147 results about "Nonlinear refractive index" patented technology

The invention discloses a fingerprint identification device and a fingerprint identification system. One side of a transparent cover plate is a slope side; a detection light source is arranged on one slope side of the transparent cover plate; when the finger-free control is performed, because the refractive index of the transparent cover plate is greater than the air refractive index, the light which is transmitted to the transparent cover plate from the slope side of the transparent cover plate is fully reflected; and a light intensity is detected by utilizing a photoelectric sensor; when the fingerprint identification device is operated by the finger, the valleys of the fingerprint is not in contact with the transparent cover plate, and the light is fully reflected; the ridges of the fingerprint is in contact with the transparent cover plate; because the refractive index of the transparent cover plate is smaller than the refractive index of the human body, the light is partly refracted and enters into the air and is partly reflected and radiated to the photoelectric sensor, thereby causing the light intensity difference of the reflective light between the valley position and the ridge position is great and thus improving the accuracy of the fingerprint identification device.

The invention relates to technology for simultaneously measuring multi-phase flow particles online through multi-parameter, and aims to provide a method and a device for simultaneously measuring droplet positions, particle sizes and a complex refractive index. The method comprises the following steps of: (1) dividing a highly coherent continuous laser beam into two beams after spatial filtering and collimating beam expansion, wherein one beam radiates particles in a detected flow field region, and the other beam is used as a reference beam; (2) mixing scattered light of a lateral 30-degree to 90-degree region of particles in the detected flow field region and the attenuated reference beam to perform interference so as to form a hologram, storing the hologram in a computer after being recorded by a digital camera through an imaging device; (3) acquiring a series of reconstructed images of the detected particles along the depth direction by utilizing digital reconstruction technology; and (4) identifying the reflective spot and the refractive spot of the particles from the reconstructed images by utilizing digital image processing technology so as to acquire space coordinates and scattered light intensity ratios. Compared with rainbow measurement technology, the measurement method has the advantages that: a light path system of the measurement device is relatively simple and is easy to implement.

In order to create an optical device with a photonic band gap extending in two dimensions and with very uniform properties in any direction and for any polarisation state, to within 1%, air holes are etched within a substrate of low refractive index material such silicon oxynitride or silica glass. The ratio of air hole area to the remainder of the substrate is low, being less than 35%. The air holes define a quasicrystal structure, having twelve fold symmetry, being based on a square-triangle system. In another development, an etched substrate with a regular crystal structure or quasicrystal structure exhibits a non-linear refractive index. Two adjacent areas in such a substrate have different lattice properties, or have defects in the lattices, to create a unidirectional transmission path (diode action). A further beam of light may be used to modulate the transmission path by reason of the non-linear refractive index.

A tunable optical filter for simulating the waveband spectrums of selected substances. The filter includes an optical waveguide with a core material for transmitting light energy and a nominal core refractive index for the core material. Predetermined periodic variations are formed in the core material of the optical waveguide between the input and output ends that alter the core refractive index of the waveguide at the location of the periodic variations. Depending upon the periodic variations, the waveguide produces a predetermined reference waveband spectrum output that matches the waveband spectrum of a selected substance. A modulator is coupled to the waveguide to selectively modulate the periodic variations to intermittently shift the reference waveband spectrum output to fine tune the filter and reduce signal noise. The filter is useful as a reference cell for correlation spectroscopy, DIAL LIDAR, equipment calibration, and other uses where a predetermined or known waveband spectrum is useful or desirable.

There is disclosed an extreme ultraviolet phase shift mask that may be constituted practically by obtaining an appropriate combination of a refractive index with an absorption coefficient, even in the case of a reflection of an extreme ultraviolet radiation. When constituting a phase shift mask (10) having a reflective mask blank with multilayered films (11) that reflects a short ultraviolet light and a first and a second regions (12a) and (12b) formed on the reflective mask blank with multilayered films (11), firstly, with reference to an arbitrary complex refractive index to the extreme ultraviolet radiation and an arbitrary thickness of a film, a phase and a reflectance of a reflected light contained in the extreme ultraviolet radiation based on the above complex refractive index and the above film thickness are specified. Then, each film thickness and each complex refractive index in formative films of the first and the second regions (12a) and (12b) are set based on the specific results of the phase and the reflectance to ensure that the reflected light contained in the exposure light in the first region (12a) and the reflected light contained in the exposure light in the second region (12b) create a prescribed phase difference.

