4456 results about "Optical filter" patented technology

The invention relates to the technical field of gas detection, and particularly discloses an industrial gas concentration detection system, which is used for solving the problems of signal attenuation, low detection precision, high cost and poor stability caused by environmental interference and multi-laser beam combination since a correlation type optical machine adopts a single-path and fixed compensation method and cannot measure multi-component gas at the same time. Comprising a transmitting end and a receiving end, a laser is arranged in the transmitting end, a red light generator is arranged in the transmitting end, an off-axis parabolic mirror is arranged on one side of the transmitting end, an optical filter is arranged above the off-axis parabolic mirror, a photoelectric detector is arranged above the optical filter, a first window is arranged on one side of the off-axis parabolic mirror, a second window is packaged in the receiving end, and a full-angle reflector is arranged on one side of the second window. The photoelectric detector is sequentially connected with a data inversion analysis module, a dynamic environment compensation module and an environment sensing module; by optimizing optical design and dynamic environment compensation, multi-gas concentration detection is realized.

The invention relates to a surface collapse monitoring system based on multi-parameter distributed optical fiber sensing, and the system comprises a monitoring module which comprises a plurality of fully distributed optical fiber sensors laid in a monitoring area, and an optical signal transmission and demodulation module which comprises a continuous spectrum laser, an optical switch, an optical amplifier, an optical filter, and a demodulation module. The data processing and analysis center comprises a data acquisition module and a collapse model modeling module, and the data acquisition module is used for performing acquisition and digital conversion on the optical signal demodulated by the demodulation module; the collapse model modeling module constructs a model according to the monitoring data and can predict the development trend of surface collapse; and the early warning and communication module communicates with a remote monitoring center. The monitoring system provided by the invention has the advantages of multi-parameter monitoring, high monitoring precision, suitability for large-scale laying, real-time response and the like, and can comprehensively and accurately reflect the real condition of surface collapse.

The embodiment of the invention provides a system for measuring a plane vector magnetic field, and the system comprises an optical path module which is provided with a laser, an optical fiber circulator, a long-pass optical filter and a photoelectric detector, a microwave module which is provided with a microwave source, a microwave amplifier and a microwave isolator, a signal processing module which is provided with a lock-in amplifier, and a magnetic generation device. The integration table device comprises a diamond NV color center sensor, a microwave antenna and two pairs of magnetic flux concentrators; during working, laser emitted by the laser device is output to the optical fiber circulator and then enters the diamond NV color center sensor so as to excite the diamond NV color center, and meanwhile, modulated microwaves which are output by the microwave source, are linearly amplified by the microwave amplifier and are transmitted again by the microwave isolator are used for regulating and controlling the electron spin state of the diamond NV color center so as to excite the diamond NV color center. The diamond NV color center outputs fluorescence with microwave regulation and control, and the fluorescence carries information of a plane vector magnetic field. The system can realize a high-isolation and high-sensitivity plane vector magnetic field measurement method.

The invention relates to the technical field of image processing, in particular to an image imaging method based on an anti-ambient light interference technology and image acquisition equipment thereof. According to the method, a photoelectric sensor is used for receiving a mixed optical signal reflected by a target, a tunable optical filter is used for extracting a reflected light component containing pulse coding characteristics, and an anti-interference characteristic pattern with a time dimension identifier is generated; based on the time dimension identifier of the anti-interference feature map, identifying an effective reflection region meeting a preset reflection characteristic threshold in the target scene, and marking a transient interference region generated by direct illumination of ambient light; and performing differential operation on the light intensity data of the effective reflection area and the spectral characteristics of the transient interference area, and reconstructing a target intrinsic image shielded by light. According to the invention, the imaging definition and the target identification reliability under severe illumination conditions such as backlight and strong light can be improved.

