132results about How to "Reduced scattering loss" patented technology

The invention provides a micro-droplet sensing device and a method using the same to measure refractivity. A single mode fiber forms a taper area through tapering, two ends of the single mode fiber are connected with a wide-spectrum light source and a spectrograph respectively, the taper area is placed in environment liquid, and annular core fiber optical tweezers control a micro-droplet to be close to the taper area; light emitted by the wide-spectrum light source is transmitted in the single mode fiber, is coupled into the micro-droplet by means of an evanescent field when going through the taper area and generates resonance in the mode of an echo wall, transmission light intensity at a resonance wavelength is reduced sharply to form a resonance valley, and the spectrograph is used to collect transmission light for spectrum analysis. The annular core fiber optical tweezers are utilized to control the micro-droplet to enable the same to form a perfect ball cavity, so that the problem that a solid ball echo wall sensor cannot form echo wall resonance due to unsmooth and defective surface of a solid ball is solved, and the micro-droplet is more sensitive to environment changing. The micro-droplet sensing device has wide application in the aspect of environment monitoring.

The invention discloses a parallel model converter and a light splitter composed of the same, the solved technical issue is about reduction of optical field loss at a split location of the light splitter in SPI integrated optical loop. The inventive parallel mode converter has parallel multi-paths waveguide ridges distributed on an optical planar waveguide, each parallel multi-paths waveguide ridge is gradually widened in width of ridge waveguide from an input end to an output end. The light splitter is formed by sequentially connecting an incident coupling light waveguide, a single-channel mode converter, a lateral free propagation region and a mode converter, the optical planar waveguide of the mode converter is provided with the parallel multi-paths waveguide ridges the width of which is gradually widened from the input end to the output end. Compared with the prior art, the invention has the structure of parallel multi-paths waveguide ridges the width of which is gradually widened from the input end to the output end, which lowers scattering loss at the split location, and the light wave can avoid from being scattered by silicon dioxide between silicon channels in the process of conversion.

The invention relates to a free-etching oxidation manufacturing method of an SOI submicron ridge optical waveguide back-taper coupler, comprising the following steps: (1) oxidizing a silicon dioxide layer on SOI top-layer silicon; (2) forming a mask image on the silicon dioxide layer by a photoetching technology, wherein one end of the mask image is rectangular and the other end of the mask image is tapered by an etching technology; etching the silicon dioxide layer which is not protected by the mask image; and then forming a rectangular area and a tapered area of silicon dioxide protected by the mask image; (3) removing the mask image which is remained on the SOI top-layer silicon to form a sample; (4) oxidizing the sample, and oxidizing the etched SOI top-layer silicon under the etched silicon dioxide layer to a predetermined height so as to form a ridge waveguide flat area; (5) forming a ridge waveguide inner-ridge area on the SOI top-layer silicon protected by the tapered area of the silicon dioxide layer to form a slab waveguide back-taper structure which is connected with the inner-ridge area in a natural transition mode, and thus completing the natural integration of the ridge waveguide and the back-taper coupler.

The invention discloses an infrared double frequency sulfur-system devitroceram and preparing method, which is characterized by the following: It is prepared by the raw material of GeS2, Ga2S3 and CdS (GeS250-90%, Ga2S35-25% and CdS 5-25% in mole percent); The total content of raw material is 100 moles. The preparing method comprises the following steps: preparing sulfur-system glass; making heat treatment with the temperature higher than glass transformation temperature and lower than glass crystallization temperature; keep the course of germination and crystallization; sepearating out the a good deal of one-size and sub-micron weighting infrared double frequency crystal; preparing the sulfur-system devitroceram with infrared transmitting and double frequency function. The infrared double frequency sulfur-system devitroceram has wide penetrant window (0.45-12 mum). The invention simplifies the craft, which reduces the production circle.

