41results about How to "Achieve phase lock" patented technology

The invention provides a device for detecting a zero crossing point of inductive current, aiming at the technical problem that the direction of inductive current can not be accurately judged by independently adopting a digital signal processor (DSP) hardware capture module (CAP) and a hysteresis comparison method. The device comprises a current sensor, a partial pressure conditioning module, a voltage following module, a pull-up bias module, a DSP module, an input module and a liquid crystal display (LCD) module. According to the invention, the phase locking function of a single-phase phase-locked loop based on a second-order generalized integrator (SOGI) is adopted, so that the phase locking for the inductive current can be realized, and the zero crossing point and the direction of the inductive current can be further detected. Through the device, the defects that separately using a hardware or software method is adopted are overcome; and equipment is simple, detection is convenient and fast and reliability is high.

The invention relates to a grid-connected phase lock method for an electrified railway power treatment and adjustment device. The method comprises the steps that (1) power grid voltage unbalanced deformation is carried out on the three-phase alternating current component of the power grid voltage; Clark transform is carried out on the deformed power grid voltage; and the power grid voltage is mapped to an alpha beta stationary coordinate system to acquire V alpha beta; (2) the components v alpha and v beta of V alpha beta on alpha and beta axes are shifted by 90 degrees through a second order generalized integrator SOGI module respectively, and the positive-sequence component is calculated; and (3) the extracted positive-sequence component is replaced by the power grid voltage, and the phase lock loop of single synchronization coordinate system software is used to realize the phase lock function of the power grid voltage. Compared with the prior art, the method provided by the invention can effectively filter out harmonic components in the power grid voltage and extract the basic positive sequence component therein to realize successful phase lock.

A strong coupling multi-core optical fiber includes a core area, an internal cladding area and an external cladding area. The optical fiber is characterized in that the core area includes a plurality of large cores and a plurality of sub-wavelength cores arranged in the internal cladding area; the refractive index of the internal cladding area is smaller than that of the large core and the sub-wavelength core but larger than that of the external cladding area; the internal and external cladding areas are both made of solid material with evenly distributed refractive index; the diameter of the large core is in micron dimension, the distance between adjacent large cores is in micron dimension and the diameter of the sub-wavelength core is in hundred micron dimension. The invention has the functions of strong coupling, phase locking, laser shaping and homogenization.

The invention relates to a tool-crashing prevention system of a numerically controlled lathe. The tool-crashing prevention system comprises a tool rest and the lathe on which a workpiece is clamped well. A specular reflection photoelectric switch is arranged in the middle of the tool rest. A roughing tool used for cutting the workpiece is clamped on the tool rest. The cut workpiece is fixed to the lathe through a chuck. The lathe is provided with two reflecting plates in the X-axis direction and the Y-axis direction respectively. The tool rest is moved through a stepped motor. The specular reflection photoelectric switch on the tool rest detects the position of the tool rest through optical signals reflected by the reflecting plates on the X-axis of the lathe and the Y-axis of the lathe. The moving speed and the moving direction of the tool are further judged in the mode that a control system reads the high level or the low level of a pulse signal machine of the numerically controlled lathe, so that whether a tool-crashing accident happens to the tool is judged, and emergency braking is conducted before tool crashing. The tool-crashing prevention system can effectively protect the roughing tool against the tool-crashing accident and has the characteristics of being high in accuracy, reliable in detection, low in cost and the like.

The invention discloses a support platform for installing and disassembling a diesel engine crankshaft vibration reducer. The support platform comprises an axial V-shaped groove for supporting the vibration reducer, a horizontal movable table, and a hydraulic lifting device positioned below the horizontal movable table; a first slide block extends below the axial V-shaped groove; and a first chute matched with the first slide block for use is formed in the horizontal movable table. The support platform for installing and disassembling the diesel engine crankshaft vibration reducer has such advantages as simple structure, convenience for operation, high installation efficiency and good safety, supports and fixes the vibration reducer, enhances the balance of the vibration reducer in the installation process, and prevents the lifting of the vibration reducer; and the transverse motion of the axial V-shaped groove and a lifting mechanism can realize automatic centering of an inner hole of the vibration reducer and the axis of a crankshaft in all directions so as to quickly finish the coaxiality matching of the inner hole of the vibration reducer and the crankshaft.