The invention discloses an inter-satellite laser communication load on-orbit receiving and transmitting optical axis coaxial self-calibration device and method, and belongs to the field of inter-satellite laser communication. Comprising a cube-corner prism, a coarse pointing mechanism, a beam expanding group lens, a color separation sheet, a fast reflecting mirror, a communication signal light emitting system, an optical filter, a light splitting sheet, an optical filter, a signal focusing mirror, a communication signal detector, a tracking focusing mirror and a tracking signal detector. Under the condition that beacon light is not used and a laser source is not additionally added, communication signal light is directly adopted to calculate and compensate the offset between the receiving optical axis and the transmitting optical axis through the cube-corner prism, the on-orbit alignment capture time is greatly shortened, and the cost, power consumption, size and weight of a self-calibration device are reduced.

A light absorber 10 has a transmission spectrum satisfying the following requirements (I), (II), (III), (IV), and (V) at an incident angle of 0°. The light absorber 10 has a haze less than 0.20%. (I) An average transmittance TA0deg(460-600) is 75% or more. (II) A shorter cut-off wavelength λH0deg(s) is in a range of 390 nm to 450 nm. (III) A longer cut-off wavelength λH0deg(L) is in a range of 600 nm to 680 nm. (IV) An average TA0deg(300-380) is 1.2% or less. (V) An average TA0deg(750-1000) is 1.2% or less.

The invention relates to a terahertz-Raman integrated detection system and method. The detection system comprises a fusion mainframe box and an integrated probe arranged at a sample detection end on the fusion mainframe box, a Raman spectrum module, a terahertz spectrum module, a terahertz optical module and a data analysis module are arranged in the fusion mainframe box; the Raman spectrum module is composed of a Raman laser, a Raman light filter, a Raman grating and a Raman detector which are sequentially connected through a light path; the terahertz spectrum module is composed of a terahertz femtosecond laser, a transmitting photoconductive antenna, a receiving photoconductive antenna and a terahertz detector which are sequentially connected through a light path; the data analysis module is in communication connection with the Raman detector and the terahertz detector and is used for synchronously processing data transmitted by the Raman detector and the terahertz detector. Compared with the prior art, the integrated probe synchronously collects two kinds of spectral data and carries out fusion processing on the two kinds of spectral data through the data analysis module, and the device has the remarkable effects that the device integration degree is high, the detection efficiency and accuracy are greatly improved, and the application range is wide.

The invention relates to the technical field of color sorters, and discloses a color sorter system based on double hyperspectral cameras, which comprises a hopper, a vibration feeder, a crawler belt conveyor belt, a hyperspectral camera detection module, an air injection system, a finished product bin and a waste bin, wherein the hopper is used for inputting materials; the vibration feeder is used for uniformly conveying materials to the crawler belt conveyor belt; the crawler belt conveyor belt is used for receiving materials conveyed by the vibration feeder and continuously conveying the materials forwards; and the hyperspectral camera detection module is used for carrying out image acquisition on the material under a uniform illumination condition. Compared with a color selector based on an RGB camera, the color selector provided by the invention has more accurate spectral characteristic representation, can obtain more and more comprehensive spectral information data and has more application scenes and development spaces, and compared with a color selector based on a near-infrared camera, the color selector provided by the invention has fewer cameras and optical filters, the structure is simpler, and the wave band selection is more convenient.

An on-chip mid-infrared micro-ring resonant cavity microfluidic spectrometer is integrated on a substrate material and comprises a spot size converter, an optical coupler, a microfluidic module, a micro-ring resonant cavity, a miniature thin-film resistance heater, a sequential control power supply module, an optical filtering system and a photoelectric detector array. Selective filtering is performed on an input optical signal, and the flow and flow velocity of liquid or gas to be detected are controlled by using the microfluidic module, so that selective absorption of spectral components of the liquid or gas to be detected is realized. In addition, the invention also discloses a mid-infrared integrated optical chip micro-fluidic multiphase detection device comprising the spectrometer and a detection method thereof, the device also comprises a pumping and reference light source module and an on-chip mid-infrared frequency comb generation module, a broadband frequency comb is generated as a light source, a photoelectric detector array is used for collecting signals, and the detection precision is improved. The detection and inversion of the type and concentration of multi-component liquid or gas to be detected are realized, and the on-chip, real-time and micro detection of multi-component substances is realized.