The invention discloses a low-loss large-effective area single mode fiber and a manufacturing method of the low-loss large-effective area single mode fiber, and relates to the field of optical fibers. The low-loss large-effective area single mode fiber comprises a quartz glass cladding, an internal coating and an external coating, wherein the quartz glass cladding, the internal coating and the external coating are arranged in sequence from inside to outside; the inside of the quartz glass cladding comprises a first fiber core area, a second fiber core area, a third fiber core area, a fourth fiber core area and a refractive index concave cladding, wherein the first fiber core area, the second fiber core area, the third fiber core area, the fourth fiber core area and the refractive index concave cladding are arranged in sequence from inside to outside; the refractive index concave cladding is subjected to deposition through a PCVD process; the quartz glass cladding is manufactured through an OVD process or a sleeving process. According to the low-loss large-effective area single mode fiber and the manufacturing method of the low-loss large-effective area single mode fiber, the scattering loss of the low-loss large-effective area single mode fiber and the additional loss of the low-loss large-effective area single mode fiber in a bent state can be reduced; due to the fact that the spire distribution of fiber core basic mode electromagnetic field power is adjusted into flattop distribution, optical power density is reduced, the effective area of the low-loss large-effective area single mode fiber is enlarged, the nonlinearity of the low-loss large-effective area single mode fiber is reduced, the incident power of an optical fiber communication system is increased by 0.4-2.6 dB, and the low-loss large-effective area single mode fiber is suitable for mass production.

The invention provides a high-speed VCSEL laser epitaxial structure. The laser epitaxial structure comprises a GaAs substrate; a GaAs buffer layer, an N type doped DBR, an active layer, an oxidization limiting layer, a P type doped DBR and an ohmic contact layer are deposited on the GaAs substrate by adopting MOCVD in sequence; and the oxidization limiting layer is formed by multiple Al<1-x>Ga<x>As epitaxial layers with freely adjustable Ga components, wherein X is the Ga element component. According to the laser epitaxial structure, the multiple layers of Al<1-x>Ga<x>As with certain thickness and jumping components are adopted to form the oxidization limiting layer; and the front-end shape of the oxidization limiting layer can be changed by adjusting the components in each layer of Al<1-x>Ga<x>As, so that a lens structure can be formed at the front end of the oxidization limiting layer, and photon scattering loss can be lowered, thereby improving the modulation bandwidth of the VCSEL. The laser epitaxial structure has the following advantages: 1) by adjusting the ratio of Ga in the oxidization limiting layer, the oxidization rate of the oxidization limiting layer is lowered, the oxidization can be controlled easily, and the product yield of the VCSEL chip is improved; and 2) the oxidization limiting layer is high in thickness and low in intrinsic stray capacitance.

The invention relates to a photometric analyzer based on a light guide metal capillary and a detection method thereof. The analyzer comprises a light source, a light detector and the light guide metal capillary, and is characterized in that a light wave can be reflected on the side wall of the light guide metal capillary, a detection light beam emitted by the light source is restricted in the light guide metal capillary for transmission through total reflection on the side wall of the light guide metal capillary, and the light detector is used for receiving the detection light beam emitted out from the light guide metal capillary; a sample inlet is formed in one end of the light guide metal capillary, and a sample outlet is formed in the other end of the light guide metal capillary. The analyzer utilizes the light guide metal capillary to guide the transmission of the detection light beam and a sample to be detected; the total reflection for light on a metal surface is not limited by critical angle, and corrugated fluctuation on the inner surface of the metal capillary enables the incident angle of the detection light beam to change, so that the transmission light path of the detection light beam in the sample can be greatly increased, and the detection precision is improved.

The invention provides a method for vacuum sintering preparation of yttrium aluminium garnet (Y3Al5O12, YAG)-based transparent ceramics under a non-annealing mechanism based on a few Mg single sintering aid system. A small quantity of Mg is taken as a single sintering aid, and a single-step vacuum sintering method is adopted to prepare the YAG transparent ceramics with favorable optical quality and fine grains without later-stage annealing treatment.

The invention relates to a preparation method for a saturable absorption mirror based on a large-sized graphene. The preparation method comprises the following steps of: preparing a single layer of graphene film on a Cu foil; rotationally coating polymethylmethacrylate (PMMA) on the graphene film; after hot drying, placing into a FeCl3 solution and soaking at room temperature; cleaning; moving the graphene film and the PMMA on the graphene film to a laser high-reflectivity mirror; and blowing to the surface of the laser high-reflectivity mirror through weak airflow of an air gun. The preparation method is simple, high in efficiency, high in anti-damage threshold value and large in area. The graphene of the prepared saturable absorption mirror can maintain the integrated chemical structure and the graphene has the centimeter size.

