454 results about "Laser modulation" patented technology

Optical fiber switches operated by electrical activation of at least one laser light modulator through which laser light is directed into at least one polarizer are used for the sequential transport of laser light from a single laser into a plurality of optical fibers. In one embodiment of the invention, laser light from a single excitation laser is sequentially transported to a plurality of optical fibers which in turn transport the laser light to separate individual remotely located laser fuel ignitors.The invention can be operated electro-optically with no need for any mechanical or moving parts, or, alternatively, can be operated electro-mechanically. The invention can be used to switch either pulsed or continuous wave laser light.

The invention provides a laser imaging radar device and a distance measurement method thereof. The laser imaging radar device and the distance measurement method thereof aims at the problem that an existing distance range gate laser imaging radar is low in distance resolution. The laser imaging radar device comprises a laser device, a laser modulation unit, an optical antenna unit, a detecting unit, a data processing unit and an image processing unit, wherein the detecting unit is composed of a counter, a gate controller and an array detector, and the data processing unit is composed of an accumulator and a correlator. According to the distance measurement method, an information loading process is carried out on laser signals with constant amplitude by using a phase code pulse amplitude modulation mode. The laser imaging radar device and the distance measurement method thereof have the advantages that the equipment and the method combine the advantages of long detecting distances of the distance ranging gate layer imaging radar and the advantage of high distance measurement resolution of the pulse phase coding mode, and meanwhile the detect of low distance measurement resolution of the distance ranging gate layer imaging radar and the detect of low imaging speed of the pulse phase coding mode are avoided.

A color image forming apparatus produces a latent image on a photosensitive body based on a signal output from a scanning light detecting part in response to detection of scanning light; a semiconductor laser modulation signal generating part includes a clock generating part and a clock modulation part; a semiconductor laser and a semiconductor laser driving part are provided for each color of yellow, magenta, cyan and black; and further, a plurality of the semiconductor lasers are provided for at least one color of yellow, magenta, cyan and black.

A Q-switched semiconductor laser is supposed to facilitate high-frequency laser modulation with low currents or voltage ranges. According to the invention, a laser of this type consists of at least one continually pumped active medium and two optically coupled resonators at least one of which is passive, both resonators having different mode combs corresponding to the Nonius principle, at least one resonator mirror taking the form of a reflector with strongly dispersive reflection characteristics in the laser wavelength range selected by the double resonator, the index of refraction of the passive resonator and/or reflector capable of being adjusted electronically. With this device, the reflectivity of the laser wavelength can be adjusted in such a way that, with a fixed effective amplification by electrical modulation of the reflectivity of the resonator reflector with strongly dispersive reflection characteristics, the laser threshold can be raised or lowered so as to switch the semiconductor laser on or off.

A modulated laser light detector that converts laser light energy into electrical signals which exhibit a frequency that is substantially the same as the laser light modulation frequency, in which these signals allow the detector unit to determine a position where the laser light is impacting upon a photodiode array. A synchronous rectifier circuit is provided which, by use of a phase locked loop, converts a full-wave analog signal representative of the modulated laser energy into a half-wave analog signal, which is filtered and demodulated to generate a DC level that is indicative of the strength of the received laser light energy. At least two channels of these signals are used to determine the impacting position of the laser light energy.

The invention discloses a method for controlling brittleness Laves phases in the laser additive manufacturing process of a nickel-based high-temperature alloy. Firstly, laser additive manufacturing technological parameters are initially optimized, and a cooling medium is adopted for cooling the bottom of a base material; then a laser modulation technology is used for modulating a laser source, and superior laser modulation parameters are obtained, wherein the peak power of square waves ranges from 600 W to 1000 W, the pulse frequency of the square waves ranges from 10 HZ to 100 HZ, and the duty ratio of the square waves ranges from 0.3 to 0.6; the wave peak power of sawtooth waves ranges from 600 W to 1200 W, the wave trough power of the sawtooth waves is 0 W, and the pulse frequency of the sawtooth waves ranges from 10 HZ to 100 HZ; and according to the parameters of sine waves, the wave peak power ranges from 600 W to 1000 W, the wave trough is 0 W, and the pulse frequency ranges from 10 HZ to 100 HZ; and finally, laser additive manufacturing and forming of the nickel-based high-temperature alloy are conducted according to the above parameters, and a formed part with all small equiaxial dendritic structures and small discrete Laves phases is obtained. By means of the laser modulation method, the precipitation behavior of the Laves phases in the laser additive manufacturing process of the nickel-based high-temperature alloy can be effectively controlled, the cracking sensibility of parts obtained through laser additive manufacturing is reduced, and the microstructure is improved.

