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164results about How to "Achieve tuning" patented technology

Optical parameter chirp impulse amplification laser system

A optical parameter chirp pulse amplification laser system, includes a titanium gem femtosecond mode-locking pulse oscillator, a first splitting film, a CEP steady signal pulse source, an OPCPA synchronous pumping source, an OPCPA amplifier stage and compressor. In the output beam direction of the titanium gem femtosecond mode-locking pulse oscillator is the first splitting film, which divides a laser beam into a transmission light beam and a reflection light beam, and in the said transmission light beam is said CEP steady signal pulse source, OPCPA amplifier stage and compressor in order. The said CEP steady signal pulse source comprises a photonic crystal optical fiber, a chirp mirror, a period polarization lithium niobate crystal and a stretcher; said OPCPA amplifier stage comprises a first two-tone mirror, a first nonlinear crystal, a second two-tone mirror and a second nonlinear crystal; said OPCPA synchronous pumping source comprises a Q-tuning frequency-multiplier YAG laser, a narrowband titanium gem regenerating amplifier and a second splitting film, and a holophote. The invention apparatus may get a near-infrared ultrashort laser pulse output with a pulse width less than 30 femtoseconds.
Owner:SHANGHAI INST OF OPTICS & FINE MECHANICS CHINESE ACAD OF SCI

Magnetic control tunable optical fiber comb filter

The invention relates to a magnetic control tunable optical fiber comb filter belonging to the technical fields of optical fiber sensing and optical fiber communication. The magnetic control tunable optical fiber comb filter comprises a broadband light source, an optical fiber coupler, an optical fiber environment, a magnetic field generating unit and a photoelectric detector, wherein the optical fiber environment comprises a left arm optical fiber, a right arm optical fiber and a PCFG (Photonic Crystal Fiber Grating). The magnetic control tunable optical fiber comb filter is characterized in that the PCFG cladding is provided with five large shaddock-form air holes of single-layer structures, and magnetofluid is filled into the large air holes through a capillary phenomenon and changes in the refraction index under the action of a variable magnetic field to change the effective refraction index of a PCFG cladding and cause the wavelength movement of a harmonic peak coupled between a PCFG base mode and a cladding mode so as to realize the tunability as the output characteristics of the filter. Because of different lengths of the left arm optical fiber and the right arm optical fiber in the optical fiber environment, two paths of light signals reflected by the PCFG have a light path difference and are subjected to interferences when returning to the optical fiber coupler so that a comb filter effect is generated in an output spectrum of the filter.
Owner:NORTHEASTERN UNIV

Package structure and package method of integrated tunable antenna array and radio frequency module

The invention discloses a package structure and package method of an integrated tunable antenna array and a radio frequency module. The package structure comprises a rigid-flexible board and a radio frequency module package body, wherein the rigid-flexible board is used for arranging an antenna array patch, the radio frequency module package body is used for packaging a radio frequency chip, the rigid-flexible board and the radio frequency module package body are vertically and oppositely arranged and are fastened by four bolts and nuts, the four bolts and nuts are arranged at corners and arematched, and the rigid-flexible board is fixedly connected with one side of the radio frequency module package body by a second flexible substrate. With the package structure of the integrated tunableantenna array and the radio frequency module, fabricated by the invention, the integration of the integrated tunable antenna array and the radio frequency module is achieved, moreover, the tuning ofthe antenna array also can be achieved, the package structure has the characteristics of high integration, good electromagnetic shielding effect, antenna gain, high radiation efficiency, small radiation power and low loss, and the demands of different application occasions can be satisfied.
Owner:NAT CENT FOR ADVANCED PACKAGING

Microminiature optical add/drop filter based on two-dimensional photonic crystal

The invention belongs to an optical add / drop filter, and particular relates to a microminiature optical add / drop filter based on a two-dimensional photonic crystal. The invention is characterized in that the optical add / drop filter comprises an upper end direct waveguide, a lower end direct waveguide and an autocollimating ring zone; the electromagnetic field energy of the upper end direct waveguide and the lower end direct waveguide are coupled to further form a resonant cavity by a photonic crystal ring zone; the range of the frequency or wavelength of photonic crystal autocollimating work is covered by an upper end waveguide working zone. The upper end direct waveguide and the lower end direct waveguide consist of dielectric column type photonic crystal arrays which are arranged by tetragonal lattices with line defects, and also consist of a photonic crystal arrays which are arranged by triangular lattices with line defects or two-dimensional plates with line defects. The photonic crystal autocollimating ring zone forms a photonic crystal autocollimating microring by adjusting the size of the radius of the photonic crystal of the ring zone under the limitation of an external photonic crystal band gap. The microminiature optical add / drop filter has more compact structure and simpler design and is applicable to optical communication and optical sensing system.
Owner:FUJIAN NORMAL UNIV