The embodiment of the invention discloses a photodiode and a manufacturing method thereof, relating to the field of opto-electrical technology, wherein the photodiode is capable of reducing the energy loss. The photodiode comprises a substrate positioned on a bottom layer, a lower cladding layer boss covering the substrate, an incident wave core guiding layer covering the lower cladding layer boss, an upper cladding layer covering the incident wave core guiding layer, an optical matching layer positioned above the upper cladding layer and an avalanche photodiode positioned above the middle part of the back end of the optical matching layer, wherein the width of the lower cladding layer boss at the tail end in the incident wave direction is wider than that of the beginning end in the incident wave direction, both sides of the lower cladding layer boss at the tail end in the incident wave direction are parallel, and both sides of the lower cladding layer boss at the beginning end in the incident wave direction are parallel; and the optical matching layer comprises an optical matching layer front end and an optical matching layer back end, wherein the optical matching layer front end comprises at least one air seam extended along the incident wave direction, and the optical matching layer front end is divided into characteristic units partitioned by the air seams. The embodiment of the invention is applied to manufacturing the photodiode.

The invention relates to a low-loss deep-ultraviolet multilayer film production method, belongs to the application field of the deep-ultraviolet optical technology, and aims at solving the problems of the deep-ultraviolet optical film in the prior art that an optical film system is large in absorption loss by adopting a total oxide film layer and is large in scattering loss by adopting a total fluoride film layer. The low-loss deep-ultraviolet multilayer film production method includes the following steps: 1 an optical substrate needing film plating is subjected to ultrasonic cleaning, slow pulling and dewatering and N2 drying; 2 an oxide film layer stack is prepared on the optical substrate obtained in the step 1 by aid of the ion assisted electron beam evaporation technology according to a film system structure of the film design; and 3 a fluoride film layer stack is prepared on the oxide film layer stack by aid of the thermal evaporation process. The low-loss deep-ultraviolet multilayer film production method overcomes shortcomings of the loose interior structure and large surface roughness of films in a total fluoride multilayer film system and the shortcoming of large absorption loss of a total oxide multilayer film system caused by acting of middle-and-outer-layer oxide films and laser.

The invention discloses a multilayer-film filling type composite medium nanometer period grating structure and a manufacturing method of the multilayer-film filling type composite medium nanometer period grating structure. The multilayer-film filling type composite medium nanometer period grating structure is composed of a one-dimensional periodicity multi-layer film structure formed by medium gratings in a compounded mode, the duty ratio of the medium gratings is 1:1, and the period of the medium gratings is 100 nanometers to 1 micrometer. Medium materials with the refraction index different from the refraction index of the medium gratings and the heights same as the heights of the medium gratings are deposited at the positions of gaps of the concave portions of the medium gratings, and the multi-layer film structure is composed of two different kinds of medium materials in an alternative mode. The manufacturing method includes the main steps that (1) an ion beam assists an electron beam evaporating coating technology to manufacture a periodicity multi-layer film photonic crystal on the substrate, and (2) the nanometer coining technology, the reaction ion etching process and the electron beam evaporation coating and lifting-away technology are used for manufacturing the one-dimensional filling type composite medium on the medium multilayer films. The manufacturing method of the multiplayer-film filling type composite medium nanometer period grating structure is convenient to use and reliable. According to the filling type composite medium nanometer period grating structure, spectrum sidebands can be effectively restrained, the transmissivity or the reflection rate of a mode guiding resonant filter is improved, and the performance of the mode guiding resonance filter is improved.

A method of making an organic vertical cavity laser array device includes providing a substrate and a bottom dielectric stack reflective to light over a predetermined range of wavelengths and being disposed over the substrate; forming an etched region in the top surface of the bottom dielectric stack to define an array of spaced laser pixels which have higher reflectance than the interpixel regions so that the array emits laser light; and forming a planarization layer over the etched bottom dielectric stack. The method also includes forming an active region over the planarization layer for producing laser light; and forming a top dielectric stack spaced from the bottom dielectric stack and reflective to light over a predetermined range of wavelengths.