The invention relates to an external cavity coherent vertical cavity surface emitting semiconductor laser, belongs to the technical field of lasers and solves the technical problem that a coherent laser is complex in structure and poor in reliability in the prior art. The laser comprises a P-type DBR (Distributed Bragg Reflector), an active region, an N-type DBR, a substrate and an N-face electrode which are sequentially and densely arranged from top to bottom. The edge of the upper surface of the P-type DBR is provided with a P-face electrode. The P-type DBR is provided with an oxidation confinement layer with a plurality of oxidation holes. The laser further comprises a high-contrast grating composed of a grating body and an external cavity. The high-contrast grating blocks all light emitting holes and light emitting hole joints. The lower surface of the external cavity is fixed to the upper surface of the P-type DBR, the optical thickness of the external cavity is in integral multiple of half of the wavelength, and the external cavity is made from a dielectric material of low refractive index. The grating body is arranged on the upper surface of the external cavity, the polarization direction is parallel or perpendicular to the (110) crystallographic orientation, the grating body is made from a dielectric material of high refractive index. The external cavity coherent vertical cavity surface emitting semiconductor laser can achieve polarization control and is high in stability and good in reliability.

The invention discloses an optical phase locking method based on microwave photon frequency division. The method comprises the steps of: inputting coupling signals of optical signals output by two monochromatic light sources to be subjected to phase lock into a photoelectric oscillation loop, wherein the oscillation mode of microwave signals with the frequency as shown in the description in the photoelectric oscillation loop is bandpass, and [omega]0 is the difference of the output frequencies of the two monochromatic light sources; forming positive feedback oscillation by the oscillation modeof microwave signals with the frequency as shown in the description in the photoelectric oscillation loop so as to obtain stable micro signals with the frequency as shown in the description; performing phase demodulation for the micro signals with the frequency as shown in the description output by the photoelectric oscillation loop and the local oscillator micro signals, and employing a phase demodulation result after elimination of high-frequency components to perform feedback control for the phase of the at least one monochromatic light source so as to achieve the phase locking of the twomonochromatic light sources. The present invention further discloses an optical phase locking device based on microwave photon frequency division which can overcome the problem of the locking phase jitter and reduce the requirement on phase demodulation so as to achieve high-frequency and stable micro wave signal output.

The invention provides a phase-locked loop system, wherein the phase-locked loop system at least comprises the components of a delay unit which is used for delaying a reference clock signal and a feedback clock signal; and a phase-locked loop component which is connected with the delay unit and is used for outputting a first signal that is locked on the frequency and the phase of the reference clock signal based on the delayed reference clock signal and the feedback clock signal. According to the phase-locked loop system, through overlapping the delay unit into the phase-locked loop component, delaying the reference clock signal and the feedback clock signal, and performing reversal digital compensation on a phase difference between the reference clock signal and the feedback clock signal, inclination of the reference clock signal and the feedback clock signal is eliminated, and the performance of the phase-locked loop component does not reduce. Through adjusting the delay precision of the reference clock signal and the feedback clock signal, fine adjustment for the phase difference under locking of the original locked-phase loop is realized, so that under a precondition that the performance of the phase-locked loop component is ensured, 10ps-20ps magnitude phase locking can be realized.

The invention, which belongs to the technical field of photoelectric detectors, particularly relates to a balanced zero-beat photoelectric detector for non-classical light field detection in a continuous variable quantum optical experiment, in particular to a photoelectric detector for locking a relative phase between a non-classical light field and a local light field and detecting a corresponding phase non-classical light field orthogonal component in a broadband range. The invention aims at providing balanced zero-beat detector having advantages of low noise, high gain and wide bandwidth, thereby solving a problem of detection of specific orthogonal components of a broadband compressed light field and thereby realizing measurement of a specific orthogonal component of compressed light in a broadband range under phase locking of the compressed light and local light. The balanced zero-beat photoelectric detector has advantages of low noise, high gain, wide broadband, alternating-current and direct-current monitoring and phase locking and the like. The balanced zero-beat photoelectric detector can be well used for detecting the orthogonal component of the compressed light after therelative phase between the compressed light and the local light is locked.

