114results about How to "Modulation speed" patented technology

A method for producing a high frequency optical signal component representative of a high frequency electrical input signal component, includes the following steps: providing a semiconductor transistor structure that includes a base region of a first semiconductor type between semiconductor emitter and collector regions of a second semiconductor type; providing, in the base region, at least one region exhibiting quantum size effects; providing emitter, base, and collector electrodes respectively coupled with the emitter, base, and collector regions; applying electrical signals, including the high frequency electrical signal component, with respect to the emitter, base, and collector electrodes to produce output spontaneous light emission from the base region, aided by the quantum size region, the output spontaneous light emission including the high frequency optical signal component representative of the high frequency electrical signal component; providing an optical cavity for the light emission in the region between the base and emitter electrodes; and scaling the lateral dimensions of the optical cavity to control the speed of light emission response to the high frequency electrical signal component.

The invention discloses a bandwidth adjustable liquid crystal terahertz wave plate based on a porous graphene transparent electrode. Sub-wavelength metal wire gratings are arranged on the inner side of a substrate of an incidence surface, porous graphene is arranged on the inner side of a substrate on an exit surface, and the two substrates made of fused quartz are sealed and combined to form a liquid crystal box. Two light-control orientation layers are sandwiched between the metal wire gratings and the porous graphene in the liquid crystal box, liquid crystal materials are sandwiched between the two light-control orientation layers, and the liquid crystal materials are terahertz electronic control large birefringence liquid crystal materials. Parallel orientation of liquid crystals is achieved in the liquid crystal box through the mode of light-control orientation, and a 45-degree included angle is formed between the orientation direction and the direction of the metal wire gratings. According to the bandwidth adjustable liquid crystal terahertz wave plate based on the porous graphene transparent electrode, the electronic control birefringence characteristic of the liquid crystals is used, phase delay of ordinary light and extraordinary light is regulated through voltage to correspond to specific wave plates with different frequencies, and the bandwidth adjustable liquid crystal terahertz wave plate has the advantages of being superwide in frequency band, capable of achieving automatic polarization, high in transmittance, large in modulation amount, rapid in response and the like and can be widely applied in the booming terahertz field.

The invention relates to an elliptic partial measurement device and a measurement method based on a spatial light modulator, which are applied to observation measurement on the thickness of a sample surface nano-scale thin film. The elliptic partial measurement device has the characteristics that the phase delay of polarization in the two vertical directions of a light beam is changed by adopting the spatial light modulator, an elliptic partial image of the sample surface thin film is recorded by adopting an area array detector, data is processed by adopting a fitting algorithm and an iterative algorithm, and the shape parameter of the sample surface thin film is accurately measured. The elliptic partial measurement device has the beneficial effects that no rotating part exists, the system instability and the azimuth angle deviation are eliminated, the elliptic partial measurement device is not sensitive to temperature, and the defects of a polarizer rotating type and photo-elastic modulation type ellipsometer are effectively overcome.

The invention discloses an electro-optic modulator based on a Si-VO2 composite waveguide. The modulator comprises a silicon substrate, a SiO2 lower cladding, a ridge waveguide, a SiO2 upper cladding, and a metal electrode layer. The ridge waveguide is carved with a slot. A protruding strip is filled with VO2 to form the Si-VO2 composite waveguide. A flat board on two sides is filled with SiO2 for insulation. A P-type lightly doped region and an N-type lightly doped region on two sides of the slot form a PN junction. Metal electrodes are connected with heavily doped regions on two sides of the flat board. The modulator uses phase changes of ViO2 under the force of electric field to induce changes of refraction rate so as to achieve modulation. The modulator is simple in structure, high in modulation extinction ratio, and low in insertion loss. Meanwhile, the inclined ViO2 slot structure is utilized to increase the length of effect and reduce the intensity of reflected light. The modulator has wide application prospect in the field of optical communication and integrated optoelectronics.