The invention discloses a Ka-band standing wave type series-fed microstrip line array antenna, a Ka-band standing wave type series-fed microstrip area array antenna and manufacturing methods thereof.The microstrip line array antenna comprises a dielectric substrate, a ground layer, a main feed line, a feed line and a series-fed microstrip line array. The main feed line and the series-fed microstrip line array are both connected to the upper surface of the dielectric substrate. The ground layer is connected to the lower surface of the dielectric substrate. The series-fed microstrip line arraycomprises a first impedance transform matcher and a plurality of array elements. The microstrip area array antenna includes a dielectric substrate, a ground layer, a main feed line, a plurality of second impedance transform matchers, and a plurality of series-fed microstrip line arrays. The main feed line, the plurality of second impedance transform matchers and the plurality of series-fed microstrip line arrays are all connected to the upper surface of the dielectric substrate. The ground layer is connected to the lower surface of the dielectric substrate. One end of the series-fed microstripline array is open-circuited, and the other end of the series-fed microstrip line array is connected to the main feed line through the second impedance transform matchers. The incident wave and the reflected wave are superimposed on the main feed line to realize standing wave transmission. The antenna structure is simplified by using the compact structure and simple design of the series-fed network.

The invention relates to an optical waveguide mode converter used for improving an optical waveguide transmission characteristic. The converter comprises a single-mode optical fiber, a segment of coreless optical fiber with a ball lens and a rectangular optical waveguide. The end surface of the single-mode optical fiber is connected to one segment of coreless optical fiber with the ball lens. A segment of effective distance is kept between an optical waveguide end surface and the ball lens. The axis center of the single-mode optical fiber, the axis center of the coreless optical fiber and theaxis center of the optical waveguide are kept at a same horizontal straight line. Through the mode converter, the single-mode optical fiber can be converted to output a Gaussian light beam, and lightenergy is almost coupled to an optical waveguide base model so that an optical waveguide mode conversion function is reached; and optical waveguide scattering losses and mode crosstalk are reduced, and communication quality is increased.

The invention discloses a slow wave structure based on a semiconductor-filled metal waveguide structure. The slow wave structure comprises a uniform metal hollow waveguide pipe wall, an air gap and a conical filled high-refractive index semiconductor medium strip. In the slow wave structure, by utilizing the abnormal characteristic that the direction of energy flow in the air gap is opposite to that of energy flow in media when electromagnetic waves are transmitted in a high-refractive index semiconductor-filled waveguide structure and selecting parameters of the waveguide structure reasonably, the average energy flow of the electromagnetic waves with different frequencies in air and the average energy flow of the electromagnetic waves with different frequencies in a semiconductor at the corresponding position of waveguide are approximate, so the electromagnetic waves have extremely low group velocity. When the electromagnetic waves enter a port and are transmitted along the waveguide, the group velocity of the electromagnetic waves is reduced gradually, and the energy of the electromagnetic waves is enhanced gradually until the electromagnetic waves reach specific parts corresponding to the frequencies; and waveguide parts in which the electromagnetic waves with the different frequencies can reach are different from one another, so the frequency division, field restriction and reinforcing effects of the electromagnetic waves are realized simultaneously by the structure.

A method for manufacturing a graphene gain coupling distributive feedback type silica based mixing laser. The method comprises the following steps of manufacturing silicon waveguides on top silicon of an SOI slice; manufacturing a graphene district grating on the SOI slice subjected to the manufacture of the silicon waveguides to form a chip; performing metal stripping to obtain the SOI part before bonding; sequentially growing a lower separation limit layer, an active area and an upper separation limit layer on a substrate in an epitaxial mode to form an epitaxial wafer; etching ridge waveguides; forming a layer of metal in an evaporation mode, and performing metal stripping to obtain an optical coupling window and a metal electrode; thinning the substrate and manufacturing a back metal electrode; performing metal bonding by means of selected districts to finishing manufacture. The method is simple in process, low in scattering loss and good in single-mode effect and has pure gains.

The invention discloses yttrium aluminum garnet (YAG) powder without a sintering aid, yttrium aluminum garnet ceramic as well as a preparation method and application thereof. The YAG powder is prepared from (RExY1-x)3Al5O12, a binder and a dispersing agent according to a mass ratio of 100: (0.1-1.0): (0.1-1.0); wherein x is equal to 0-1, and RE represents rare earth elements. YAG powder is calcined and subjected to cold isostatic pressing to obtain a ceramic biscuit, the biscuit is placed in a mold and subjected to spark plasma sintering or scintillation sintering, the ceramic is polished, andthe yttrium aluminum garnet transparent ceramic can be obtained. A sintering aid is not required to be added into the ceramic, YAG is completely compact, a grain boundary is free of heterogeneous precipitation, the grain boundary is clean, a grain boundary layer is very thin, the scattering loss of the ceramic can be remarkably reduced, and the linear transmittance of a near-infrared band reachesa theoretical value through a pressure and high-voltage multi-field coupling sintering mode.