronous and high-precision control over cavity mode wavelengths, and balanced modulation and phase synchronization of double-end output are achieved in cooperation with the symmetrically-integrated high-speed modulator layers on the two sides. According to the technical scheme, the gain layer, the grating layer and the modulator layer are symmetrically integrated on the same substrate, the alignment error of a multi-cavity structure is reduced, synchronous scanning, low drift and strong anti-interference high-quality laser output can be obtained, meanwhile, efficient thermal tuning is conducted through the cantilever beam type grating layer, and power consumption is remarkably reduced.

The invention discloses a mixed gas absorption spectrum analysis method and system based on variational mode decomposition, specific laser is injected into an optical resonant cavity unit, and a detector unit continuously monitors the light intensity change and records a light intensity attenuation signal; pre-processing the recorded light intensity attenuation signal; carrying out VMD decomposition on the preprocessed ring-down signal to obtain a plurality of IMF components, respectively introducing CO2 and CO gases with known concentrations into the optical resonance unit, and recording spectral data of each single gas component; calculating the similarity and contribution degree of each IMF component, and setting a weight combination to form a joint score; the gas with the highest joint score is selected, the score is compared with an adaptive threshold value, and when the score is higher than the adaptive threshold value, the IMF component is marked as the characteristic component of the corresponding gas; and finally, gathering and outputting the marked IMF components according to gas types to obtain characteristic signals of the gases, thereby realizing multi-component gas separation in the mixed gas absorption spectrum.

The invention discloses a multi-channel runway micro-ring modulator capable of adjusting coupling efficiency, and the modulator comprises a runway micro-ring resonant cavity which comprises a straight waveguide section and a bent section and is used for achieving the resonance of an optical signal; the Mach-Zehnder modulation structure is integrated with the micro-ring resonant cavity and is used for adjusting the equivalent coupling coefficient of the micro-ring and the main waveguide; wherein the Mach-Zehnder modulation structure comprises a coupler, a mode converter and a modulation arm. And the modulator is also provided with a heater. According to the scheme, the coupling coefficient of the micro-ring resonant cavity and the main waveguide is adjusted through the Mach-Zehnder modulation structure, the limitation of the photon lifetime of the micro-ring resonant cavity on the modulation rate is overcome, and the restrictive relationship between the bandwidth and the modulation efficiency is broken. Compared with an existing micro-ring modulator, the micro-ring modulator can still have the high-speed modulation capacity in a high-quality-factor micro-ring resonant cavity. Meanwhile, through the design of the waveguide in the Mach-Zehnder interference region, the length of the modulation region is increased while the area of the device is not increased.

The invention discloses a reconstruction spectral imaging system based on an electromagnetic drive Fabry-Perot resonant cavity, and belongs to the field of spectral imaging. The system comprises an optical lens group, an electromagnetic driving device, a Fabry-Perot resonant cavity, a photoelectric detection array and a calculation unit, the cavity length of the Fabry-Perot resonant cavity can be adjusted through the electromagnetic driving device. The optical lens group receives light reflected or emitted by an external to-be-measured target scene and carries out collimation processing, and then the light enters the Fabry-Perot resonant cavity. The Fabry-Perot resonant cavity screens the incident light based on the resonance condition of the cavity length of the Fabry-Perot resonant cavity, and the screened light is emitted to the photoelectric detection array; the photoelectric detection array converts the incident light intensity into an electric signal and outputs the electric signal to the calculation unit; and a spectrum reconstruction model is built in the calculation unit, and a hyperspectral image of the to-be-measured target scene is obtained by using the spectrum reconstruction model based on the electric signal. The working range and the spectral imaging precision of the spectral imaging system based on the Fabry-Perot resonator are improved, the technological requirements are reduced, and the engineering applicability of the spectral imaging system based on the Fabry-Perot resonator is improved.