Distributed Bragg reflector (DBR)-based external cavity wavelength-tunable laser

The invention discloses a distributed Bragg reflector (DBR)-based external cavity wavelength-tunable laser, which comprises an active photonic chip. An optical waveguide is arranged in the photonic chip, and comprises a gain section and a reflection grating section. The two sides of each section are provided with a corresponding electrode respectively. An optical lens, an optical etalon and a reflector are sequentially arranged on one side an optical waveguide port from which the emitted light of a reflection grating is derived, and form a passive external cavity feedback area which forms a laser resonant cavity with the photonic chip. Photons obtain maximum feedback at an overlapped wavelength by changing the comb maximum reflection peak distribution of the reflection grating section or simultaneously changing the comb maximum reflection peak distribution and the maximum transmission peak distribution of the optical etalon to realize the stepped or continuous tuning of output laser wavelengths and changing the output laser wavelengths within a relatively wider range.
Owner:李若林 +1

Method for generating down link structure and frequency-tunable millimeter wave of millimeter wave optical fiber transmission system

The invention relates to the down-link structure of a millimeter-wave fibre-optic transmission system and a method for generating millimeter waves with tunable frequencies. In the down-link structure of the millimeter-wave fibre-optic transmission system, double lasing light emitters are arranged in a key station, a first light wave passes through a double electrode Mach-Zehnder modulator, and a light carrier which carries digital baseband signals and comb spectral components which are spaced by the frequency of radio-frequency signals are generated at the output end of the modulator. A second light wave which passes through a circulator is taken as pump light and is injected into a polarization-preserving fiber in a reverse direction, the frequency of the second light wave is changed so as to amplify the comb spectral components of corresponding frequency points in the first light wave through stimulated Brillouin effect, and millimeter-wave signals with the corresponding frequencies can be generated at a photodetector on a base station. As the millimeter-wave signals are modulated by the digital baseband signals, the down transmission of information needed from the key station to the base station is realized. The RoF down-link has simple structure and realizes the purpose of simultaneously transmitting the digital baseband signals and the radio-frequency signals by utilizing one double electrode Mach-Zehnder photomodulator.
Owner:SHANGHAI UNIV

Method for narrowing line width of semiconductor laser by means of improved phase modulation heterodyning technology based on electric feedback

The invention discloses a method for narrowing the line width of a semiconductor laser by means of an improved phase modulation heterodyning technology based on electric feedback. The method for narrowing the line width comprises the steps: an output signal of the laser is connected to a frequency shifting MZ interferometer through an acoustic optical modulator, the frequency noise of the laser is converted into phase noise, coherent demodulation is carried out by a radio-frequency signal with controllable frequency deviation, then, frequency correction signals are obtained through amplification and filtering, a part of the frequency correction signals enter a driving current of the laser, the other part of the frequency correction signals are connected to an electric input end of the acoustic optical modulator behind a photoelectric detector, the frequency of the laser is corrected, the phase noise is reduced, and therefore the aim of narrowing the line width is achieved. The method for narrowing the line width has the advantages that the device is simple and easy to achieve, and a high-fineness FP cavity is not required; the line width is narrowed, and the frequency can be modulated at the same time; a high-quality light source is provided for a coherent light communication and high-resolution spectrograph; the requirements for the frequency of the laser do not exist, and therefore narrowing of the line width of the laser in various wavebands can be achieved.
Owner:TIANJIN UNIVERSITY OF TECHNOLOGY

Reconfigurable microwave receiver front-end based on micro-electro-mechanical microwave power sensor