The invention discloses an underwater active polarization imaging device based on a liquid crystal phase retarder, which comprises a CCD (Charge Coupled Device) camera, an optical filter, a beam splitter prism, the liquid crystal phase retarder, a polarizer, a front lens and an annular active light source which are sequentially arranged on the same straight line, and the imaging device is arranged in front of a shot target at an object distance capable of clearly imaging; wherein the rotating table, the liquid crystal controllable phase delayer, the annular active light source and the CCD industrial camera are connected to a computer for control and image processing, and the underwater active polarization imaging device calculates a Stokes vector of a shot target by shooting a plurality of polarization images with different polarization angles and polarization states; according to the method, the image of the target object is acquired through the polarization information of the object, the influence of scattering absorption of underwater impurities can be eliminated, and an underwater high-definition image is presented through relative algorithm optimization.

The invention provides a method for detecting multi-gas concentration in exhaust gas and a gas filtering system, and relates to the technical field of gas detection. The method comprises the following steps: setting components and concentration of mixed gas according to characteristics of target detection gas, and injecting the mixed gas into a light filtering channel to eliminate illumination interference of a red light wave band so as to obtain first illumination; after a user detection instruction is obtained, the gas inlet valve is opened, the exhaust gas enters the detection chamber, the exhaust gas entering the detection chamber is detected through the gas automatic identification module, and the concentration of multiple target detection gases is estimated. Determining the target detection gas with the highest concentration, adjusting an optical filter to filter the first illumination to obtain second illumination, enabling the second illumination to penetrate through the exhaust gas to obtain third illumination, determining the concentration of the target detection gas according to the third illumination and the second illumination, and displaying the concentration on a screen in real time. In a complex gas emission environment, the influence of interference gas is eliminated, and the concentration of target detection gas is accurately detected.

An optical reception system according to an embodiment of the present invention may comprise: first to fifth lenses arranged along an optical axis from an object toward a sensing unit; and an optical filter spaced apart from the sensing unit and disposed between the third lens and the fourth lens, wherein the first to fifth lenses include aspherical lenses and spherical lenses, the number of which is greater than the number of the aspherical lenses, the optical axis distance from the optical filter to the surface of the sensing unit is D1, the optical axis distance from the sensor-side surface of the fifth lens closest to the sensing unit to the surface of the sensing unit is BFL and satisfies a mathematical expression: BFL < D1, the effective diameter of the first lens is larger than the effective diameters of the remaining lenses, and the effective diameter of the fourth lens is smaller than the effective diameter of the first lens.

The invention belongs to the field of optics, and discloses an optical module system for a port detection device, which comprises a shell, a first optical path assembly, a second optical path assembly, a third optical path assembly, a fourth optical path assembly, a first dichroscope and an optical fiber splitter are arranged in the shell, and the first optical path assembly and the second optical path assembly form a reflection mechanism. The third light path assembly and the fourth light path assembly form a transmission mechanism, each light path assembly comprises a light source, a condensing lens, an optical filter and a reflection unit which are sequentially arranged, the reflection units in the first light path assembly and the third light path assembly are reflectors, and the reflection units in the third light path assembly and the fourth light path assembly are second dichroscopes. According to the invention, multi-channel narrow-band light source output can be provided according to requirements, and a multi-channel optical fiber splitter is externally connected. The light source wave band can be selected and adjusted, and multiplexing of a single light source is achieved.

