10 results about "Full width at half maximum" patented technology

The invention discloses a single-crystal single-pixel data acquisition and analysis method based on a neutron time-of-flight technology. The method comprises the following steps: carrying out preliminary orientation on a single crystal to be detected; performing a TOF diffraction experiment on the to-be-detected single crystal, and rotating a diffraction spot of a to-be-detected crystal face to a specified position of a detector according to a preliminary orientation result; screening a target pixel according to single-pixel diffraction data on the detector to obtain a target pixel position and a diffraction spectrum thereof; fitting processing is carried out to acquire interplanar spacing and full width at half maximum of a specific diffraction crystal face of each pixel point; dot matrix strain of different target pixels is calculated, an interplanar spacing distribution diagram, a dot matrix strain distribution diagram and a full width at half maximum distribution diagram of specific crystal faces of the target pixels are drawn, and a mismatch degree distribution diagram can also be drawn for single-crystal high-temperature alloy. The method can be used for extracting the microstructure information of different areas in the diffraction volume of the single crystal material, and has important significance for perfecting the design, preparation and production process and service damage evaluation of the single crystal material and prolonging the service life of the material.

The application discloses a LIBS peak searching method, system and device of adaptive window width symmetric zero area transformation, and belongs to the technical field of laser-induced breakdown spectroscopy element analysis technology.The method first deducts a spectral base through an SNIP method and is preprocessed through Savitzky-Golay filtering, then data segments are segmented, a window width is dynamically adjusted in combination with peak resolution, full width at half maximum and horizontal distance at a maximum slope value - a narrow window is used for adjacent peak regions to improve resolution, a wide window is used for noise or single peak regions to enhance noise reduction effect, and finally, symmetric zero area transformation is substituted to complete peak searching.Experiments show that the peak searching accuracy of the method reaches 97.4%, the false detection rate is 1.75%, the comparison error with the NIST database is less than or equal to 0.071 nm, the noise robustness is better than that of a traditional method, adjacent peaks can be accurately identified and noise interference can be suppressed, and the method is suitable for high-precision LIBS element analysis.

Method for manufacturing a three-dimensional object layer by layer (102), comprising the following steps: Step a) a new layer (105) of grains (201) of a metallic material (109) is applied to a substrate (104), wherein the grains (201) have a mean particle size d50=DM, where the mean particle size is determined as a volume-equivalent sphere diameter, with 50 µm ≥ DM ≥ 1 µm, and a mean layer thickness SD of the newly applied layer (105) is at most 1.5*DM, in particular wherein the new layer (105) of grains (201) is applied to a previously produced layer of grains (200) of the substrate (104); Step b) the topography of the substrate (104) is measured, including the position and shape of the individual grains (201) of the new layer (105); In step c) a lighting plan for the new layer (105) is determined from the topography measured in step b) and the desired shape of the three-dimensional object (102); Step d) according to the illumination plan, at least a part of the new layer (105) of grains (201) is locally illuminated with an electron beam (115), wherein the electron beam (115) has a beam diameter ED on the surface of the substrate (104) with ED≤0.3*DM, where the beam diameter is determined via FWHM (=full width at half maximum); wherein the electron beam (115) selectively illuminates one or more parts (202) of an edge (401) of a respective grain (201), thereby fixing the grain (201) on the substrate (104), in particular on grains (200) of a previously produced layer and / or on other grains (201) of the new layer (105), and wherein the respective illuminated grain (201) remains at a temperature below the melting point of the metallic material (109); wherein the preceding steps a) to d) are repeated several times until the three-dimensional object (102) is complete.

The present disclosure relates to the field of optical technologies, and in particular, to a method, apparatus, system, and computer-readable storage medium for measuring transmittance. The method includes: obtaining a first curve of the reflectance of an optical cavity varying with the frequency of light in a first state, and a second curve of the reflectance of the optical cavity varying with the frequency of light in a second state; determining a first value of the optical power attenuation parameter of the optical cavity in the first state according to the full width at half maximum of the first curve; determining a second value of the optical power attenuation parameter of the optical cavity in the second state according to the full width at half maximum of the second curve; obtaining a correlation formula between the reflectance of the optical cavity, the frequency of light, the optical power attenuation parameter of the optical cavity, the coupling efficiency of light and the optical cavity, and the transmittance of the first mirror; and fitting to obtain the value of the transmittance of the first mirror according to the correlation formula, the first curve, the first value, the second curve, and the second value. The present disclosure can more accurately measure the transmittance of the mirror in the optical cavity.