The invention discloses an electro-optic modulator based on a micro-ring Mach-Zehnder interferometer structure. The electro-optic modulator comprises an incident waveguide, a bending waveguide, the Mach-Zehnder interferometer structure and a traveling wave electrode, the incident waveguide is a straight waveguide and used for receiving incident light and outputting emergent light, a short distance is formed between the bending waveguide and the incident waveguide, the incident light passing through the incident waveguide is coupled into the bending waveguide, the emergent light passing through the bending waveguide is coupled into the incident waveguide and outputted, an input end of the Mach-Zehnder interferometer structure is connected with an input end of the bending waveguide, an output end of the Mach-Zehnder interferometer structure is connected with an output end of the bending waveguide to form a micro-ring resonant cavity, the Mach-Zehnder interferometer structure is used for increasing light loss of the micro-ring resonant cavity, and the traveling wave electrode is used for loading voltage to the Mach-Zehnder interferometer structure, so that the Mach-Zehnder interferometer structure is used for modulating the intensity of light inputted into the structure. The MZI (Mach-Zehnder interferometer) structure is added into a micro-ring uncoupled area, and the incident light is modulated by switching over a micro-ring critical coupling state and a noncritical coupling state.

The modulator is composed of substrate, control circuit, low electrodes layer, simply supported beam, movable reflector and fixed glass plate. Being formed on the substrate, low electrodes layer is contacted to control ends of each electrode in control circuit. The simply supported beam and support anchor are formed on the insulating layer, which is deposited on the low electrodes layer. Array of movable reflector is supported by the support anchor. The said array and the low electrodes layer constitutes parallel plate condenser with variable gap. There is certain gap between the fixed glass plate and the movable reflector. Shape of aircraft wing is adopted in the beam in order to reduce topographic effect and increase flatness of surface of movable reflector. Vertical up/down motion of the movable reflector happens under action of electrostatic force. Thus, the modulator modulates phase of light to realize switching state. Features are: quick response and simple structure.

The invention discloses a broadband-adjustable terahertz wave plate component which comprises two quartz substrates, metal wire gratings are arranged inside the quartz substrates, the metal wire gratings on two sides are parallel to each other, and the two quartz substrates form a liquid crystal box through frame glue. The liquid crystal box comprises an optical control orientation layer and a liquid crystal material. Liquid crystal is an electric control large birefringence liquid material. The optical control orientation layer and the liquid crystal material of the liquid crystal box achieve parallel orientation of the liquid crystal through an optical control orientation method, the orientation direction of the optical control orientation layer and the direction of the metal wire gratings form a 45-degree angle, and the liquid crystal box can achieve an adjustable one quarter or a half wave plate in a terahertz frequency range. The broadband-adjustable terahertz wave plate has the advantages of being wide in frequency range, self-polarization, high in transmittance, large in modulation quantity, fast in response and the like. In addition, the manufacture cost is low, efficiency is high, the broadband-adjustable terahertz wave plate can be produced in massive mode, and the application prospects are wide.

The invention discloses a linear frequency modulation single frequency pulse optical fiber laser device. The laser device comprises a narrow linewidth seed source, a radio-frequency signal source, an electro-optic modulator driver, a double-parallel phase modulator, an optical fiber beam splitter, an acoustic-optic modulator driver, an acoustic-optic modulator and an optical fiber amplifier. According to the laser device, broadband linear frequency modulation is conducted through the 2*2 MZI structure double-parallel phase modulator, pulse chopping is conducted through the acoustic-optic modulator, and high peak value power output is achieved through the optical fiber amplifier. The laser device has the advantages of being high in peak value power, large in modulation bandwidth, high in modulation speed, high in modulation linearity, simple in structure, capable of achieving the all-fiber laser, safe to human eyes, capable of achieving linear polarization output and capable of satisfying the application requirements of a remote high resolution distance measurement and velocity measurement laser radar for the laser source and can be applied to such fields as remote coherent distance measurement, synthetic aperture/retro-synthetic aperture laser radars and space situation awareness.