The invention discloses a reconfigurable microwave receiver front-end based on a micro-electro-mechanical microwave power sensor, wherein the self detection function of an online-type MEMS (Micro Electro Mechanical System) microwave power sensor is adopted to convert microwave power, which is partially coupled by an MEMS membrane bridge, into direct current level, the direct current level applies online control to a preprocessor capable of attenuation and amplification so that the output of the front-end keeps stable when an MEMS microwave antenna receives too large or too small microwave signals, and simultaneously, the effect of protecting a low noise amplifier to prevent the low noise amplifier from overloading is achieved when the MEMS microwave antenna receives super large microwave signals suddenly; furthermore, a single microwave receiver front-end can work within a plurality of frequency bands through the MEMS microwave antenna and an MEMS adjustable wave filter, thereby the way that the traditional single microwave receiver front-end achieves the above function by a relatively complex AGC (Automatic Gain Control) module is replaced and the defect of single operating mode is overcome; and the front-end based on the MEMS technology has the characteristics of lower loss and small volume, etc.
Owner:SOUTHEAST UNIV

Intelligent excitation control system for generator set

The invention relates to an intelligent excitation control system for a generator set. The system includes a voltage detection unit, a data processing unit, a PID calculation unit, a power amplification unit and an intelligent instruction list, wherein the intelligent instruction list is used for determining PID parameters of the PID calculation unit and stores a plurality of sets of instructions, and each set of instruction consists of a preset voltage deviation value, a preset voltage deviation change rate and corresponding PID parameters; and an intelligent control unit is used for receiving information of a voltage deviation value e and a voltage deviation change rate ec, and judging whether difference value rates of the voltage deviation value e and the voltage deviation change rate ec and the preset voltage deviation value and the preset voltage deviation change rate in the intelligent instruction list are lower than preset different value rates, if yes, the PID parameters in the instruction are input to the PID calculation unit, and if no, an instruction with the sum of the abovementioned two difference value rates being minimum is selected, and the PID parameters in the instruction are input to the PID calculation unit. The system has a relatively good excitation control effect.
Owner:SHANDONG WANYA POWER SCI & TECH CO LTD

Vernier effect based tunable microfiber laser and production method thereof

ActiveCN103682962AImprove finenessFree spectral range Large tuning rangeActive medium shape and constructionSpectrum analyzerResonance
The invention discloses a vernier effect based tunable microfiber laser and a production method thereof. The laser comprises a semiconductor pump laser (1), an active microfiber cascade resonance structure (3) and a spectrum analyzer (5). Pump laser light emitted from the semiconductor pump laser (1) is coupled into the active microfiber cascade resonance structure (3) through a first micro-nanofiber (2), and laser light generated by the active microfiber cascade resonance structure (3) is coupled through a second micro-nanofiber (2) to enter the spectrum analyzer (5). The microfiber laser has tenability, can monitor changes of external environment parameters (such as temperature and refractive index strain), and has the advantages of small size, compact structure, flexible design and the like, thereby being capable of meeting application requirements in different fields of curing material monitoring, environmental pollution monitoring such as gas and soil, biomedical detection and the like.
Owner:HUAZHONG UNIV OF SCI & TECH

Band-shaped beam klystron outer tuning apparatus

The invention provides a band-shaped beam klystron outer tuning apparatus. The apparatus comprises an accommodation cavity, a tuning assembly, a trapezoid lever bracket and a control assembly. An inductance tuning mode is adopted, and a tuning piston is inserted into a band-shaped beam klystron tube body to form a cavity wall of a resonant cavity; and the motion of the tuning piston is controlled through a lever principle so as to change the size and distribution inductance of the resonant cavity and further change the resonant frequency of the resonant cavity. According to the invention, a flexible seal membrane sheet rather than a corrugated pipe is adopted for realizing tuning of the resonant cavity so that the cost is reduced, and the structure is simplified.
Owner:INST OF ELECTRONICS CHINESE ACAD OF SCI