The invention relates to the technical field of lasers, in particular to a multi-chip vertical external cavity surface emitting laser which comprises a chip set, a first prism, a second prism and an output coupling mirror which are sequentially arranged along a preset central axis. The chipset comprises N gain chips, and the N gain chips output N sub light beams; the N sub-beams pass through the first prism, the sub-beams emitted from the first prism converge towards a preset central axis, the sub-beams are incident to the second prism before convergence and are combined into a resonant beam through the second prism, the resonant beam resonates in a resonant cavity formed by the output coupling mirror and the chip set, and the output coupling mirror and the chip set form a resonant cavity; the output laser is emitted from the output coupling mirror; wherein N is greater than 1. The invention is beneficial for solving the problems that the power of a single chip is limited, the beam combining efficiency is low, only incoherent beam combining can be realized, and a multi-chip beam combining structure is complex.

The embodiment of the invention provides a dual-frequency base station antenna, and belongs to the technical field of antenna equipment, the dual-frequency base station antenna comprises a grounding plate, two dielectric substrates are laminated on the grounding plate, each dielectric substrate is correspondingly provided with a radiation unit, and the radiation signal frequency bands of the two radiation units are different; the radiation unit comprises a radiation patch and a metal through hole array which are arranged on the dielectric substrate, the radiation patch is a fan-shaped patch, the metal through hole array is arranged around the arc-shaped edge of the radiation patch, and the metal through hole array, the grounding plate, the dielectric substrate and the radiation patch jointly form a substrate integrated waveguide resonant cavity; the substrate integrated waveguide resonant cavity is configured to couple and excite the radiation patch after being externally excited so as to radiate a signal of a preset frequency band through the radiation patch. The dual-frequency base station antenna provided by the embodiment of the invention has excellent pilot frequency isolation performance, and can realize bandwidth expansion and radiation optimization effects.

The invention discloses an optical interconnection system which comprises a light source, a transmission medium and a photoelectric detector. The light source adopts a micro resonant cavity light-emitting diode array, and the transmission medium adopts a multi-core plastic optical fiber. An optical signal output by the micro resonant cavity light emitting diode array is transmitted to the photoelectric detector through the multi-core plastic optical fiber and is converted into an electric signal through the photoelectric detector. The light source of the optical interconnection system provided by the embodiment of the invention adopts the micro resonant cavity light-emitting diode array, the transmission medium adopts the multi-core plastic optical fiber, and good balance among low power consumption, high stability and high parallelism can be achieved through component optimization.

The invention discloses a radio frequency closed-loop decoupling device and method, and the device comprises a radio frequency sampling module which collects a radio frequency signal of a resonant cavity and converts the radio frequency signal into an intermediate frequency signal; the preprocessing module is used for converting the intermediate frequency signal into an I-path signal and a Q-path signal; the extended state observation module is used for obtaining an I component estimated value, a Q component estimated value and a corresponding generalized disturbance estimator according to the I-path signal and the Q-path signal; the decoupling control module is used for carrying out proportional control according to the I component estimation value and the Q component estimation value, and taking the generalized disturbance estimation quantity as decoupling compensation quantity for superposition to obtain a baseband signal so as to suppress channel coupling and external disturbance; and the radio frequency driving module is used for converting the baseband signal into a driving signal so as to control the amplitude and the phase of the radio frequency output of the power source. According to the invention, dynamic decoupling of the I signal channel and the Q signal channel is realized, and the stability and the control precision of the output amplitude and the phase of the power source are improved.

The invention relates to a micro-ring resonator based on a multi-circle square structure, the micro-ring resonator comprises a coupling waveguide and a multi-circle square micro-ring resonant cavity, the coupling waveguide comprises an S-bend waveguide, an input waveguide and an output waveguide which are all single-mode waveguides, and the multi-circle square micro-ring resonant cavity comprises a crossed waveguide chain and a multi-mode waveguide section connected with the crossed waveguide chain. The multi-mode waveguide section comprises a multi-mode straight waveguide and a 90-degree multi-mode Euler bending waveguide. By introducing the multi-mode waveguide, the energy distribution of the guided mode on the side wall is reduced, and the transmission loss of the micro-ring resonant cavity is reduced. Through the arrangement of the multi-circle square micro-ring resonant cavity, the length of the micro-ring is increased within a limited size, and the Q value of the multi-circle square micro-ring resonant cavity is improved. By means of the 90-degree multimode Euler bending waveguide, compact 90-degree turning is achieved, generation of a high-order mode is restrained, and meanwhile the micro-ring surrounding area is increased. Therefore, a solution can be provided for the high-performance sensing unit for the integrated micro-ring sensor.