The invention discloses an organic light-emitting display panel, which comprises an array substrate, an organic light-emitting device arranged on the array substrate, and a packaging layer, wherein the organic light-emitting device comprises a plurality of light-emitting pixels; the packaging layer is arranged at one side, departing from the array substrate, of the organic light-emitting device and at least sequentially comprises a first inorganic packaging layer, a first interlayer bonding layer and a first organic packaging layer in the direction of one side, departing from the array substrate, of the packaging layer; the refractive index of the first inorganic packaging layer is n1, the refractive index of the first interlayer bonding layer is n2 and the refractive index of the first organic packaging layer is n3; and the refractive index n2 of the first interlayer bonding layer is gradually reduced in a gradient manner in the direction, toward the first organic packaging layer, ofthe first inorganic packaging layer, the maximal refractive index of the first interlayer bonding layer is n21, the minimal refractive index of the first interlayer bonding layer is n22, n21 is greater than n1 and n22 is smaller than n3, wherein the thickness of the first inorganic packaging layer is 10-100nm. The total reflection phenomenon is improved, the light extraction efficiency is improvedand the interlayer bonding performance is improved.

The invention relates to a real-time observation single-beam dual-mode parameter adjustable Z scanning device and measurement method. The device mainly comprises a parameter modulation part, a data acquisition part and an observation part, wherein in the parameter modulation part, after passing through an adjustable attenuator and an acoustooptical adjustor, laser is transformed into a laser beam with adjustable power pulse and is focalized onto the surface of a sample by lens; in the data acquisition part, emergent light on the back surface of the sample is divided into two beams by a dispersion prism, one beam of light directly enters a detector thus the nonlinear absorption of material is acquired, and the other beam of light enters the other detector by a small aperture of which the center is coaxial with an optical axis thus the nonlinear refraction of the material is acquired; and in the observation part, a cold light source illumination device is additionally arranged on the light path of the device so that the change of points of action can be observed in real time in experiments. The invention is easy to realize, and can acquire the nonlinear absorption rate and the nonlinear refraction rate of materials in different conditions.

The invention discloses a meta material-microcavity composite structure and a preparation method and use thereof. The composite structure, from up to down, successively includes: a three-layer composite structure, from up to down, including meta materials, two-dimensional materials and optical microcavities, wherein the upper layer meta materials is provided with a plurality of resonance units arranged periodically. Pump lights incident into the meta materials to cause a change of a nonlinear refractive index of the two-dimensional materials, and a local field enhancement effect of the meta materials stimulated by the pump lights and a local field enhancement effect of the optical microcavities are together to improve the nonlinear refractive index of the two-dimensional materials to allow the effective refractive index around the meta materials to be changed, thereby a transmission state of that lights through composite structure is changed. According to the invention, the nonlinear refractive index of the materials is improved, the response time is reduced, and all-optical adjustability is enhanced. The production process is simple, available materials are wide, and the composite structure of the invention may be used for the all-optical switches or the sensors.

An optical sensor has a core, a cladding, and an over-layer. In some embodiments the optical sensor also has a sensing layer. The over-layer acts as a sensitivity enhancement layer, with a refractive index larger than that of the cladding layers. A periodic structure, such as a long-period grating (LPG), is formed in the core. A transmission spectrum of the device shows several notches due to the existence of the LPG. A change in the sensing layer's refractive index and/or thickness results in a shift in the notch wavelengths of the LPG. By choosing proper refractive indices and thicknesses of the core, the cladding and the over-layer, the shift in the notch wavelengths can be significantly enhanced.