Semiconductor laser-pumped kerr lens mode-locked titanium sapphire laser

The invention discloses a semiconductor laser-pumped kerr lens mode-locked titanium sapphire laser, which comprises first semiconductor lasers, a resonant cavity, an interferometer and a feedback regulation unit, wherein the first semiconductor lasers are used for emitting continuous laser light of blue and green bands to pump titanium sapphire crystal in the resonant cavity; the resonant cavity is used for carrying out oscillating and mode locking on the laser light of near-infrared bands to output femtosecond pulse laser light; the interferometer is used for driving the femtosecond pulse laser light to generate a beat note signal to obtain a carrier-envelope offset frequency; and the feedback regulation unit is used for regulating front and back positions and gradients of end mirrors ofthe resonant cavity and the power of the laser light output by the semiconductor lasers, thereby keeping the stability of a repetition frequency and the carrier-envelope offset frequency. An ultrashort laser light pulse with stable repetition frequency and carrier-envelope offset frequency can be output, and the semiconductor lasers are directly adopted as pumping sources, so that the cost of thelasers is greatly reduced, and the volume of the whole lasers is further reduced.
Owner:HUAZHONG UNIV OF SCI & TECH

Terahertz metamaterial waver absorber with proactively tunable frequency and manufacturing method thereof

The invention discloses a terahertz metamaterial waver absorber with a proactively tunable frequency and a manufacturing method thereof. The wave absorber comprises a bottom structure, an intermediatedielectric layer and a top resonant structure. The bottom structure includes at least one metal film. The intermediate dielectric layer is fixed to the bottom structure. The top resonant structure isfixed to the intermediate dielectric layer, and includes a plurality of metal resonant structures arranged in an array. The plurality of metal resonant structures are fixed to the same end surface ofthe intermediate dielectric layer away from the bottom structure. A resonant cavity is disposed in each of the metal resonant structures. Each resonant cavity and the corresponding metal resonant structure are in a cross shape and have a coincident center. Both the metal film and the metal resonant structures are made of copper. The intermediate dielectric layer is made of a flexible PDMS material. Each resonant cavity is filled with a SrTiO3 material. The waver absorber realizes control of incident electromagnetic waves, tunes the wave absorbing frequency of the metamaterial in a large range, and overcomes the limitation of the passive tuning method of the wave absorbing property of the metamaterial.
Owner:INNER MONGOLIA UNIVERSITY

High-order dispersion compensation and chirp spectrum widening system

ActiveCN107024816AEfficient and high-quality optical parameter conversionEfficient and high-quality laser outputNon-linear opticsUltra-widebandEngineering
The invention provides a high-order dispersion compensation and chirp spectrum widening system. The high-order dispersion compensation and chirp spectrum widening system comprises an impulse oscillator, an optical fiber pre-amplifier, an optical fiber main amplifier and a high-order dispersion compensation and spectrum stretcher, wherein the high-order dispersion compensation and spectrum stretcher is used for performing high-order dispersion compensation and spectrum expansion on pulse which is output by the optical fiber main amplifier and amplified for the second time, and femtosecond laser pulse is obtained. The high-order dispersion compensation and spectrum stretcher comprises a first collimating lens, a half-wave plate, a first reflector, a first diffraction grating, a first diffraction prism, a second diffraction prism, a second diffraction grating, a prism square, a second reflector, a high-power space isolator, a coupling lens, a photonic crystal fiber and a second collimating lens which are arranged in an optical path sequence. With adoption of the high-order dispersion compensation and chirp spectrum widening system, high-efficiency and high-quality optical parametric conversion and ultra-wideband femtosecond pulse laser output can be realized.
Owner:UNIV OF SHANGHAI FOR SCI & TECH

Device and method for tuning echo wall micro-cavities

InactiveCN106226971AAchieve tuningSmall quality factor effectNon-linear opticsFiberElectricity
The invention provides a device and a method for tuning echo wall micro-cavities. The device comprises an optical fiber. The echo wall micro-cavities which are positioned on a side of a fiber core are arranged in cladding of the optical fiber, graphene is laid at cavity openings of the echo wall micro-cavities and is connected with electrodes, and voltages are applied to the graphene by the electrodes, so that the echo wall micro-cavities can be tuned. The device and the method have the advantages that the echo wall micro-cavities are integrated in the optical fiber, the fiber core in the optical fiber is used as waveguide for exciting the echo wall micro-cavities, and accordingly the device is compact and stable in structure; distances between the echo wall micro-cavities and the waveguide for exciting the echo wall micro-cavities rarely change in tuning procedures, accordingly, the device and the method rarely affect quality factors of the echo wall micro-cavities, and the tuning accuracy of the echo wall micro-cavities can be improved; only input laser devices are required in the tuning procedures, extra laser devices can be omitted, and accordingly the device and the method are low in tuning cost; the graphene is extremely high in heat conductivity, heat generated by the graphene can be quickly transmitted to the echo wall micro-cavities, and accordingly the device and the method are high in tuning efficiency.
Owner:CHONGQING UNIV