The invention discloses a surface-emitting semiconductor laser chip and a preparation method thereof. The semiconductor laser chip is a surface-emitting two-dimensional array light source chip emitting laser from a substrate layer; and the distance between the centers of two adjacent light sources is equal. The chip is sequentially provided with a substrate layer, a front mirror, an active layer,an oxidation optical limiting layer, a rear mirror and an ohmic contact layer from bottom to top; the thickness of the substrate layer, the distance between the surface emitting array light sources and laser wavelength meet a Talpot relational expression; a first electrode is manufactured at the top of the ohmic contact layer; a passivation layer is manufactured at a certain position of the firstelectrode, wherein the position of the first electrode does not contact with the ohmic contact layer; a groove structure is manufactured at the position, corresponding to the oxidation aperture of theoxidation optical limiting layer, of the light-emitting side of the substrate layer, a second electrode is manufactured at the groove position of the substrate layer, and the second electrode and thefirst electrode at the top of the ohmic contact layer are opposite in electrical property; and the non-electrode position of the light-emitting surface of the substrate layer is plated with a semi-reflecting and semi-transmitting film, and laser is emitted at the position.

The invention relates to an optical phase lock-based pulse laser zero-difference coherent detection device and relates to a laser coherent detection device in the technical field of optoelectronics. According to the coherent detection device, after the local oscillator laser and the pulse echo signal laser are input into a 90-degree optical mixer, four paths of coherent optical signals with the phase difference of 0 degree, 90 degrees, 180 degrees and 270 degrees are outputted. Among the four paths of coherent optical signals, two paths of optical signals with the phase difference therebetweento be 0 degree and 180 degrees are outputted through an in-phase branch circuit and then are inputted into a laser phase-locked loop through the 4-photoelectric conversion of a first balance detector. In this way, the phase locking of the pulse signal laser and the continuous local oscillator laser is realized. The other two paths of optical signals with the phase difference therebetween to be 90degree and 270 degrees are outputted through an orthogonal branch circuit, and then pulse laser signals can be completely recovered after the photoelectric conversion of the signals through a secondbalance detector. According to the pulse spectrum width of the pulse signal laser, a corresponding narrow-band detector is selected for receiving signals. Therefore, high-sensitivity detection signalscan be obtained.

The invention discloses a high-power external cavity semiconductor laser device. An outer cavity VCSEL array surface light source is composed of a plurality of VCSEL array light sources, wherein a P-type epitaxial layer of each VCSEL array light source is a multi-film total reflection P-type epitaxial layer, an N-type epitaxial layer of each VCSEL array light source is a multi-film partial reflection N-type epitaxial layer, reflectivity of each N-type epitaxial layer is 50-90%, the outer cavity VCSEL array surface light source is installed on a concave surface of a concave surface reflector, agroove is formed in the middle of a 45-degree oblique angle cylindrical reflector, and a convex surface outer cavity reflector is installed in the groove and right faces the outer cavity VCSEL arraysurface light source. The laser device is advantaged in that a coupling resonant cavity is formed by a concave reflector, the multi-film total reflection P-type epitaxial layer, the multi-film partialreflection N-type epitaxial layer and the convex outer cavity reflector, loss of different transmission modes is controlled by utilizing the feedback adjustment effect of the coupling resonant cavityof the light beam, a high-order mode is suppressed, so phase locking between array units is realized, and the light beam quality of an output light beam is improved.