The invention relates to the technical field of superconducting cyclotrons, and discloses a spiral resonant cavity for a superconducting cyclotron, which comprises an upper resonant cavity body and a lower resonant cavity body, and the upper resonant cavity body is positioned right above the lower resonant cavity body; through distributed waterway design and structural optimization, the cooling system can effectively process heat generated in the accelerator; efficient heat dissipation of the system is ensured through design means such as a multi-directional cooling channel, an oxygen-free copper brazing pipeline and a double-path independent cooling pipe, excessive accumulation in a high-temperature area is avoided, and meanwhile the stability of equipment can be kept in long-time operation; the structure of the single inner rod is convenient for voltage distribution adjustment, the structure is simple and compact, and the processing complexity and the manufacturing cost are greatly reduced; a core component solution with high reliability and low operation and maintenance cost is provided for the superconducting cyclotron, and application efficiency upgrading in the fields of medical treatment, scientific research and the like is promoted.

A first pumping source and a second pumping source are combined through a pumping beam combiner and are coupled into an erbium-doped fluoride fiber and a high-reflectivity fiber bragg grating, and the erbium-doped fluoride fiber and a low-reflectivity fiber bragg grating form a laser resonant cavity. The intermediate infrared laser is output through the low-reflectivity fiber bragg grating, the cladding light filter and the optical fiber end cap; the high-reflectivity fiber bragg grating and the low-reflectivity fiber bragg grating have the same grating period, the fourth-order harmonic reflection wavelength of the grating is located in the emission spectrum range of transition of erbium ions from the 4F9 / 2 energy level to the 4I9 / 2 energy level, and the fifth-order harmonic reflection wavelength of the grating is located in the emission spectrum range of transition of erbium ions from the 4I11 / 2 energy level to the 4I13 / 2 energy level; by adjusting the power of the first pumping source and the second pumping source, the net gain of laser transitions from the 4F9 / 2 energy level to the 4I9 / 2 energy level and transitions from the 4I11 / 2 energy level to the 4I13 / 2 energy level is regulated and controlled, and switching of laser working wavelengths is achieved.

The invention provides a method and a system for realizing a weak measurement enhanced chip-level microcavity gyroscope. The method comprises the following steps of: 1, providing a coherent state input by a system by using a single-frequency laser; 2, the output of the single-frequency laser is switched between a first path and a second path through an optical switch, the laser beam is transmitted to the first path in the first half part of the period, and the laser beam is transmitted to the second path in the second half part of the period; 3, the light transmitted along the first path and the second path respectively passes through an optical resonant cavity to sense the rotation angular speed, and a weak value amplification effect is achieved by setting front and back selection states; and step 4, weak measurement enhanced output results transmitted along the first path and the second path are respectively received by a photoelectric detector, and the value of the rotation angular velocity is demodulated according to the obtained output results. According to the invention, the optical microcavity is used as a sensing unit of the gyroscope, the sensing performance of the integrated optical gyroscope is greatly enhanced through a weak measurement technology, and the whole set of system can realize chip-level integration.

The invention relates to a high-power dual-wavelength erbium-doped solid laser, and belongs to the technical field of laser. The high-power dual-wavelength erbium-doped solid laser comprises a pumping source, a pumping cavity, a diamond, a heat sink, a first resonant cavity and a second resonant cavity, the first resonant cavity comprises a first erbium-doped YAG slice crystal, and the second resonant cavity comprises a second erbium-doped YAG slice crystal. The first erbium-doped YAG sheet crystal is used for generating 1.64 [mu] m laser which oscillates back and forth in a back-and-forth light path provided by the first resonant cavity; and the second erbium-doped YAG sheet crystal is used for generating 2.94 [mu] m laser which oscillates back and forth in a back-and-forth light path provided by the second resonant cavity. According to the high-power dual-wavelength erbium-doped solid laser provided by the invention, synchronous output of 1.64 mu m and 2.94 mu m dual-wavelength laser is realized, the multifunctionality and medical adaptability of the laser are enhanced, and multi-type treatment requirements of soft tissues and hard tissues can be met at the same time.