Frequency stabilization and light intensity stabilization dual-piezoelectric ceramic tuning external cavity semiconductor laser

The invention discloses a frequency stabilization and light intensity stabilization dual-piezoelectric ceramic tuning external cavity semiconductor laser. The laser comprises a laser diode module, a collimator, a light intensity stabilizing module, a blazed grating, an output reflector, an output polarization light splitting module, a two-dimensional adjusting module, a flexible adjusting platform, piezoelectric ceramic a, piezoelectric ceramic b, a frequency stabilizing module, a bottom plate, an elastic damper and a shell. The double piezoelectric ceramics are adopted to drive the flexible adjusting platform to achieve blazed grating rotation and translation, the length of the outer cavity can be adjusted when the angle of the grating is adjusted, a fixed longitudinal mode is kept in theouter cavity, and therefore broadband mode-hopping-free tuning is achieved. When atomic absorption spectrum characteristic analysis needs to be carried out, a frequency tuning mode can be adopted, and when a stable laser beam is needed, a light intensity stabilizing mode and a frequency stabilizing mode can be adopted; the output reflector and the blazed grating are placed on the flexible adjusting platform together, and the output light beam does not deflect in the tuning process.
Owner:GENERAL ENG RES INST CHINA ACAD OF ENG PHYSICS

Broadband active inductor with high Q values and coarsely tunable and finely tunable inductance value

The invention discloses a broadband active inductor with high Q values and a coarsely tunable and finely tunable inductance value. The broadband active inductor comprises a first transconductance unit (1), a modulation unit (2), a second transconductance unit (3), a third transconductance unit (4), a fourth transconductance unit (5), a first tunable bias circuit (6), a second tunable bias circuit (7), a third tunable bias circuit (8) and a fourth tunable bias circuit (9). The modulation unit is connected with the first transconductance unit and is used for increasing the Q values and bandwidth of the active inductor. The first transconductance unit, the modulation unit and the second transconductance unit form a master circuit. The third transconductance unit and the fourth transconductance unit form a slave circuit. The master circuit and the slave circuit are connected in parallel. The equivalent capacitance for synthesizing the inductance in the whole circuit is increased, so the inductance value of the active inductor is improved. According to the active inductor, the high Q peaks of the active inductor under different frequencies are realized, the Q peaks can be tuned, and the inductance value of the active inductor is coarsely tuned and finely tuned.
Owner:BEIJING UNIV OF TECH

Electromagnetic wave absorber based on refractory material

The invention discloses an electromagnetic wave absorber based on a refractory material. The electromagnetic wave absorber comprises a protective film layer, a dielectric film layer and a particle structure layer, wherein the protective film layer is arranged on the lower surface of the dielectric film layer, the particle structure layer is arranged on the upper surface of the dielectric film layer, the protective film layer is made of the refractory material, and the particle structure layer is composed of arrays in which particles of the refractory material are periodically arranged. By means of the electromagnetic wave absorber based on the refractory material, by introducing the refractory material and using the material characteristics of the refractory material itself, the material then forms electromagnetic resonance with incident electromagnetic waves, and high electromagnetic waves are formed to be absorbed; through the three-layer structure system of the protection layer, thedielectric film layer and the particle structure layer, electromagnetic resonance characteristics of the refractory material at the ultraviolet-visible-near-infrared bands are applied, and the spectral absorption of the broadband is achieved.
Owner:JIANGXI NORMAL UNIV

Incubation room temperature control method based on cat group optimization and immune fuzzy PID