The invention provides a semiconductor laser coherent array, and the array is characterized in that the semiconductor laser coherent array comprises a multi-mode interference region which comprises amulti-stage one-to-two multi-mode interference coupling structure and a plurality of bent waveguides, wherein the multi-mode interference coupling structure between different stages is connected through the bent waveguides, and the multi-stage one-to-two multimode interference coupling structure is used for generating a plurality of phase coherent optical branches; a reflection region which is used for transmitting the plurality of optical branches and controlling the energy ratio output by the optical branches by adjusting the reflectivity; and an array region which comprises a plurality of channel waveguides and is used for carrying out power amplification on the plurality of optical branches output by the reflection region and then outputting the amplified optical branches. The invention further provides a preparation method of the semiconductor laser coherent array.

The invention discloses a phase-locked amplification method and system in TDLAS gas detection. The method comprises the following steps of acquiring the amplitude and frequency of a modulation current corresponding to a gas to be detected; obtaining a phase angle of a frequency multiplication component in a gas absorption spectrum signal It, wherein the phase angle eta of the frequency multiplication component is a signal deviation phase angle; setting a parameter and taking the parameter as a phase of a k frequency multiplication reference signal; repeatedly adjusting until the k-order harmonic wave is close to an ideal harmonic wave waveform; and obtaining a value when the k-order harmonic wave is close to the ideal harmonic wave waveform, and assigning the value to the phase angle of a double component and the obtained eta to realize phase locking. According to the invention, the problem caused by phase-locked amplification in the gas detection by using a hardware phase-locked loop in the prior art is solved, so that the hardware cost is reduced, and the gas detection precision is improved to a certain extent.

The invention provides an optical comb control method and system based on an electric control polarization controller. The system comprises a laser light source used for providing seed light, an amplifying device used for amplifying the energy of the seed light, a self-reference beat frequency detection device used for detecting and obtaining a repetition frequency signal and a carrier envelope phase signal, and a phase locking device used for locking the repetition frequency signal and the carrier envelope phase signal. The polarization state of the seed light in the optical fiber is controlled by applying a driving voltage through the electric control polarizer and the module, and nonlinear polarization rotation of the seed light is realized; locking of the carrier envelope phase signalis realized by controlling the polarization state of the seed light in the resonant cavity; phase locking of repetition frequency signals is achieved by controlling the length of the resonant cavity.

An all-fiberized double-path ring laser comprises two ring lasers with the same structure. Each ring laser is characterized in that two ends of a section of rare earth ion doped fiber are respectively connected with an output end of a pumping beam combiner and a second port of a 2*2 fiber beam splitter, and a third port of the 2*2 fiber beam splitter is connected with a second input end of the pumping beam combiner through a fiber so as to form each ring laser. An output end of a pumping source is connected with a first input end of each pumping beam combiner. Fourth ports of the two 2*2 fiber beam splitters of the ring lasers are connected through a fiber. First ports of the two 2*2 fiber beam splitters serve as laser output ends. The all-fiberized double-path ring laser is small in size, stable in structure, free of the requirements for isolators and fiber gratings, low in cost and capable of achieving self-stabilization of an output laser mode and phase locking of the two paths of the lasers without the requirements for active control.

The invention relates to the technical field of rotating part surface deformation and pressure distribution measurement, in particular to a rotating part surface deformation and pressure distribution synchronous measurement system. The system comprises a laser light source module, an image acquisition module, a synchronous control module and a rotating part carrier, the laser light source module is a laser light source capable of outputting 10ns pulse width; the image acquisition module comprises two cross-frame CCD (Charge Coupled Device) cameras, and the two cross-frame CCD cameras are used for acquiring two images within a set time interval; the synchronous control module is used for providing a trigger signal of the laser light source module and an acquisition signal of the image acquisition module; the rotating part carrier comprises a rotating part to be measured, and the surface of the rotating part to be measured is provided with PSP coating and speckle mark points. The system effectively controls motion blur of the rotating part, so that an image is clear and visible; and phase locking of the high-speed rotating component is realized.