The invention discloses a single-stage cavity type power combiner capable of adjusting output power, the single-stage cavity type power combiner is used for an accelerator high-frequency system power source, the single-stage cavity type power combiner adopts a section of coaxial line resonant cavity folded into an n shape as a main body structure of the combiner, and by increasing the number of branches synthesized at a time, the output power of the combiner can be adjusted. The number of the single-stage cavity type power combiner is equivalent to the number of branches of the multi-stage power combiner, so that the multi-stage power combiner is replaced by the single-stage cavity type power combiner; the single-stage cavity type power combiner comprises a plurality of input coupling structures, an output coupling structure and a coaxial line resonant cavity, the plurality of input coupling structures are divided into two groups and are symmetrically distributed at two ends of the coaxial line resonant cavity shaped like a Chinese character'ji ', and each input coupling structure is directly connected with an output port of each power amplifier unit; when the single-stage cavity type power combiner has a module fault, the coupling between the fault module and the system can be quickly relieved, and the output power of other power amplifier modules is adjusted, so that the overall output power is recovered to be balanced.

The invention relates to a single-stage AC-DC converter and a control circuit. The single-stage AC-DC converter comprises a filter, an input rectifier, a filter capacitor Cin, a first switch bridge arm, a second switch bridge arm, a capacitor Cb, an inductor Lb, a resonant cavity formed by a resonant inductor Lr and a resonant capacitor Cr, a transformer T, an output rectifier and an output capacitor Co. According to the invention, a traditional two-stage AC-DC converter and a control circuit are simplified. Compared with a single-stage AC-DC converter in the prior art, the problem that the current of a resonant cavity is too large can be solved only by adding one inductor, meanwhile, the control strategy is simple, the frequency range conversion of a switching tube is small, and soft switching of the switching tube is easy to achieve, so that high efficiency is easy to obtain, input current can be corrected to achieve a high power factor, and the power factor is high. And the output voltage ripple is small, and the method has remarkable engineering application value and market prospect.

The invention provides a passive laser gyroscope based on a light force induced transparency effect and a measurement method thereof, the passive laser gyroscope comprises a frequency stabilized laser light source, a signal modulation input device, a balance homodyne detection device, an annular optical resonant cavity and a signal detection and feedback device, wherein a reflection cavity mirror with a photomechanical resonance structure characteristic is integrated in the annular optical resonant cavity; according to the passive laser gyroscope, a narrow transparent window modulated by a mechanical damping rate is generated on an annular optical resonant cavity of the passive laser gyroscope by utilizing a light force induced transparency effect and a light-mechanical coupling effect, so that the quality factor of the annular optical resonant cavity is improved, and the measurement sensitivity of the passive laser gyroscope is enhanced.

The invention relates to the technical field of sensors, and discloses a decoupling method of a temperature and pressure sensor, and the sensor comprises an F-P resonant cavity and a pressure sensing diaphragm with a fiber bragg grating. The method comprises the following steps: S1, transmitting a wide spectrum signal to a sensor, and collecting a reflection spectrum of the sensor; s2, performing baseline correction and noise reduction processing on the reflection spectrum, and extracting characteristic parameters; s3, if the characteristic parameters exceed the preset range, failure early warning is carried out; establishing and substituting the characteristic parameters into a physical model, performing multi-parameter optimal estimation, and outputting temperature and static pressure; and S4, if the characteristic parameters exceed the preset range, failure early warning is carried out. In order to enable failure early warning to be more accurate, the scheme can be adjusted to monitor the characteristic parameters extracted in the step S2 in real time, and the scheme is not limited to fixed nodes. According to the invention, intrinsic decoupling is realized, the measurement precision, the decoupling efficiency and the intelligent degree are greatly improved, the practicability is high, meanwhile, the self-diagnosis function is realized, and the reliability is ensured.

