48results about How to "Wide working band" patented technology

The invention relates to a modulation format identification method and system based on signal spectral characteristics. The system comprises an optical amplifier (OA), an optical spectrum apparatus (OSA) and a data signal processing (DSP) system. First, an optical signal to be identified enters the OA and is amplified to have certain power, then injected to the OSA; center frequency estimation of the optical spectrum output from the OSA is carried out; using the center frequency as a reference, optical signal spectrums having a frequency range of +/-100GHz are intercepted; a characteristic vector of the optical sample is abstracted through a principal component analysis (PCA) algorithm module; the characteristic vector is input in an algorithm identification module of a pre-trained support vector machine (SVM) to determine the modulation formats and speed of the optical signal under test. The provided method requires no prior information to work and is suitable for switch modulation and advanced modulation format signals; no high speed detector is required; the method has large signal transmission damage tolerance, simple structure and wide application range.

The invention relates to an optical signal modulation format recognition method and system based on nonlinear digital processing in the field of optical fiber communications. The system comprises a TDC, an OA, an optical filter, a high-speed optical detector, a low-speed asynchronous sampler, an analog-digital converter and a main control module. The main control module drives the TDC to generate a series of chromatic dispersion values, N sampling digital signals p1, p2, ... and pN are recorded under each chromatic dispersion value, and an output signal <Pout> is calculated according to the formula that <Pout>=1/N *Sigma Nj=1(kpj)<n>, wherein n is the order and k is the adjusting coefficient; the <Pout> values obtained under the chromatic dispersion values are stored to be feature value arrays in order of the chromatic dispersion values, the feature value arrays are matched with feature value array samples of signals of the known modulation format, and therefore the modulation formats of input optical signals are judged. The method and system are applicable to signals of various modulation formats and rates, the working waveband is wide, greater tolerance is achieved for signal transmission chromatic dispersion and OSNR degradation, and the requirement for the rates of sampling and the analog-digital converter is low. The method and system have the advantages of being simple in structure, high in cost performance and wide in application range.

The invention relates to a high-sensitivity remote sensing image spectrometer which can obtain target image, interference spectrum and polarization information, composed of a polarization interferometer, an image lens and an area detector which are coaxially arranged along incident light. The polarization interferometer is composed of a polarizer, Sawa polariscope and a checker, wherein the Sawa polariscope comprises two natural uniaxle negative crystal Sawa plates in same thickness, vertical optical axis, and corner as 45 degrees with the system optical axis, the polarizer and the checker are both composed of two wedge natural uniaxle negative crystal GeLanTaLe lens with an air space. The signal output of the detector is connected with an external computer signal processing system. Compared with prior art, the invention eliminates an advanced optical system and a slit of traditional device, while the invention uses the Sawa polariscope made from natural crystal as a horizontal shearing beam splitter, with simple structure, small volume, high flux, high signal/noise ratio, high detection sensitivity, high resolution, wide spectrum, and strong detecting ability on remote target and weak signal.

The present invention discloses a visible infrared broad band absorber and a preparation method thereof. The device is formed by a multilayer structure consisting of a metal bottom layer, a polymer granular layer, a metal interface layer, a dielectric layer and a metal outer layer in order from a substrate to up. The operating wavelength of the absorber can cover the visible light wave band ( 0.4-0.8[Mu]m) and shortwave infrared band ( 1.1-3[Mu]m), medium wave infrared band ( 3-6[Mu]m) and long wave infrared band ( 6-14[Mu]m). The peak value absorptivity A can reach 99%, and the full width at half-maximum can reach 2[Mu]m. The visible infrared broad band absorber is high in absorption efficiency, wide in operation band and adjustable in wavelength; the visible infrared broad band absorber is not sensitive to incident light polarization and angle; and the visible infrared broad band absorber is simple in technology and low in cost, can perform large-scale preparation and can be grown on a flexible substrate, etc.

The invention provides a medium-short wave broadband infrared optical system and a remote sensing optical device, which adopt a cylindrical primary imaging system configuration. The optical system iscomposed of four spherical mirrors. All elements are arranged on the same optical axis. The optical system has the characteristics of wide working waveband, compact structure, high suitability, high imaging quality, and transfer function reaching or close to the diffraction limit and the like.

The invention relates to a technology for measuring the modulation transfer function of an optical system, in particular to a device and method for measuring the modulation transfer function of a large-numerical aperture micro objective. An image analyzer (11) of the device comprises a scanning knife edge (8), a scanning controller (9), an integrating sphere (10), a semiconductor photoelectric detector (12) and a phase-locking amplifier (13), wherein the scanning knife edge (8) is installed in front of the opening of the integrating sphere (10); the scanning controller (9) receives control signals sent by a control and data processing system (14) to drive the knife edge to move; and the semiconductor photoelectric detector (12) is installed on the inner wall of the integrating sphere (10), and current signals output by the semiconductor photoelectric detector (12) are processed by the phase-locking amplifier (13) and then input to the control and data processing system (14). The device has the advantages of simple structure, good function expansibility, wide working waveband and convenient use and can also be used for measuring the modulation transfer function of the optical system.