The invention discloses an incubation room temperature control method based on cat group optimization and immune fuzzy PID, the temperature of an incubation room serves as a controlled object, a temperature physical model of the incubation room is established through a transfer function, a control rule table, a fuzzy theory domain, a fuzzy language value and a subordinating degree function of a fuzzy ID controller algorithm are designed to realize setting of an integral coefficient and a differential coefficient; a fuzzy reasoning is used for approximating the inhibition amount of cells in animmune algorithm, an immune control rule is determined, an immune control rule, a fuzzy theory domain, a fuzzy language value and a subordinating degree function of an immune P controller algorithm are designed to realize setting of a proportion coefficient; a cat group optimization algorithm is used for intelligent optimization of values of a quantification factor a scale factor of the immune P controller algorithm to determine optimal values of the quantization factor and the scale factor; the temperature of the incubation room can be accurately controlled, the incubation room temperature control method has good dynamic and static performance, is small in overshoot, and fast in adjusting time, and the self-setting of PID parameters is realized quickly and efficiently.
Owner:汇佳网(天津)科技有限公司

Grey cosine distribution optical target simulation device for MTF (modulation transfer function) detection

The invention relates to a grey cosine distribution optical target simulation device for MTF (modulation transfer function) detection and belongs to the technical field of image quality assessment of an optical system. The device comprises a lighting source, a narrow band filter, a flat field microobjective, a pinhole reticle, a first optical alignment system, a polarization beam splitter, a variable optical density board, a first standard plane mirror, a second standard plane mirror, a beam splitter, a calibration camera, a coupling objective, a second optical alignment system, a high-precision displacement adjustment table and a controller. The grey cosine distribution optical target simulation device for modulation transfer function detection can accurately simulate a grey cosine distribution target with the space frequency and modulation degree matched with those of a to-be-detected optical system, the grey cosine distribution target is input for MTF detection of the to-be-detected optical system, which accords with the original definition of MTF, besides, MTF of the to-be-detected optical system can be directly measured, follow-up data processing is not required, and accordingly, the precision and the efficiency of MTF detection are improved.
Owner:CHANGCHUN INST OF OPTICS FINE MECHANICS & PHYSICS CHINESE ACAD OF SCI

Space mapping algorithm-based automatic computer-aid tuning design method for microwave device

The invention discloses a space mapping algorithm-based automatic computer-aid tuning design method for a microwave device, which can accurately and efficiently automatic tune the microwave device. The method comprises the following steps of: calling an electromagnetic simulation program to establish an electromagnetic model of the microwave device, calling a circuit simulation program to establish a circuit model of the microwave device, regarding an electromagnetic model parameter set as an accurate space, regarding a circuit model parameter set as a rough space, analyzing the mapping relationship of the two spaces by a space mapping algorithm, mapping the known optimal parameter set of the rough space into the parameter set of the accurate space, adjusting the space mapping relationship by verifying the accuracy of the parameter set of the accurate space, and finally acquiring the optimal parameter set of the accurate space by multiple times of adjustment. Human-machine function expansion is performed based on implementation of a core algorithm so as to implement a series of automatic behaviors such as model update, data update, log operation and the like. The method can well improve the time and labor-wasting tuning of the microwave device, and can be used for unattended auxiliary automatic tuning microwave devices.
Owner:NANKAI UNIV

Multi-wavelength optical fiber filter

The invention discloses a multi-wavelength optical fiber filter, comprising a first single mode optical fiber, a second single mode optical fiber, a photonic crystal optical fiber and a temperature control module; one end of the first single mode optical fiber is connected with one end of the photonic crystal optical fiber for inputting light beams; one end of the second single mode optical fiber is connected with the other end of the photonic crystal optical fiber for outputting the light beams; the temperature control module is attached to the side wall of the photonic crystal optical fiber for regulating and controlling the temperature of the photonic crystal optical fiber and realizing the tuning on the multi-wavelength optical fiber filter in the free-spectrum range; an organic matter layer for enhancing the thermal sensitive property of the photonic crystal optical fiber is filled in air holes of the photonic crystal optical fiber. The multi-wavelength optical fiber filer has the characteristics of flexible and adjustable free spectrum range and flat top of transmitted spectrum.
Owner:HUAZHONG UNIV OF SCI & TECH