The invention discloses an X-ray pulsar navigation embedded simulation system based on a semiconductor laser, which comprises a data simulation unit, a photon emission unit, a photon detection unit and a navigation test unit. The data simulation unit simulates X-ray pulsar radiation signal data, and sends the X-ray pulsar radiation signal data to the photon emission unit; the photon emission unit uses simulation data to modulate light intensity of a laser modulation laser, and radiate lasers to the atmosphere; the photon detection unit receives the lasers of the photon emission unit from the atmosphere, filters non-laser spectra components in background sunlight, and sends the received lasers to the navigation test unit after carrying out counting on the received lasers; and the navigation test unit carries out noise elimination, pulse profile accumulation, pulse arrival time measurement treatment on the data of the photon detection unit, and utilizes time measurement data to carry out a navigation test. The invention can provide a complete simulation experiment platform for obtaining navigation signals, signal processing, time synchronization and navigation design verification of navigation signals.

The invention discloses a structural material for the modulation of terahertz waves, which belongs to the technical field of electronics. The structural material comprises a medium substrate (2) and a vibratron array (1) attached to the surface of the medium substrate (2), wherein the medium substrate (2) is the medium material substrate highly transparent to the terahertz waves; the vibratron array (1) consists of a plurality of vibratron units with the same shape and size; and each vibratron unit is formed by a vanadium dioxide thin film on deposited on the surface of the medium substrate (2). The structural material adopts a medium material highly transparent to the terahertz waves as the substrate to achieve little and stable terahertz wave absorption loss, adopts the vanadium dioxide thin film which is a high-speed phase change material to manufacture the vibratron array, realizes the modulation of the terahertz waves by triggering the phase change of the vanadium dioxide thin film by thermal or laser modulation, and compared with a conventional metal vibratron array-based terahertz modulator, has greater modulation depth.

The invention discloses a multi-pulse star signal simulator comprising a numerical value simulation unit, a first frequency integration unit, a laser modulation unit, a laser emission unit, a detectorunit, a second frequency integration unit and a photon counting logical unit, wherein the numerical value simulation unit generates radiation signal data of a plurality of pulse stars by using a clock of the first frequency integration unit according to a signal numerical value model and sends the radiation signal data to the laser modulation unit; the laser modulation unit generates a current signal which can directly modulate a laser according to the clock of the first frequency integration unit; the laser emission unit converts the current signal of a laser modulator into a laser intensitysignal; the detector unit receives the laser signal, generates pulses and sends the pulses into the photon counting logical unit; and the photon counting logical unit counts the pulses according to aclock of the second frequency integration unit and sends a counting result to an upper computer. The invention has the advantages of high data reliability and coincidence of a signal generation and detection mechanism with the actual condition and is used for providing simulated data to the independent celestial navigation simulation of a spacecraft.

The invention discloses a DMD-based dual-mode optical super-resolution microscopic imaging device and method. The device comprises multiple lasers of different wavelengths, a laser modulation module and a microscope optical imaging system. The laser modulation module comprises a DMD pattern generation module and a mask plate. The DMD pattern generation module is matched with the mask plate to gate different diffraction light spots so that the objective of realizing two types of super-resolution microscopic technology imaging of SIM and SMLM by sharing the same optical path can be achieved. The DMD has the response speed and the stability higher than those of a mechanical shutter and can be used for wavelength separation so that the cost is lower and use is easier in comparison with the acousto-optic tunable filter, the optical path system is enabled to be more compact and the cost of the system can be greatly reduced. Implementation of different imaging modes depends on multiplexing of the DMD. Using the DMD is put forward for the first time, and two technologies of SIM and SMLM are realized in the same optical path so that advantage complementation of the two super-resolution imaging technology of SIM and SMLM is facilitated, and the device and the method can be used for the research of multiple cell biological problems.

A cavity enhanced absorption spectrometer (CEAS) and method for controlling the same. The CEAS includes a coherent electro-magnetic radiation source, an electro-magnetic modulator that creates a sideband with an adjustable frequency that is offset from the radiation source frequency by imparting an adjustable frequency modulation to the radiation. The CEAS also includes a RF source that drives the electro-magnetic modulator and a cavity enhanced absorption resonator (CEAR) that receives the sideband. A detector measures the proximity of the frequency of the sideband relative to the resonant frequency of the CEAR and generates a proximity detector signal, which is converted by a controller to a control signal that controls at least one of the RF source and the resonant frequency of the CEAR such that the frequency of the sideband and the resonant frequency of the CEAR are adjusted to maintain a predetermined proximity therebetween.