The invention provides a parameter design method for a multi-voltage rectification LCC converter, and the method comprises the steps: building a voltage precise mathematical model of a resonant cavity parallel capacitor through employing a fundamental wave equivalent method based on the condition that output capacitors of the multi-voltage rectification LCC converter and a multi-voltage rectifier participate in resonance; the gain of the voltage-multiplying LCC resonant converter is modeled through a voltage accurate mathematical model of a resonant cavity shunt capacitor; determining the number of rectifier bridges, the turn ratio of a transformer and the capacitance value of a rectification voltage-multiplying capacitor according to the voltage of the parallel capacitor of the resonant cavity and the gain of the voltage-multiplying LCC resonant converter; and determining values of the resonant cavity series-parallel capacitor and the resonant cavity inductor according to the capacitance value of the rectification voltage-multiplying capacitor. According to the method, analysis and calculation of the output filter capacitance are incorporated into parameter design of accurate modeling, a scheme for selecting the number of the voltage doubling rectifier bridges is given, and the size can be reduced and economic benefits can be increased under the condition that working condition requirements are met.

The invention relates to a leak rate detection device and method based on a laser emission resonant cavity. The leak rate detection device comprises a resonant cavity; a laser transmitter; the conversion device is used for converting the photoacoustic signal into an electric signal; and the processing device converts the electrical signal into a leak rate Q. The leakage rate detection method comprises the following steps: setting an acousto-optic resonant frequency f of the resonant cavity; the wavelength of the laser emitted by the laser emitter is modulated, and the modulation frequency is the same as the acousto-optic resonance frequency f; controlling a laser transmitter to transmit modulated laser to an incidence window, and enabling the laser to irradiate the interior of the resonant cavity after passing through the incidence window; the characteristic gas absorbs the laser to generate vibration, and a photoacoustic signal is generated; collecting a photoacoustic signal by using a conversion device, and converting the photoacoustic signal into an electric signal; modulating the electric signal to obtain the oxygen concentration in the resonant cavity; and obtaining the leakage rate Q of the semiconductor cavity according to the oxygen concentration. According to the invention, the leakage condition of the semiconductor chamber can be accurately detected without shutdown.

The invention relates to the field of building materials, in particular to a novel light sound insulation composite wallboard and a preparation method thereof.The composite wallboard comprises a first layer and a second layer which are compounded in sequence; the first layer is a gradient closed-cell foam layer, and the density of the first layer is distributed in a gradient increasing mode from the first surface away from the second layer to the second surface compounded with the second layer. The second layer is an integrated micro-perforated-adjustable neck depth honeycomb layer and comprises a micro-perforated panel, an adjustable neck depth element and a honeycomb core which are arranged in sequence; the micro-perforated panel is connected with the first layer, the neck depth adjustable element is an elastic film, and the elastic film, the micro-perforated panel and the honeycomb core jointly define a plurality of Helmholtz resonant cavities. According to the light sound insulation composite wallboard, efficient introduction of sound waves is achieved through impedance gradual change design, the adjustable resonance dissipation unit conducts targeted absorption on low-frequency noise, full-frequency-band and high-performance air sound isolation from low frequency to high frequency is achieved, and dual optimization of acoustic performance and space efficiency is achieved.

The invention discloses a non-linear frequency conversion regenerative amplification device and a method thereof, and belongs to the technical field of laser non-linear frequency conversion. The device comprises a signal light injection unit, a regeneration amplification cavity unit and a pump light synchronization unit. The regenerative amplification cavity unit comprises an optical resonant cavity structure module, a polarization control module and a nonlinear action module. A time domain switch is formed through the polarization control module under the driving of the time schedule controller, and the preset number of times of circulation of signal light in the cavity is accurately controlled. And meanwhile, the pump light synchronization unit generates pump pulse string laser which is synchronous with the circulation process and has sub-pulse power increasing in sequence, so that the signal light and one corresponding pump sub-pulse are subjected to optical parametric amplification in the nonlinear crystal in each circulation. The space complexity of multi-stage amplification is converted into time domain controllability, high-efficiency and high-gain nonlinear frequency conversion is realized by using a single-stage compact structure, and the integration level and the stability of the system are remarkably improved.