Surface-enhanced optical spectrum underlay of unsymmetrical double-split ring

InactiveCN101672785ALarge electromagnetic field enhancement effectImprove stabilityIndividual molecule manipulationRaman scatteringSplit ringResonance
The invention concretely discloses a surface-enhanced optical spectrum underlay of an unsymmetrical double-split ring, belonging to the technical field of surface optical spectrum. The underlay consists of a substrate and unsymmetrical double-split ring structural units which are periodically arranged on the substrate to form a two-dimensional array on the substrate. The unsymmetrical double-splitring structural unit is a metal split ring formed by two metal arcs with different lengths. The underlay of the invention has simple structure, large electromagnetic enhanced effect, good stability and reproducibility. Two strong extinction peaks in a near infrared region and an optical frequency, respectively correspond to a first-order resonance (I) and a second-order resonance (II); the electric filed enhanced effect can be further improved by reducing the width of the slit and optimizing a top structure; the wavelength range of the first phase resonance (I) and the second phase resonance(II) can be adjusted through structure parameters, so that the wavelength range of the surface-enhanced optical spectrum application can be satisfied.
Owner:ZHENGZHOU UNIV

High-stability multi-wavelength fiber laser with adjustable wavelength interval

The invention discloses a high-stability multi-wavelength optical fiber laser with adjustable wavelength intervals, and belongs to the field of optical fiber communication and instruments and meters.According to the laser, a polarization controller II (09), a polarization maintaining optical fiber I (10), a polarization controller III (11) and a polarization maintaining optical fiber II (12) aresequentially connected between an interface 081 and an interface 082 of an optical fiber coupler I (08) to form a double-order Sagnac filter. A pump (01),a wavelength division multiplexer (02), an erbium-doped optical fiber (03), a first optical fiber coupler (04), a high-nonlinearity optical fiber (05), a first polarization controller (06) and a second optical fiber coupler (07) jointly form an NALM-NOLM structure, mode competition is inhibited, and the laser output stability is greatly improved. The wavelength interval can be changed by adjusting two polarization controllers in the filter. The laser has the advantages of simple structure, flexible output wavelength and the like, and is suitable for a wavelength division multiplexing system.
Owner:BEIJING JIAOTONG UNIV

Four-wave mixing based continuously trap wave tunable microwave photonic filter

The invention discloses a four-wave mixing based continuously trap wave tunable microwave photonic notch filter. Multi-wavelength laser is generated by four-waving mixing to serve as a light source of the microwave photonic filter to realize a multi-tapping effect. Sidebands and phases of photoelectric current generated after phase modulation control by a waveshaper form trap waves, and phase shift magnitude is introduced additionally to form a complex coefficient to realize continuous tuning of the trap waves. Passband center frequency of output radio-frequency signals of the microwave photonic filter has characteristics of tunable band-reject filter waves, and tunability in trap wave center frequency of the filter is realized according to the phase shift magnitude introduced to optical carriers and modulating signals by the waveshaper. The microwave photonic notch filter has advantages of simple structure, developed operation techniques and low cost, solves problems of small tuning range and failure in continuous tunability of existing phase modulation based microwave photonic notch filters and is applicable to fields of national defense, industrial production and civilian use.
Owner:TIANJIN UNIVERSITY OF TECHNOLOGY

Tunable laser with double output light beams

ActiveCN103762487AFast Fine TuningFast Precision Fine TuningOptical resonator shape and constructionSemiconductor lasersLight beamGain
The invention relates to a tunable laser with double output light beams. The first structure of the laser comprises a first laser cavity reflector, a laser gain medium, an intra-cavity collimating lens, an active optical phase modulator, a tunable acoustic-optic filter, a tunable Fabry-Perot filter, a second laser cavity reflector and a laser device controlling and driving system. A zero-level light beam which enters the tunable acoustic-optic filter after being reflected by the first laser cavity reflector forms the first laser output light beam and a zero-level light beam which enters the tunable acoustic-optic filter after being reflected by the second laser cavity reflector forms the second laser output light beam. According to the second structure of the laser, a Fabry-Perot etalon is added in the first structure, so that the purpose of further compressing the laser output frequency bandwidth is achieved. The tunable laser with the double output light beams has the advantages of being reasonable in design, free of mechanical movable part, stable and reliable in performance, low in cost, small in size, easy to install and produce and the like.
Owner:GP PHOTONICS INC