The invention relates to the field of optical fiber sensing, in particular to an emergent light spot strength homogenizing mode-disturbing device for a large-bore-diameter multimode optical fiber. After laser output by a laser sequentially undergoes aperture diaphragm filtration, light spot size of the laser beam and divergence angle of the laser beam are adjusted through a beam expander, incident angles of light of different modes in the laser beam are adjusted through an optical fiber mode-disturbing device, the polarization state of the laser beam is adjusted through a polarizer, the laser is coupled through a lens group and an optical attenuator to enter the optical fiber, and light output through the optical fiber is received by an image sensor. Spatial isolation between independently designed optical fiber mode-disturbing components and the mode-disturbing device and the optical fiber is achieved, the mode-disturbing device is applied to different optical transmission systems conveniently, and damage to the optical fiber is avoided simultaneously. The emergent light spot strength homogenizing mode-disturbing device has the advantages of being quick in modulation speed, high in adjusting performance, good in flexibility, easy to maintain and adjust, economic and practical.

This invention discloses a Q-modulated semiconductor laser with an electric absorption structure including a distributed feed-back grating of lambda/4 phase shift, two separated upper electrodes depositing on the top of the grating, an electrode depositing on the base of the laser as the public base, in which, the first upper electrode covers part of the grating including a phase shift region providing gain to the laser by injecting constant current, a second upper electrode covers the rest part of the grating away from the phase shift region as the Q-modulator of the laser and electric signals can be added to the second upper electrode to change the absorption coefficient of the waveguide of the modulator region and alter the Q value of the laser so as to alter the laser threshold value and output power.

The invention discloses a terahertz wave modulating device with light control flat panel silicon photonic crystal and a method thereof. The terahertz wave modulating device comprises a silicon chip, air holes, a modulated semiconductor laser, a terahertz wave source, an input end of a linear defect area, an output end of the linear defect area, and the linear defect area; the middle of the silicon chip is provided with the linear defect area; the silicon chip on two sides of the linear defect area is provided with the air holes; the silicon chip, the air holes and the linear defect area form the flat panel silicon photonic crystal; the modulated semiconductor laser is arranged above the linear defect area; and terahertz waves emitted by the terahertz wave source are input from the input end of the linear defect area, pass through the linear defect area, and are output from the output end of the linear defect area. The edge of a forbidden band of the flat panel silicon photonic crystal modulates the terahertz waves to realize load signals onto the terahertz waves. The terahertz wave modulating device has the advantages of low transmission loss, large modulation bandwidth, quick modulation speed, high extinction ratio, small size, compact structure, and convenient integration, and meets the communication requirement of the terahertz waves.

The invention relates to a driving module and driving method of a laser radar and a semiconductor laser. The driving module comprises an energy storage capacitor, a charging inductor, a one-way conduction element and an adjusting switch tube. The energy storage capacitor is used for providing instantaneous large current for the semiconductor laser, and the semiconductor laser responds to the instantaneous large current to emit laser pulses. The charging inductor is electrically connected with the charging power supply and used for charging the energy storage capacitor. The unidirectional conduction element is arranged between the energy storage capacitor and the charging inductor and is electrically conducted towards the direction of the energy storage capacitor. The adjusting switch tubeis configured to adjust the charging current provided by the charging inductor for the energy storage capacitor by changing the conduction duration of the adjusting switch tube, thereby adjusting thevoltage value of the end of the energy storage capacitor so as to adjust the laser power of the laser pulse. According to the invention, the structure of a drive circuit can be simplified, and the modulation speed of the peak power and pulse width of the laser pulse is improved, thereby achieving the miniaturization of the laser radar and the quick modulation of the peak power and pulse width of the laser pulse.

The invention provides a quantum communication optical path system and a quantum communication method. The method comprises the steps: at an Alice end, enabling signals to pass through an electro-optic phase modulator at the same time from two directions along a loop, and performing coding through a second polarization beam splitter; under the action of a second polarization beam splitter and a 90-degree Faraday rotator mirror,, enabling the polarization difference between the polarization when the optical signals (namely a first detection optical signal pulse and a second detection optical signal pulse) return to a Bob end through a communication channel and the polarization when the optical signals are emitted from the Bob end to be just 90 degrees, so the optical signals (namely the first detection optical signal pulse and the second detection optical signal pulse) can bypass phase intensity modulation modules (the intensity modulator and the phase modulator) through a first polarization beam splitter to directly reach a PMI polarization-maintaining interference ring, thereby solving the problem of mode crossing of an optical signal loop, and greatly improving the modulation speed of the circuit.