The preparation method of the short-wave-pass ultraviolet optical filter comprises the following steps: S1, cleaning a product serving as a glass substrate of a lens; s2, putting the lens into a tool clamp, and hanging the lens into a coating machine; s3, vacuumizing and radio frequency ion source cleaning are carried out; s4, a short-wave pass film system 80.04 H, 90.05 L, 75.25 H, 79.63 L, 66.91 H, 101.42 L, 52.56 H, 105.14 L, 59.19 H, 92.56 L, 62.15 H, 98.59 L, 55.4 H, 102.89 L, 63.02 H, 95.45 L, 60.9 H, 107.93 L, 58.64 H and 55.22 L is plated on the first face of the lens, electron beam evaporation and radio frequency ion source assistance are used for evaporation, the Ta2O5 deposition rate is 0.4 nm / s, and the SiO2 deposition rate is 1 nm / s; s5, cooling and taking out; s6, repeating the steps S1 to S3; s7, plating the second surface of the lens with an antireflection film system of 16.53 H, 26.98 L, 28.44 H and 76.55 L; and S8, cooling and taking out.

The invention relates to the technical field of optical elements, systems or instruments, in particular to a temperature field testing method based on combination of colorimetric temperature measurement and multispectral imaging, and solves the technical problems of low temperature field temperature measurement reconstruction precision and low temporal-spatial resolution of an existing temperature measurement method. The method comprises the following steps: determining a spectral range and a temperature measurement range of a temperature field of a solid engine combustion chamber by utilizing an LIBS (Laser-induced Breakdown Spectroscopy) technology, coupling and packaging a multispectral optical filter and a CMOS (Complementary Metal Oxide Semiconductor) sensor, calibrating a multispectral camera by utilizing a blackbody furnace, and acquiring a spectral image of the temperature field by utilizing the multispectral camera. And obtaining a two-dimensional temperature field of the combustion chamber of the solid engine by using a colorimetric temperature measurement method, and performing comprehensive evaluation. According to the invention, multispectral information of the solid propellant combustion chamber flame can be obtained, and high space-time resolution detection of the two-dimensional temperature field of the solid engine combustion chamber is realized.

The invention discloses a multi-pass optical filter and a preparation method thereof, and the method comprises the steps: selecting a main reference channel, and carrying out the difference frequency modulation excitation through narrow linewidth laser, and obtaining optical transmission coupling data; performing periodic disturbance detection on the observation channel to obtain spectrum drift associated data; modulating deposition power and air pressure according to the spectrum drift associated data to form a crosstalk suppression layer; forming a three-layer dielectric structure with increasing optical thickness and a periodically changing coupling regulation layer on the crosstalk suppression layer; and performing temperature modulation annealing treatment to form an inter-channel steady-state coupling structure, and establishing a spectrum drift compensation parameter. The technical scheme of the invention can systematically characterize the correlation drift of the multi-channel spectral characteristic along with the micro process or service disturbance, accurately quantify the coupling relationship between different passbands, and solve the technical problem that the correlation drift between the passbands cannot be completely captured in the existing discrete measurement mode. The phenomenon of'array misfocus' in a miniature multispectral system is effectively avoided, and the precision and stability of the multi-pass optical filter are improved.

The invention discloses a variable beam divergence angle laser communication terminal and a rapid capturing method thereof, and belongs to the technical field of optical communication equipment. Comprising a main telescope, a fine tracking fast reflecting mirror, a beam splitter, an optical filter, a beam splitter, a beacon receiving lens group, a beacon detector, a signal transmitting lens group, an advanced aiming fast reflecting mirror, a signal receiving lens group, a receiving optical fiber amplifier, a multi-core optical fiber splitter, an optical switch and a transmitting optical fiber amplifier, a signal light emitting light path, a beacon light receiving light path and a signal light receiving light path are formed; the signal light emission light path provides emission light beams through different mode field optical fibers and performs shaping and variable beam divergence angle emission on the emission light by using different paths of an emission mirror group, and the signal light receiving light path is used for completing collection, shaping, coupling and light amplification on input signal light. And the beacon light receiving optical path is used for collecting, shaping and converging the input signal light, and positioning a target light spot by using an image positioning detector. According to the invention, the remote capturing efficiency can be improved.