Multi-wavelength external cavity laser for non-fluorescence raman spectrometer

The invention discloses a multi-wavelength external cavity laser for a non-fluorescence raman spectrometer. More than two laser diodes with equal central wavelengths in an array are driven to be independently opened and closed through a power supply switching circuit; output light beams are calibrated into parallel collimated laser beams through a collimating laser calibration optical element; a special design is adopted by a grating; different grating periods are set for incident point regions, corresponding to the collimated laser beams, of the grating; the collimated laser beams form zero-order reflected beams and first-order diffracted beams after being diffracted by the grating; the zero-order reflected beams are output in the same direction and have a wavelength difference; the first-order diffracted beams return to the inside of the corresponding laser diodes along the original path to participate in internal mode competition of a resonant cavity; and the zero-order reflected beams are converged into an optical fiber combiner through an optical fiber coupling lens for wavelength output. The wavelength output is switched by the circuit, so that the unreliability and the possible error of conventional mechanical adjustment are eliminated; a tuning structure is relatively simple and stable; high stability of output wavelengths is ensured; the wavelength output repeatability in actual operation is high; and the tuning accuracy is relatively high.
Owner:SUZHOU UNIV

Method for obtaining high-repetition-frequency large-energy tunable laser

The invention provides a method for obtaining high-repetition-frequency large-energy tunable laser, relates to the field of tunable laser, and aims at the solving the problem that consideration is not given to both high repetition frequency output and large energy output of the tunable laser in the present tunable laser technology. Time domain modulation is carried out on high-repetition-frequency pumped pulse laser to output pumped pulse train laser; and the output pumped pulse train laser is shaped by a light beam shaping system, input to a first reflection prism, reflected by the first reflection prism and then input to a dye box, a dye solution in the dye box is excited by the pumped pulse laser, the laser is further input to a resonant cavity composed of an output coupling mirror, a grating and a tuning mirror, a light beam expander is inserted into the resonant cavity to prevent laser in the cavity from damaging the grating, the tuning mirror is rotated, and pumped pulse laser output by the output coupling mirror is reflected by a second reflection prism and a third reflection prism to realize laser wavelength tuning. The method can be used to modulate the high-repetition-frequency pumped pulse laser.
Owner:HARBIN INST OF TECH

Broadband microwave photon phase coded signal generation device and method

InactiveCN111565075AOvercome high frequencyOvercoming the Electronic Bottleneck Problem of Large BandwidthPhotonic quantum communicationRadar systemsSoftware engineering
The invention provides a broadband microwave photon phase coded signal generation device and method. An output port of a laser is connected with an input port of a carrier modulation module, an outputport of the carrier modulation module is connected with an input port of a phase encoding modulation module, an output port of the phase encoding modulation module is connected with an optical inputport of a photoelectric detector after passing through the optical fiber, and the photoelectric detector outputs a required phase encoding signal. According to the invention, an integrated polarization multiplexing modulator is used to generate an optical carrier signal, and then the polarization modulator is used to carry out phase coding modulation on the generated carrier signal so as to generate a phase coding signal without baseband interference. The amplitude of the signal is tuned by controlling the DC bias voltage of the polarization multiplexing modulator, so the system provided by the invention is expanded to a phased array radar system and a frequency-controlled array radar system, has a wider application scene, and is of great significance to the fusion and development of next-generation military and civil radar systems.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

Reconstructible high-frequency chirped pulse signal generating device and method

InactiveCN106199534AAchieve tuningChange dispersion characteristics in real timeWave based measurement systemsGratingFrequency spectrum
The invention relates to a reconstructible high-frequency chirped pulse signal generating device and method, and mainly aims at solving the problems that high-frequency chirped pulses generated in a present method cannot satisfy high frequency and high-precision range finding requirements for a modern radar. A femto second pulse signal generated by a femto second laser (1) is input to a fiber loop including a linear chirp fiber Bragg grating (7) and an adjustable delay line (6) via a three-port circulator a (2) for spectrum shaping, the optical pulse signal after spectrum shaping is input to a reconstructible chirp Bragg grating (9) via a three-end circulator b (3) for frequency-time mapping, an optical high-frequency chirped pulse signal, and a photoelectric detector (4) converts the optical high-frequency chirped pulse signal into an electrical high-frequency chirped pulse signal. Reconstructible frequency-time mapping is realized, the reconstructible high-frequency chirped pulse signal is realized, and the requirement of high bandwidth can be satisfied at the same time.
Owner:HARBIN INST OF TECH
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