The present invention provides a phase-locked loop system, wherein the phase-locked loop system at least includes: a delay unit for delaying a reference clock signal and a feedback clock signal; a phase-locked loop component connected to the delay unit for The delayed reference clock signal and the feedback clock signal output a first signal locked to the frequency and phase of the reference clock signal. The present invention superimposes the delay unit into the phase-locked loop component, and by delaying the reference clock signal and the feedback clock signal, reverse digitally compensates the phase difference between the reference clock signal and the feedback clock signal to eliminate the reference clock signal and the feedback clock signal The skew will not affect the performance of the phase-locked loop components themselves; by adjusting the delay accuracy of the reference clock signal and the feedback clock signal, to achieve fine adjustment of the phase difference locked by the original phase-locked loop, so that in On the premise of ensuring the performance of the phase-locked loop components, phase locking in the order of 10 ps to 20 ps can be realized.

A strong coupling multi-core optical fiber includes a core area, an internal cladding area and an external cladding area. The optical fiber is characterized in that the core area includes a plurality of large cores and a plurality of sub-wavelength cores arranged in the internal cladding area; the refractive index of the internal cladding area is smaller than that of the large core and the sub-wavelength core but larger than that of the external cladding area; the internal and external cladding areas are both made of solid material with evenly distributed refractive index; the diameter of the large core is in micron dimension, the distance between adjacent large cores is in micron dimension and the diameter of the sub-wavelength core is in hundred micron dimension. The invention has the functions of strong coupling, phase locking, laser shaping and homogenization.

The invention relates to a three-phase locking and frequency conversion integrated machine with dual grid-connected switches and a phase locking method. The integrated machine comprises a main loop and a control loop, wherein the main loop comprises a frequency converter, four vacuum contactors, two voltage Hall sensors and a motor, and the control loop comprises four intermediate relays, a PLC and a control switch. When a system works, the starting process and phase locking of an output voltage on a grid power voltage are completed by the frequency converter, on / off control on the vacuum contactors is completed by the PLC through controlling the action of the intermediate relay, so that the functions of power supplied to a motor from the frequency converter during starting and power supplied to the motor from a power grid after phase locking and switching of the vacuum contactors are completed in a steady state are achieved. A three-phase locking technology is used for performing phase locking on the power grid voltage, a power grid phase and an output voltage phase of the frequency converter are locked by a PI controller, and the consistency of the voltage phases during the switching process of a power supply is ensured.

Using mechanism of inner wastage in laser cavity implements self-adjustment of phase, and combining active control implements phase lock obtained even under outputting high power. Meanwhile, synthesized laser output in single beam is obtained directly. The disclosed equipment includes at least two resonant cavities to constitute Vernier-Michelson resonant cavity, or Mach-Zehnder resonant cavity, or Fox-Smith resonant cavity. Detector detects outputted light intensity split by beam splitter. Using feedback to control phase variation realizes coherent synthesis of laser. Advantages are: high efficiency, compact structure, single beam of laser output in large power, and stable system performance.

Double grid-connected switch three-phase phase-locked frequency conversion integrated machine and phase-locked method. The integrated machine is composed of a main circuit and a control circuit. The main circuit is composed of a frequency converter, four vacuum contactors, two voltage Hall sensors and a motor. The circuit is composed of four intermediate relays, PLC and control switch; when the system is working, the frequency converter completes the start-up process and the phase-locking of its output voltage to the grid voltage, and the PLC completes the switch control of the vacuum contact by controlling the action of the intermediate relay , so as to realize the power supply to the motor by the frequency converter at start-up, and the function of power supply to the motor by the power grid after the switching of the phase-locked and vacuum contactors is completed in the steady state; the present invention adopts three-phase phase-locked technology to phase-lock the voltage of the power grid, and adopts PI control The inverter locks the phase of the power grid and the output voltage phase of the inverter; it ensures that the voltage phases of the two are consistent when the power switching process occurs.

The invention discloses an interferometer. The interferometer comprises a base, a light propagation portion which is formed on the base and comprises a first light propagation path and a second lightpropagation path, a phase locking module which is formed on the base, is connected with a fourth reflector of the first light propagation path and is used for adjusting the position of the fourth reflector to make phase difference of a first sub light beam and a second sub light beam not greater than 0.06 rad and make light path difference of the first light propagation path and the second light propagation path not greater than 6nm. Compared with an interferometer in the prior art, the interferometer is advantaged in that the active phase locking purpose can be realized, ultrafast two-dimensional electronic spectrum experiment demands can be satisfied, and accuracy of the experiment result can be improved.