An optical filter includes: a substrate, an antireflection layer 1 including a dielectric multilayer film laminated on one main surface side of the substrate, and an antireflection layer 2 including a dielectric multilayer film laminated on the other main surface side of the substrate. The substrate includes a near-infrared ray absorbing glass and a resin film, the resin film includes a resin, a UV dye having a maximum absorption wavelength in 350 nm to 410 nm in the resin, and an IR dye having a maximum absorption wavelength in 700 nm to 850 nm in the resin, and the optical filter satisfies all of the characteristics (i-1) to (i-7).

The invention relates to the field of optical filter module performance testing, in particular to efficient testing equipment for optical filter precision machining, which comprises an outer cylinder, a support ring and the like. According to the efficient test equipment for optical filter precision machining, high-temperature water mist is sprayed to the surface of the optical filter module, the light transmitting effect of the optical filter module is continuously detected through the optical sensor, suction work is conducted in the outer cylinder through the annular air conveying pipe, meanwhile, the vibration unit continuously generates vibration on the surface of the optical filter module, and the optical filter module is subjected to precise machining. The penetration speed and the diffusion range of high-temperature water mist in the optical filter module are increased, and the detection effect on the waterproof performance of the optical filter module is enhanced by quickly, accurately and intuitively feeding back the waterproof performance of the optical filter module. The technical problems that the waterproof performance testing efficiency of the optical filter module is low due to long-time waterproof testing work, and whether high-temperature water mist permeates in the optical filter module cannot be visually observed are solved.

The invention discloses a laser frequency stabilization system based on Faraday anomalous dispersion atomic filtering, which is used for carrying out frequency stabilization on phase modulation multi-sideband laser, and comprises a frequency doubling laser unit which is configured to comprise a fundamental frequency seed light source, an electro-optical modulator, a fundamental frequency amplifier and a frequency doubling crystal; the light splitting module unit is configured to split the frequency doubling light into a main output light path and a monitoring light path; the atomic optical rotation filter is located on the monitoring light path and is configured to maintain the purity of the frequency-stabilized laser spectrum through purification treatment under the control of the axial magnetic field and the temperature; the frequency stabilization unit is configured to be a frequency stabilization light path and a servo system, and the frequency stabilization light path is used for obtaining laser frequency information and generating an error signal; the servo system is used for controlling the frequency of the fundamental frequency seed light source according to the error signal feedback. According to the laser frequency stabilization system provided by the invention, the spectrum purification and frequency stabilization precision can be improved, so that high-frequency stability locking is realized.

The invention relates to a three-waveband medium-long wave infrared optical filter and a preparation method, the three-waveband medium-long wave infrared optical filter comprises a front film system, a substrate and a back film system, and the substrate is located between the front film system and the back film system; the front film system is formed by alternately overlapping germanium layers and zinc selenide film layers; and the back film system is formed by alternately overlapping germanium layers and zinc selenide film layers. According to the invention, the light energy of three wave bands of 3780-4000 nm, 4500-4900 nm and 7850-9500 nm is improved, the luminous flux of other wave bands is well inhibited, the technical problem of infrared filtering windows in some special infrared spectrum detection systems is solved, and a new scheme is provided for the application of the infrared spectrum detection systems.