The invention provides a parallel-connection flat field grating working in a soft X-ray wave band and a design method of the parallel-connection flat field grating working in the soft X-ray wave band. Two different flat filed gratings G1 and G2 are made on a same base to form the integral parallel-connection flat field grating. The grating works under the condition of grazing incidence and is applicable to the soft X-ray wave band. On the basis of the aberration theory of concave gratings, work parameters such as incidence distances, incidence angles and imaging positions of the G1 and the G2 are optimized to be completely the same, and therefore the G1 and the G2 can work simultaneously. The work wave band of the parallel-connection flat field grating is the sum of the work wave band of the G1 and the work wave band of the G2, and thus the work wave band of the grating can be effectively expanded. The parallel-connection flat field grating solves the problem that a flat filed grating is narrow in work wave band and meanwhile provides an effective technology for simultaneously measuring a broad spectrum of soft X-rays.

The invention relates to a self-adaptive optical system. The self-adaptive optical system comprises a reflector group, a spherical mirror, a first-stage beam expander group, a first-stage tracking unit, a second-stage tracking and high-order aberration closed-loop correction unit and an imaging unit, the first-stage tracking unit comprises a first fast control reflector, a first spectroscope, a tracking imaging lens and a short wave infrared tracking camera; and the second-stage tracking and high-order aberration closed-loop correction unit comprises a second fast control reflector, a second-stage beam expander group, a piezoelectric deformable mirror, a third-stage beam expander group, a second spectroscope, a first Shack-Hartmann wavefront sensor beam shrinking lens, a Hartmann field diaphragm, a second Shack-Hartmann wavefront sensor beam shrinking lens, and a Shack-Hartmann wavefront sensor. The problem that the self-adaptive optical system cannot work normally in the visible light band in the background of strong daylight in the daytime is solved.

The invention belongs to the field of infrared guide head testing, and particularly relates to a minitype infrared target simulation device capable of achieving miniaturization of infrared target simulators and simulation of certain infrared targets. The minitype infrared target simulation device comprises an optical collimation system, an electric target and a blackbody. The optical collimation system comprises a lens cone (1), a lens installing assembly (2), a lens cover (3), a secondary lens installing assembly (4), an electric target wheel (5), a connecting plate (6), an off-axis parabolic reflector (7) and a plane reflector (8). The lens installing assembly (2) is arranged on the left side of the interior of the lens cone (1). The lens cover (3) is arranged on the left side of the lens installing assembly (2). The off-axis parabolic reflector is arranged on the right side of the lens installing assembly. The secondary lens installing assembly is arranged on the right side wall of the lens cone. The plane reflector is installed on the secondary lens installing assembly. The connecting plate is arranged on the lens body of the lens cone. The electric target wheel is arranged above the plane reflector and the outer side of the lens cone wall. The blackbody is arranged above the electric target wheel.

The invention discloses an external stray light testing device and method of an infrared optical system. The external stray light testing device comprises a light source, a collimator, a rotary table,a sliding guide rail, a first bracket, a second bracket, a lens mounting seat, a microscope system and a detector; during a test, the external stray light testing device of the infrared optical system is placed in a darkroom, light rays of the light source are reflected by a secondary reflecting mirror and main reflecting mirror in the collimator in sequence and changed into parallel beams, the collimator, the infrared optical system, the microscope system and the detector are located on a same optical axis through adjustment, the detector records image data, external stray light is introduced from different perspectives respectively, and the detector records the image data repeatedly. The external stray light testing device and method of the infrared optical system have the advantages that the principle is simple, various medium-wave infrared optical systems are in common use, the external stray light of the infrared optical system can be measured qualitatively and quantitatively, and the inhibition level of the external stray light by the infrared optical system is accurately evaluated.

The invention relates to a large aperture uniaxial crystal refractive index uniformity measurement apparatus and a method thereof. A collimating mirror, a polarizer and a semitransparent mirror are sequentially arranged in the emitting light path of a laser; the semitransparent mirror reflects and transmits light incident to the semitransparent mirror to respectively form reflected light and transmitted light; a convergent mirror is arranged in the path of the reflected light and converges the reflected light into an integrating sphere power meter; a beam compressing system object lens, a beam compressing system ocular lens and a Shack-Hartmann wavefront sensor are arranged in the path of the transmitted light; a large aperture uniaxial crystal to be measured is placed between the polarizer and the semitransparent mirror; and a computer is respectively connected with the integrating sphere power meter, the Shack-Hartmann wavefront sensor and the large aperture uniaxial crystal to be measured. The apparatus and the method can realize the large aperture uniaxial crystal refractive index uniformity measurement without being restricted by wavelength or being influenced by extraneous environment airflow and vibration, and well guarantees the measurement precision.