The invention relates to a method for measuring the complex refractive index of an absorbing medium based on a real refraction angle method. The method specifically includes the following steps that S1, a uniform light wave serves as incident light to vertically enter a vertical side interface of the absorbing medium with wedge-shaped vortex angles in an incident mode through air; S2, the incident light is refracted through a bevel edge interface of the absorbing medium, and the relation between real refraction angles and the complex refractive index of the absorbing medium is established; S3, the uniform light vertically enters the absorbing medium with the wedge-shaped vortex angles defined in the specification from the vertical side interface, and the real refraction angles defined in the specification generated after refraction of the bevel edge interface of the absorbing medium are measured; S4, in combination with the relation, between the real refraction angles and the complex refractive index of the absorbing medium, established in S2 and according to the real refraction angles measured in S3, a real portion and an imagery portion of the absorbing medium are calculated. A light path adopted for the method is simple, the reliability of the calculated result is high, and a made instrument is low in cost.

Disclosed is a phosphate laser neodymium glass which comprises oxides including the compositions of (mol%) P2O5: 55-65; Al2O3: 4-10; MO (M=Mg, Zn): 7-15; R20(R=Li, Na, K): 18-30; R203(R=B, La, Y, Sb, Nd): 2-3. The glass provided by the invention can be used for high-power laser devices.

The invention provides a liquid crystal display device. A liquid crystal panel of the device comprises a first substrate and a second substrate which are arranged oppositely up and down; and the first substrate and the second substrate respectively comprise one of a quantum dot color filter and an optical membrane. According to the liquid crystal display device, the quantum dot color filter and the optical membrane are arranged in different substrates, even the optical membrane has a relatively large refractive index, the interface total reflection is prevented from generating between the quantum dot color filter and the optical membrane, and a light emergence angle gathering outward a normal line due to refraction relationship is prevented, so that the interference of the refractive index of the optical membrane can be effectively eliminated and the display effect of the liquid crystal display device can be improved.

The coherent imaging method of 4f position based on the Michelson's interferometer is the nonlinear refractive method of 4f position coherent imaging measuring medium based on the Michelson's interferometer. It can solves the problem of data treating bother, nonlinear absorption of traditional 4f coherent imaging technology and the small deform range, high request for stability and complex data treating of Mach-Zehnder interference. The method is composed of the processes: one: starting and adjusting the device; two: collecting the image without image; three: collecting the linear image; four: collecting the nonlinear image; five: computing the linear penetrant ratio; six: computing the nonlinear phase movement; seven: computing the third-order nonlinear refraction coefficient.

The invention provides a joint inversion method for metal terahertz-far infrared complex refractive indexes. A far infrared ellipsometer is used for measuring exact solutions of the complex refractive indexes with the wave number range of 262 cm<-1>-7,946 cm<-1>; in combination with a far infrared Fourier spectrograph, reflectivity spectrums of metal within the wave number range are measured; the complex refractive index, close to the terahertz high-frequency end, measured by the ellipsometer is selected as an experiment initial value, index extrapolation parameters are adjusted through the KK relation between the reflection coefficient range and phases till the inversion result and the ellipsometer complex refractive index calibration result meet error requirements, and the complex refractive indexes of the terahertz-far infrared metal are obtained. The accuracy of the inversion result is verified by comparing the inversion result with measured values at the same frequency band of the ellipsometer. According to the method, theories and experiments verify one another, the inversion result is high in reliability, the defect that complex refractive indexes of THz frequency bands are difficult to measure is overcome, and a research basis is provided for terahertz material scattering properties and development of the terahertz radar imaging technology.

The invention discloses a method for inversion of a rough surface complex refractive index based on a refractive index spectrum. The method comprises measuring sample sheet refractive index spectrums of three or more types of different rough surfaces through a Fourier transform spectrometer, measuring an exact solution of a complex refractive index of a polished calibration plate through a far infrared ellipsometer, calculating the surface root-mean-square height of the rough sample sheet through a genetic algorithm, acquiring a linear relationship of the square of the root-mean-square height and the natural logarithm of the refractive index according to Kirchhoff approximation of a Fresnel reflection index, and calculating a refractive index spectrum of a smooth surface through a least square method, wherein the refractive index spectrum is consistent with that of the polished calibration plate. The complex refractive index measured by the ellipsometer is used as an experiment preliminary value, based on a KK theory, the complex refractive index of the material is inversed according to the refractive index spectrum of the smooth surface, and the inversion result is consistent with the measured result of the ellipsometer. The method is suitable for the complex refractive index extraction of sample sheets having rough surfaces, has a wide measurement range, and overcomes the shortcomings such as the complex operation of the experimental system, the limitation of measurement frequency points and rigorous sample processes.