The invention relates to a backside illuminated image sensor preparation method and a backside illuminated image sensor, and relates to the technical field of integrated circuits, the backside illuminated image sensor preparation method comprises the steps that a substrate comprising a first top surface is provided, and the first top surface of the substrate comprises first isolation lamination layers and first photosensitive lamination layers which are alternately arranged along a first direction parallel to the first top surface of the substrate; the first photosensitive laminated layer comprises at least three sub photosensitive layers which are alternately laminated along a second direction away from the substrate; in the process of forming a plurality of second photosensitive laminations right above the plurality of first photosensitive laminations, forming a plurality of second isolation laminations right above the plurality of first isolation laminations; the second photosensitive lamination layer comprises at least two sub photosensitive layers which are alternately laminated along a second direction; and forming a plurality of grating laminations right above the plurality of second isolation laminations, and then forming optical filters between the adjacent grating laminations along the first direction. According to the embodiment, the electron concentration of the photosensitive area is increased, and the photosensitive performance of the BSI image sensor is improved.

The invention discloses a multispectral depth camera, which comprises a combined beam splitting system, a multispectral imaging module, a depth imaging module, a precision lens and a data processing unit, the combined light splitting system comprises a dichroscope which is arranged in a light path and is used for dividing incident light into two paths, and the two paths are respectively guided to the main RGB sensor and the multispectral imaging module; the multispectral imaging module comprises a special mosaic optical filter and an image sensor; the depth imaging module comprises a main RGB sensor and an auxiliary RGB sensor; and the data processing unit is arranged behind the multispectral imaging module and the depth imaging module and is used for receiving image electric signals output by the multispectral imaging module and the depth imaging module. The method has the advantages and benefits that the multispectral information and the depth information can be accurately and quickly fused in real time, and the problems that after an independent sensor obtains the multispectral information and the depth information, image registration fusion processing is complex and low in precision are well solved.

Provided is an inspecting apparatus for semiconductor device including a chamber, a substrate stage within the chamber and configured to load a test wafer, the test wafer including a plurality of wiring layers, a milling device configured to partially remove the test wafer, and a measuring device including a body portion, a light source configured to irradiate an incident light, an objective lens, a lens assembly having a plurality of optical filter and an optical splitter, wherein the lens assembly is configured to introduce the incident light such that the incident light is emitted on the test wafer; and a polarization camera configured to scan the test wafer by receiving reflected light reflected from the test wafer, wherein the measuring device is configured to measure polarization characteristic of the reflected light and uniformity of the test wafer.

Sleep-aiding eyewear that prevents light which inhibits melatonin production from reaching the eye is described. The eyewear that is the object of the present disclosure has improved visibility over other methods of cutting off melatonin-inhibiting wavelengths of light, which enables the user to perform tasks, such as reading and typing, uninhibited. This is achieved in some embodiments using a Bragg grating comprising multiple layers of alternating reflective index material as a surface coating on the lens. This may be combined with lens-tinting, or antireflective coatings, in the eyewear. Furthermore, transition lenses which block melatonin-shifting light when there is a suitable external stimulus, such as blue light from a light emitting diode, are described. The presently described filters are also useful for electronic displays and functional light-transmitting materials.

The utility model discloses an infrared narrowband optical filter with a working wave band of 3900-4100nm, the infrared narrowband optical filter comprises a substrate, a main film system and a secondary film system, the main film system is arranged on a first side of the substrate, the secondary film system is arranged on a second side of the substrate, the second side is opposite to the first side, the main film system is arranged on the first side, and the secondary film system is arranged on the second side of the substrate. The main film system comprises 26 high-refractive-index film layers and low-refractive-index film layers which are alternately overlaid outwards from the substrate according to the structure of the main film system, and the secondary film system comprises 38 high-refractive-index film layers and low-refractive-index film layers which are alternately overlaid outwards from the substrate according to the structure of the secondary film system. The infrared narrow-band optical filter can have a good light transmission effect within the wavelength range of 3900-4100 nm, the average transmittance is larger than 94%, the infrared narrow-band optical filter is highly cut off within the wave bands of 1000-3700 nm and 4300-6500 nm, the average transmittance is smaller than 1%, stray light interference can be effectively reduced, and the sensitivity and the detection efficiency of an infrared detector are improved.