The invention discloses a visible-infrared broadband absorber and a preparation method thereof. The absorber comprises a substrate; a polystyrene pellet single-layer film layer and an alternating filmlayer formed by mutual alternating of metal absorption layers and non-metal dielectric layers are arranged successively on the substrate from top to bottom; a metal dielectric layer approaches the bottom polystyrene pellet single-layer film layer; each metal absorption layer is formed by one or more metal absorbing layer units; and each non-metal dielectric layer is formed by one or more metal absorbing layer units. The absorber has advantages of high absorption efficiency, wide working band, simple process, low cost and large area preparation and the like. Compared with the traditional broadband absorber, the absorber having a compact multi-layer film structure has the following beneficial effects: the production cost is lowered obviously; the production cycle is shortened substantially;and large-scale batched production can be realized.

The invention relates to an optical wave plate with low wavelength sensitivity, large size and true zero order as well as a preparation method and application of the optical wave plate. After the caliber and the thickness of the wave plate are determined, corresponding double refraction can be obtained according to the types of the wave plates and the central operating wavelength and further a space chamfer of a crystal is determined. The method has the greatest characteristics that the tangent direction of the crystal is flexibly selected according to the size of a device, and a traditional mode of processing a crystal wave plate along a fixed tangent direction is abandoned. Compared with a current widely-used crystal wave plate, the wave plate provided by the invention has the advantagesof convenience in processing, low cost, large size, high strength, low wavelength sensitivity and the like, is particularly suitable for phase retard and polarization conversion of large-caliber andwide-spectrum laser and is expected to realize important application in multiple optical and laser systems.

The invention discloses a compact type spectrum imaging method and system used for three-dimensional optical imaging. An imaging beam emitted by a to-be-detected object is converged and imaged to a convex reflection grating through a first concave reflector, and then the imaging beams with different wavelengths are irradiated to a second concave reflector through the light splitting and diverged imaging, the imaging rays with different wavelengths reach an aspheric surface field lens through further converging and imaging; after the field lens corrects the residual aberration, the spectrum images with different wavelengths of the to-be-detected object are converged on a focal plane detector. The imaging system provided by the invention is only composed of three reflecting elements and an aspheric lens, the processing difficulty and the adjustment difficulty of the system are simplified, and the accumulative error produced by adjustment is reduced. The convex reflecting grating is prepared by adopting a holographic record method, the balance and fine correction of the astigmatism and other optical aberration can be realized through joint optimization, the method has the advantages of being uniform in chromatic dispersion, large in relative aperture, high in resolution, good in imaging quality, free from ghost image, compact in structure and convenient to carry.

The invention relates to the field of optical fiber communication, in particular to an identification method and system for polarization-multiplexed optical signals and non-polarization-multiplexed optical signals. The identification system comprises an optical filter, a dispersion module, a high-speed optical detector, a sampler, an analog-digital converter and a digital signal processing module. The identification method comprises the steps of extracting a channel to be identified, adding a set dispersion value to the signals to be identified, acquiring the time domain digital sampling values of the signals, calculating and outputting a signal power distribution histogram after normalization processing, finding out the abscissa corresponding to the maximum value of the histogram, and identifying the polarization-multiplexed optical signals and the non-polarization-multiplexed optical signals according to the comparison value of the abscissa of the maximum value and a judgment threshold value. The identification system is suitable for the signals with various rates and modulation formats and wide in working waveband, has high tolerance about signal quality deterioration caused by optical fiber dispersion, polarization mode dispersion and amplifier noise in the signal transmission process, and has the advantages of being simple in structure, high in cost performance, wide in application range and convenient and fast to use.

The invention discloses a light-operated optical switch which comprises a magnetic base, a graphene sheet with a notch and a driving light source, the graphene sheet is arranged on the magnetic base in a suspended mode under the action of a magnetic field, and the graphene sheet is provided with the driving light source used for driving the graphene sheet to move in the circumferential direction.The advantages of the light-operated optical switch are that: by controlling light irradiation and changing the deflection of the magnetic polarization direction of the graphene sheet, the graphene sheet rotates under the action of a magnetic field such that the regulated light passes through or does not pass through the notch to realize the modulation of the controlled light, and the light-operated optical switch can realize the simultaneous modulation from ultraviolet to infrared spectrum ranges, and is high in modulation speed and modulation efficiency.

The invention relates to a visible broad-spectrum depolarizing beam splitter. The beam splitter consists of an optical glass substrate and a beam splitting film, wherein the beam splitting film consists of the following 10 film layers sequentially from inside to outside: a 1st layer: a dielectric material Al2O3 film layer; a 2nd layer: a metal material Ag film layer; a 3rd layer: a dielectric material TiO2 film layer; a 4th layer: a dielectric material SiO2 film layer; a 5th layer: a dielectric material TiO2 film layer; a 6th layer: a dielectric material Al2O3 film layer; a 7th layer: a dielectric material MgF2 film layer; an 8th layer: a dielectric material TiO2 film layer; a 9th layer: a dielectric material Al2O3 film layer; and a 10th layer: a dielectric material MgF2 film layer. Through the beam splitter, the processing difficulty is effectively reduced, the processing cost is lowered, and the design production is facilitated; and moreover, the film layers are of good hardness and firmness, the working band is 450-650nm, the permeation-reflection ratio is 45:45, and the difference between component S and component P is less than +/-5%.