Configurations for in-situ gas detection are provided, and include miniaturized photonic devices, low-optical-loss, guided-wave structures and state-selective adsorption coatings. High quality factor semiconductor resonators have been demonstrated in different configurations, such as micro-disks, micro-rings, micro-toroids, and photonic crystals with the properties of very narrow NIR transmission bands and sensitivity up to 10⁻⁹ (change in complex refractive index). The devices are therefore highly sensitive to changes in optical properties to the device parameters and can be tunable to the absorption of the chemical species of interest. Appropriate coatings applied to the device enhance state-specific molecular detection.

The invention discloses a method for extracting the complex refractive index of a solid sheet based on a terahertz reflectance spectrum. The method comprises the following steps: preparing two solid sheet samples made of the same material, selecting the thin sample as a to-be-measured sample, selecting the thick sample as an auxiliary sample for time-domain signal baseline correction, and measuring the terahertz time-domain reflected signals of both the to-be-measured sample and the auxiliary sample; adopting the difference between the terahertz time-domain reflected signals of the to-be-measured sample and the auxiliary sample as a baseline, and selecting the first and second peaks of the to-be-measured sample as a baseline-corrected reference signal and a baseline-corrected sample signal respectively; conducting compound digital filtering on the baseline-corrected sample signal and the baseline-corrected reference signal separately, so as to remove system echoes and random noise; according to the filtered sample signal and the filtered reference signal, extracting the complex refractive index of the to-be-measured sample in a self-referencing manner.

A waveguide structure according to the invention comprises a core layer (10), having a refractive index n_core, and an array of rods (11) in the core layer having a refractive index n_rods. The refractive indices satisfy the inequality: n_rods>n_core. In a planar waveguide structure buffer (12) and cladding (13) layers are included, having a refractive index n_buffer and n_cladding respectively. The refractive indices then satisfy the inequality: n_rods>n_core>n_cladding and n_buffer. This condition provides greater vertical confinement of the E-field of an optical signal passing through the waveguide. Furthermore, it allows waveguides to be formed of a glassy material having a similar refractive index and core dimensions to that of a fiber. A high refractive index contrast within the photonic crystal region is used while totally eliminating the need for mode conversion to launch light in and out of the waveguide.

The invention discloses far-infrared high-nonlinear Ge-Te-Se chalcogenide glass. The far-infrared high-nonlinear Ge-Te-Se chalcogenide glass has a formula of Ge20TexSe(80-x) and in the formula, x represents a molar fraction and is in a range of 1-70. The Ge-Te-Se chalcogenide glass does not contain toxic As in the traditional chalcogenide glass and can be prepared through a simple and feasible method. Through use of eco-friendly Te in Ge-Te chalcogenide glass, the Ge-Te chalcogenide glass is optimized through high Te polarizability so that the obtained Ge-Te-Se chalcogenide glass has good permeability, a good glass formation capacity and a superhigh nonlinear refractive index. The far-infrared high-nonlinear Ge-Te-Se chalcogenide glass has a nonlinear refractive index n2 of 10<-17> to 10<-16>m<2>/W and the highest nonlinear refractive index of 2.2602*10<-16>m<2>/W. The far-infrared high-nonlinear Ge-Te-Se chalcogenide glass has a wide application range in a far-infrared area.

The invention discloses an optical nonlinear method which is based on the measuring materials of a 4f phase and coherent imaging system. The 4f phase and coherent imaging system divides incident laser into two beams through a beam splitting prism; wherein, one beam comes into a measure optical path as a probe light and is collected by a CCD camera after passing 4f system and the other beam is a reference light and is collected by the same CCD camera after coming into a reference light path; samples are arranged at a Fourier plane of the 4f system of the measure optical path. The invention is characterized in that the reference light path is the 4f system; and the outgoing direction of the reference light path and the outgoing direction of the measure optical path are parallel. The improvement of the reference light path leads the invention to get the distribution situation of an incident pulse space on the incident plane at the same time of getting pulsed laser energy on the samples and to measure the nonlinear refractive index under the condition of the unstable spatial distribution of light spots with the simple optical path, the quick testing speed, the accurate results and the convenient data processing.