The invention provides a radiation temperature measurement device and method based on dynamic calibration, and relates to the technical field of radiation temperature measurement. The device is used for measuring temperature information of a hot end component and comprises a first lens group, a temperature measuring probe, a second lens group, an optical switch, an optical filter, a photoelectric detector, a pre-amplifier, an acquisition monitoring system and a controller, after passing through the optical filter, a corresponding temperature measurement characteristic wavelength is obtained; the photoelectric detector is of a thermoelectric refrigeration type, the temperature measurement characteristic wavelength is incident to the photoelectric detector for detection to obtain a corresponding electric signal, the electric signal is amplified into a collectable voltage signal through the pre-amplifier, and the collection monitoring system carries out collection and post-processing to obtain temperature information of the hot end component; the optical switch is arranged at the front end of the optical filter and is controlled to be turned on or turned off through the controller, and the controller is controlled by the collecting and monitoring system.

Disclosed in the present invention are a multispectral light field imaging system, and a three-dimensional temperature field measurement method and measurement system. The multispectral light field imaging system comprises: a primary lens, a micro-lens array, a first relay lens, a dichroic mirror, a second relay lens, a third relay lens, a first image sensor, a first optical filter, a second image sensor and a second optical filter, wherein the micro-lens array is located at an image plane of the primary lens; the first relay lens, the second relay lens and the third relay lens together form a 1:1 relay lens group imaging system on an optical path of a spectral band I and an optical path of a spectral band II; an angle of 45° is formed between the dichroic mirror and an optical axis; and the first image sensor is located at a focal plane of the second relay lens, and the second image sensor is located at a focal plane of the third relay lens. The present invention realizes the collection of multispectral light field data while maintaining the amount of light field data of each spectrum unchanged, such that an instantaneous three-dimensional temperature field of a flow field can be measured.

The embodiment of the invention relates to an electronic paper display panel, an electronic paper display panel preparation method and electronic paper equipment. The electronic paper display panel comprises an upper substrate, a lower substrate, an optical filter layer, a transparent electrode layer and a pixel electrode layer, an optical filter layer is arranged on the surface, opposite to the lower substrate, of the upper substrate, and a transparent electrode layer, a plasma display cavity and a pixel electrode layer are sequentially arranged between the optical filter layer and the lower substrate; a plasma screening net, supporting microspheres and plasma are arranged in the plasma display cavity, the supporting microspheres make contact with the upper surface and the lower surface of the plasma display cavity, and the supporting microspheres are connected with the plasma screening net; the plasma comprises a first type of particles and a second type of particles, and the mesh aperture of the plasma screening net is smaller than the size of the first type of particles and larger than the size of the second type of particles. According to the embodiment of the invention, the possibility that two kinds of particles are gathered is reduced, the light absorption efficiency is improved, the plasma screening net also plays a role in supporting the plasma display cavity, and the mechanical strength of the panel is improved.

The invention provides a high-temperature-resistant optical filter and a preparation method thereof. The high-temperature-resistant optical filter comprises a substrate, a first high-temperature-resistant film layer, an optical filter film layer and a second high-temperature-resistant film layer, and the first high-temperature-resistant film layer and the second high-temperature-resistant film layer comprise a plurality of SiO2 thin film layers and Al2O3 thin film layers which are sequentially arranged in a staggered mode; the SiO2 thin film layers and the Al2O3 thin film layers are alternately arranged, expansion or contraction of each thin film layer can be mutually compensated by the adjacent layers when the temperature changes, thermal stress between single layers can be offset to a certain degree, and therefore the sensitivity of the whole film system to the temperature changes is reduced, the thin film with high thermal stability is formed, and the service life of the thin film system is prolonged. The phenomenon that the optical filter film layer is broken, warped and even falls off and fails due to high temperature can be avoided under the high-temperature test of 600-1000 DEG C; the problems of substrate deformation, film layer failure, falling and the like possibly existing in a traditional optical filter in a high-temperature environment are solved in a targeted manner.