According to the preparation method of the low-signal-loss copper-clad plate for the AI server, a microwave resonant cavity is integrated between heating plates of a laminating machine, on-line non-intrusive detection on dielectric response of a base material is achieved, the curing degree and stress distribution of resin of each layer are inversed in real time in combination with frequency domain analysis and material dielectric modeling, and the low-signal-loss copper-clad plate for the AI server is obtained. A pre-trained physical information neural network is used to map the three-dimensional pressure-deformation relation; according to the method, model prediction control is adopted to dynamically generate a pressure instruction, closed-loop feedback adjustment and optimization are carried out, technological parameter self-tuning and multi-objective optimization are matched, a knowledge base is established, and strategy autonomous recommendation is realized, so that the flexibility and precision of pressure distribution regulation and control and the consistency of finished products are improved, and continuous iterative optimization of technological experience is supported.

The invention relates to the technical field of microwave semiconductor testing, and discloses a dynamic calibration system for the sensitivity of a microwave photoconductivity tester, which comprises a dual-port orthogonal coupling resonant cavity module provided with a primary port and a secondary port which are orthogonally isolated; the variable capacitance-variable resistance composite modulation perturbation module is connected to the secondary port and is used for generating analog photoelectric response complex impedance disturbance; the vector microwave transceiving and demodulation module is connected to the main port and outputs I / Q signals; the complex impedance track fitting control module is used for driving the perturbation module based on a physical model; the dynamic vector calibration and signal processing module is used for calculating a system transfer function and executing vector projection denoising, the composite modulation perturbation module is used for generating complex impedance disturbance simulating semiconductor photoelectric response at a resonant cavity secondary port, and the vector receiving and transmitting module is combined to obtain a system instantaneous vector transfer function; a system drift error is eliminated by performing de-embedding processing on a measurement signal, and orthogonal noise is eliminated by using a vector projection algorithm.

The invention provides a resonant cavity broadband sound barrier based on a double-helix acoustic black hole. The resonant cavity broadband sound barrier comprises a plurality of double-helix acoustic black hole resonant cavity broadband sound absorption structure cells and a supporting and connecting assembly. The multiple double-spiral acoustic black hole resonant cavity broadband sound absorption structure cells are connected together through the supporting and connecting assemblies, and a plate-shaped sound barrier is formed; the double-spiral acoustic black hole resonant cavity broadband sound absorption structure cell is in the shape of a hollow regular hexagon nut, the inner side face of the cell is open, and six cavities with the inner sides open are formed in the cell. Two spiral curved surface rolling plates with the same or different spiral curve parameters are arranged in each cavity; the curved surface of the spiral curved surface rolling plate is perpendicular to the upper end face and the lower end face of the double-spiral acoustic black hole resonant cavity broadband sound absorption structure cell. A plurality of protruding teeth are distributed on the inner side face and the outer side face of the spiral curved-surface rolling plate. The invention has the advantages that the broadband sound absorption characteristic is realized; certain ventilation and lighting performance is achieved, and the driving environment of an inner channel of the closed traffic sound barrier can be more comfortable.

The invention discloses a gas detection precision improving method based on a multi-algorithm fusion framework. A photonic crystal resonant cavity and a tunable band-pass filtering structure are integrated in a Fourier transform spectrometer light path; collecting a wide-spectrum light intensity signal, and constructing a spectral signal database in combination with the enhancement characteristic and the filtering characteristic of the resonant cavity; zero calibration and dynamic baseline deduction operation are carried out, and self-adaptive variational mode decomposition and wavelet transform are adopted to carry out signal denoising on the spectral signals; an environment compensation model is established, and an Arrhenius type correction factor is adopted to suppress water vapor cross interference; constructing an RLS and fuzzy control combined hybrid adaptive filter; separating aliasing spectral signals by adopting a non-negative matrix factorization algorithm; establishing a quantitative relation model; in the online concentration prediction process, the initial concentration value is subjected to recursive optimization by using a hybrid adaptive filter, the deviation is continuously corrected through an environment compensation model, and an accurate concentration value is output. The method can significantly improve the accuracy and stability of multi-gas detection.