The invention discloses a rotating table type femtosecond laser direct writing device. The rotating table type femtosecond laser direct writing device comprises a femtosecond laser source, a laser path, an X-Y axis two-dimension translation table, a rotating table and a controller, wherein the laser path is provided with a laser modulator, a two-dimension laser scanning galvanometer and a microobjective, after being modulated by the laser modulator, laser beams from the femtosecond laser source pass through the two-dimension laser scanning galvanometer to be projected onto a machined workpiece through the microobjective; the rotating table is arranged on the X-Y axis two-dimension translation table, a rotating shaft of the rotating table is aligned with a direct writing light axis, the table face of the rotating table is perpendicular to the direct writing light axis, and the machined workpiece is fixed onto the table face of the rotating table, and the controller is constructed into a form capable of controlling the laser beams incoming onto the machined workpiece through the laser path and the operation of the X-Y axis two-dimension translation table and the rotating table.

Various embodiments of the present invention relate to a laser driver, and more particularly, to systems, devices and methods of applying low current pulses to a laser modulation current to reduce the speckling noise on the projected images.

The invention discloses a continuous laser frequency modulation range measurement device based on a resampled signal splicing method. The device comprises a tunable laser, a laser controller, a self-adaptive measurement interference system, an auxiliary interference system, a synchronous data collection system, a data processing system and a temperature control system. The tunable laser provides linear frequency modulation laser light, the auxiliary interference system generates clock signals used for resampling, the self-adaptive measurement interference system adjusts the length of reference optical fibers according to the actual distance of a measured object, the synchronous data collection system synchronously samples two paths of beat frequency signals generated by the self-adaptive measurement interference system and the auxiliary interference system, the data processing system conducts resampling and signal splicing, and a distance measurement result is obtained through calculation. Due to the fact that the measurement resolution ratio is limited by laser modulation linearity and the modulation range, the data processing method can be used for compensating for the laser modulation linearity, broadening the equivalent modulation range and improving the distance measurement resolution ratio. The continuous laser frequency modulation range measurement device is suitable for the field of high-precision laser distance measurement.

A modulated laser light detector that converts laser light energy into electrical signals which exhibit a frequency that is substantially the same as the laser light modulation frequency, in which these signals allow the detector unit to determine a position where the laser light is impacting upon a photodiode array. A superheterodyne receiver circuit is used to provide high gain at an improved signal-to-noise ratio to improve the range at which the modulated laser light signal can be reliably detected. Various types of signal detection circuits are available. Various processing algorithms are disclosed, including one which rejects laser light strikes that are due to reflections, rather than due to a direct strike from the laser transmitter.

A high-accuracy distance measurement device of laser consists of microcontroller, storage expansion module, communication interface module, power supply module, laser modulation-driving module, laser emitter, driving module of laser start-up signal, laser-receiving power supply module, laser receiving module, filtering amplifier, high-accuracy time interval measurer and output module.

The invention belongs to the field of optical measurement, relating to a multi-channel single photon counting measuring system based on digital lock phase de-multiplex. The system comprises a light source part, a measuring part, a digital-to-analogue conversion circuit, a digital circuit, a communication circuit and a computer, wherein the digital circuit outputs a digital sine to obtain a simulative sine wave through the digital-to-analogue conversion circuit, a laser modulator modulates the amplitude of a laser and couples a plurality of beams of modulated lasers with different frequencies into one beam to form into a light source of frequency division multiplexing, the light source irradiates an object to be measured, an emitted weak diffused light is captured by a single photon counting measurer, and an electric pulse is outputted through a circuit; and the digital lock phase arithmetic which is tightly combined with the single photon counting is realized by the digital circuit, and a mixed signal from different light resources is extracted in a separating way in a passageway of the measurer according to a preset parameter when receiving the electric pulse to obtain the intensity information of an emergent light which corresponds to each light source. The system shortens the measuring time, reduces the complexity thereof, improves the flexibility of the circuit, and reduces the measuring error.

Improved dispersion compensating circuits for optical transmission systems are disclosed. According to the improved method, there is provided a compensation circuit comprising a varactor diode network. The network is preferably inserted between a source of laser modulating signal and the laser. A low-pass filter or all pass filter constructs the network. The network preferably includes an inductor or inductors and a combined circuit, which includes varactors. The network preferably provides an amplitude dependent delay of the modulating signal applied to the laser or to the optical receiver as post dispersion correction circuitry. In a first embodiment, a fixed capacitor is in series with a varactor and connected to a DC bias through inductor. Additional embodiments, using multiple varactors in different circuit configurations, with particular advantages for various applications identified.

This invention comprises a converged printer architecture for controlling both electro-photographic (EP) processing and raster image processing (RIP) of data for laser modulation over a video line. By converging EP process control with image processing control, significant advantages in cost, image quality, and output stability are achieved. A digital signal processor (DSP) serves as the central processing resource of the architecture. The DSP is well suited for the dual role of image processing and real-time feedback process control. The DSP can operate in open loop motor/motion control, print process control, and in closed loop feedback control including image processing adaptations for quality and stability enhancements.