The invention discloses an infrared laser coherent combination device and method, comprising an output mirror and a laser, the rear surface of the laser and the output mirror are end mirrors that are mutually injected into a phase-locked cavity, and all the lasers are arranged in a symmetrical ring around the center; It is used to realize the energy mutual injection of asymmetric two-way lasers; the polarizer is used to ensure the polarization direction of the laser output laser, and is used to realize the energy mutual injection of two symmetrical lasers; the half-wave plate is used to rotate the polarization direction of the laser, and The polarizers are used together to change the mutual injection energy; the rotating parabolic mirror has axisymmetric and central symmetric, and the reflector is placed at the focal point of the rotating parabolic mirror; the reflector reflects the laser light reflected by the rotating parabolic mirror to its centrally symmetrical position. The invention has the characteristics of simple structure and easy realization, no need for active phase detection and correction, good expandability, high synthesis efficiency, etc., making coherent synthesis of more channels and higher power mid-infrared quantum cascade lasers possible.

The invention relates to a fiber laser four-wave mixing drive to generate a wide-band tunable far-infrared comb device. The femtosecond pulse laser is sequentially sent from the phase modulation amplifier and the pulse main amplifier, and obtains non-linear characteristics including different wave bands. The far-infrared optical comb modulates the nonlinear characteristic peaks of different bands to obtain a far-infrared optical comb containing two or more frequencies that transmits collinearly, and then splits the optical comb by means of spectrum separation. , to obtain two or more space-separated far-infrared combs. The phases of the seed laser comb and any Stokes laser comb are exactly the same, so the seed laser comb and the Stokes laser comb can be regarded as two combs with naturally correlated phases, which can be realized without additional modulation Phase locked. During the generation of the far-infrared comb, the detection feedback signal is respectively fed back to the femtosecond laser seed source part and the pulse width modulation part, thereby stabilizing the time jitter and phase noise of the far-infrared comb.

The invention provides a multi-machine cooperative positioning precision optimization method and system. The method comprises the steps: setting a plurality of airborne nodes, generating a TDOA matrixthrough employing the nodes, obtaining a positioning hyperbolic equation according to the matrix, solving the positioning hyperbolic equation, and obtaining a target position coordinate value; carrying out system carrier-to-noise ratio valuing to obtain a pseudo code synchronization error in the ranging system, setting a time delay fluctuation level of a device in a working bandwidth, obtaining asystem time delay error, and calculating the ranging error of the system according to the pseudo code synchronization error and the system time delay error. By using a phase-locked loop module and adopting a phase-locked mode combining coarse search and precise search, achieving phase locking and calculating a phase error; and estimating a target position range according to the target position coordinate value, the system ranging error and the phase error. In this way, the positioning precision is optimized from multiple dimensions of distance and phase.

The invention relates to a full-digital-frequency tracking inverting type electromagnetic induction heating power supply. The traditional simulation phase-locked ring based on a chip CD4046 has the defects that the frequency tracking frame is narrower, the dynamic response is slower, the reliability is poor and the dead-area time is realized by needing an auxiliary circuit and the like. The power supply comprises a substrate (1). The substrate is provided with a voltage feedback unit circuit (2) and a current feedback unit circuit (3); the voltage feedback unit circuit is connected with a central processing unit circuit (5) by an analog-to-digital converter (ADC) (4); the current feedback unit circuit is connected with the central processing unit circuit by phase locking (6); the central processing unit circuit is respectively connected at an online testing JTAG (joint test action group) interface unit circuit (7), a reset circuit (8), an oscillating OSC (open source commerce) unit circuit (9), a frequency tracking circuit (21) and a power supply unit circuit (11); and the frequency tracking circuit is connected with an isolation driving unit circuit (20) through a buffer driving unit circuit (10). The full-digital-frequency tracking inverting type electromagnetic induction heating power supply is used for material melting of the plastic industry.