The invention relates to a semiconductor device, e.g. for the emission or absorption of light, preferably in the deep ultraviolet (DUV) range. The device, e.g. a resonant cavity light emitting diode (RCLED) or a laser diode, is formed from: a substrate layer (302), preferably comprising a distributed Bragg reflector (DBR); a graphitic layer (304); and at least one semiconductor structure (310), preferably a wire or a pyramid, grown on the graphitic layer, with or without the use of a mask layer (306). The semiconductor structure is constructed from at least one III-V semiconductor n-type doped region (316) and a hexagonal boron-nitride (hBN) region (312), preferably being p-type doped hBN.

The invention discloses an on-chip fully-integrated optical circulator based on phase modulation. The on-chip fully-integrated optical circulator comprises a substrate, a buried oxide layer, an optical waveguide layer, an upper cladding and a metal layer used for manufacturing metal electrodes, the substrate, the buried oxide layer, the optical waveguide layer, the upper cladding and the metal layer are stacked, the optical waveguide layer comprises two input / output optical waveguide groups, a four-port resonant cavity and two metal electrode pairs, and the metal layer comprises four modulation areas; four ports of the resonant cavity are respectively connected with four interfaces of the modulation area, each input / output optical waveguide group is connected by a bent optical waveguide and coupled to the resonant cavity, the middle of the metal electrode pair is bent to form a coplanar waveguide electrode, and the middle of each two ends of the modulation area is connected by the coplanar waveguide electrode. The fully-integrated optical circulator is realized under the silicon-based substrate for the first time, is compatible with current mainstream optical integration platforms such as SOI, LNOI and LTOI, and can be widely applied to large-scale photonic integrated chips, such as the fields of optical communication, optical sensing, on-chip optical interconnection and the like.

The invention relates to the technical field of lasers, and provides a double-gain-medium Q-switched laser and a constant-power pulse width adjusting method.The laser comprises a first pumping source, a second pumping source, an optical fiber beam combiner, a beam shaping system and a laser resonant cavity, the laser resonant cavity comprises a reflecting mirror, a first gain medium, a second gain medium, a polarization selector, a quarter-wave plate, a Q switch and an output mirror which are arranged in sequence; the first gain medium is used for absorbing first pumping light, the second gain medium is used for absorbing second pumping light, and the pumping power of the first pumping source and the pumping power of the second pumping source can be independently controlled. By changing the pumping power of the two pumping sources, real-time adjustment of the pulse width of the laser under the constant output power is achieved, the structure is compact, and control is easy and convenient.

The invention discloses a high-selectivity waveguide filter based on a nonlinear frequency-variable coupling structure, which comprises three rectangular waveguide resonant cavities, an input waveguide port and an output waveguide port, and the first coupling metal column, the first coupling diaphragm, the first coupling metal block and the first metal baffle plate between the first resonant cavity and the second resonant cavity jointly form a first group of nonlinear frequency change coupling structures. And a second coupling metal column, a second coupling diaphragm, a second coupling metal block and a second metal baffle plate between the second rectangular waveguide resonant cavity and the third rectangular waveguide resonant cavity jointly form a second group of nonlinear frequency change coupling structures. The two groups of nonlinear frequency-variable coupling structures are used for coupling the three rectangular waveguide resonant cavities, and a reflection zero point and two transmission zero points are introduced into each rectangular waveguide resonant cavity, so that the filter response is a five-order Chebyshev response with four transmission zero points. The filter has the advantages of being compact in structure, high in selectivity, good in out-of-band rejection performance, simple in structure, easy to expand and the like, and has a good application prospect.

A frequency multiplier includes an oscillator and a harmonic generator. The oscillator has a resonant cavity and a negative resistance unit. The negative resistance unit includes a feedback capacitor and a parasitic capacitor. The feedback capacitor and the parasitic capacitor collectively provide negative resistance for the resonant cavity. The harmonic generator is configured to generate a harmonic signal based on a fundamental frequency signal taken as input. The oscillator is electrically connected to the harmonic generator, and is configured to receive the harmonic signal, and to output an intrinsic signal with the resonant cavity. A frequency of the intrinsic signal is a multiple of a frequency of the fundamental frequency signal.