The invention relates to a dual-MOS structure silicon-based electro-optical modulator. The structure of the modulator comprises the following parts from top to bottom respectively: a top-layer silicon waveguide layer, a top layer insulated gate layer, a middle layer silicon waveguide layer, a bottom layer insulated gate layer, a bottom layer silicon waveguide layer, a buried oxide SiO2 layer and a Si substrate, wherein the top layer silicon waveguide layer and the bottom layer silicon waveguide layer are N-type doped silicon layers; the middle layer silicon waveguide layer is a P-type doped silicon layer; the middle part of the P-type doped silicon layer is provided with a light splitting layer which is divided into two layers with the same thickness; and the light splitting layer splits an incident beam into two beams of same light propagations. The structure also comprises a grounding electrode arranged on the N-type doped silicon layer and a metal electrode arranged on the P-type doped silicon layer, and the insulated gate layers are made of a SiO2 material. The dual-MOS structure silicon-based electro-optical modulator has quick modulation speed, high efficiency and small device dimension, can adopt different gate materials and different dimensions and can select different doping densities.

The invention discloses a multispectral co-phase error detection method based on pupil spatial modulation. The method can be used for co-phase error detection in a spliced telescope system. The methodcomprises the following steps: selecting a reference sub-pupil, and acquiring a point spread function of the reference sub-pupil, a point spread function of the remaining sub-pupil and a point spreadfunction of a system; solving partial co-phase error distribution of the system under the wavelength by adopting a reverse deconvolution method according to the obtained three point spread functions;changing the wavelength for multiple times, and solving the corresponding partial in-phase error distribution, and finally calculating the overall in-phase error of the system by using a multi-spectrum synthesis algorithm. According to the method, there is no need to additionally add a reference pupil on a synthetic aperture surface, the structure is simple and the efficiency is high; meanwhile,the phase difference is processed by adopting multiple wavelengths, so the 2*pi fuzzy influence can be effectively inhibited, and the detection range is enlarged.

The invention discloses an FLC-based hyperspectral all-polarization imaging device and method. The imaging device comprises a pre-posed imaging objective lens, a diaphragm, a collimator objective lens, a polarization modulation system, a Sagnac interference device, a post-posed imaging objective lens and a detector, which are arranged in sequence along the light path. The method comprises the following steps: 1) after passing through the pre-posed imaging objective lens and the collimator objective lens, incident light enters the polarization modulation system in the form of a collimated light beam; 2) the light beam passes through the polarization modulation system to obtain four interference images, and enters the Sagnac interference device; 3) the light beam is intervened by the Sagnac interference device; 4) the light beam enters the post-posed imaging objective lens and is imaged on the target surface of the detector; and 5) interference light intensity information of each object point is obtained from the target surface of the detector, and the interference light intensity information is processed to obtain spectral information and all-polarization information of each target point. The imaging device and method have the advantages of high luminous flux, high spectral resolution, high target resolution, quick modulation and obtaining the spectral information and the all-polarization information simultaneously and the like.

The invention discloses a broadband linear frequency modulation narrow linewidth fiber laser and an implementation method thereof. The implementation method comprises the steps that: a narrow linewidth seed source outputs linear polarization continuous laser with a wavelength of 1.5 microns, a radio frequency signal source generates a linear frequency modulation signal and sends the linear frequency modulation signal to a modulator drive, and the modulator drive loads the linear frequency modulation signal and a bias voltage to a double-parallel phase modulator; an output end of the narrow linewidth seed source is connected with the double-parallel phase modulator, the laser experiences linear frequency modulation in the double-parallel phase modulator, the output end of the double-parallel phase modulator is connected with an optical beam splitter, the output end of the optical beam splitter outputs a part of modulated laser to serve as radar local oscillation light, the output of the optical beam splitter is connected with an optical fiber amplifier, and the amplified laser is output from the output end of the optical fiber amplifier. The broadband linear frequency modulation narrow linewidth fiber laser is narrow in linewidth, large in modulation bandwidth, capable of meeting the use requirements of a synthetic aperture laser radar and a linear frequency modulation continuous wave laser radar, high in modulation speed and high in modulation linearity.