Provided is a wire rod having excellent drawability. In a circular cross section perpendicular to the axial direction of the wire rod, when the average value of the real interlayer spacing at a depth of 0.5 mm from the surface of the wire rod is set as LaveS (nm) and the maximum value of the real interlayer spacing is set as LmaxS (nm), LmaxS / LaveS is 1.70 or less, and in the circular cross section, the average value of the real interlayer spacing at a depth of 0.5 mm from the surface of the wire rod is set as LaveS (nm) and the maximum value of the real interlayer spacing at a depth of 0.5 mm from the surface of the wire rod is set as LmaxS (nm). FWHMc / FWHMs is 1.10-2.00, where FWHMs (nm) is the full width at half maximum of the real interlayer spacing at a depth of 0.5 mm from the surface of the wire rod, and FWHMc (nm) is the full width at half maximum of the real interlayer spacing at the center of the wire rod.

The application discloses a kind of based on TiO2 / SiO2 Composite Cross Structure Dual Polarization Broadband Achromatic Superlens and design method.The superlens includes SiO2 substrate and array arrangement subwavelength composite unit structure.The center of the unit structure is the cross-shaped cylinder of TiO2 material, the four concave corners (i.e. the intersection inner angle area) of the cross-shaped cylinder are filled with SiO2 triangular prism.The longitudinal axis and transverse axis size of the cross-shaped cylinder can be independently valued, global customization is carried out by particle swarm optimization (PSO) algorithm, while releasing maximum parameter freedom degree, excellent orthogonal dual polarization performance consistency is given to the whole lens.The matching error of actual structure and ideal achromatic phase is minimized, and the simulation results show that the superlens realizes stable achromatic focusing in the wide frequency band of 640nm-740nm, the performance is highly consistent in orthogonal polarization state (X polarization and Y polarization), the average focusing efficiency is stable at more than 51%, the maximum focal length relative deviation is only 2.88%, and the full width at half maximum (FWHM) approaches theoretical diffraction limit.The application has wide application prospect in full-color optical imaging, AR / VR micro display and other fields.

A method of manufacturing an optical fiber, including: heating an optical fiber preform and drawing a glass fiber; measuring an outer diameter of the glass fiber as a function of time; transforming the function of time into a function of frequency; in the function of frequency, identifying a first peak due to a first drawing condition and a second peak due to a second drawing condition; and adjusting the second drawing condition so that fn < fm - wm / 2 or fn > fm + wm / 2 when a frequency of the first peak is set as fm, a full width at half maximum of the first peak is set as wm, and a frequency of the second peak is set as fn.

There is provided an AlN monocrystalline substrate having a size with a diameter of 5.08 cm (2 inch) or more and having a two-layer structure composed of a single AlN monocrystalline as a whole, the two-layer structure composed of a first layer and a second layer distinguishable from each other in a thickness direction regarding a full width at half maximum of an XRC. A full width at half maximum of an XRC of a (002) plane of the first layer is 0.005° or more and less than 0.160°; a full width at half maximum of an XRC of a (002) plane of the second layer is 0.03° or more and 0.16° or less; and a ratio of the full width at half maximum of an XRC of a (002) plane of the first layer to that of a (002) plane of the second layer is 0.03 to 0.99.

The present invention aims to provide a mode conversion device and a design method thereof, which can design arbitrary coupling efficiency and full width at half maximum. The present invention is a mode conversion device having a long-period grating in a core of an optical fiber capable of propagating light in at least two propagation modes, characterized in that the long-period grating satisfies a relationship of mathematical formula C1. Wherein, the full width at half maximum FWHM is a wavelength band in which the coupling efficiency is half compared to the coupling efficiency of the mode conversion of the center wavelength, C is the coupling efficiency, L c is the full coupling length, L g is the grating length, Λ is the grating pitch, and Δβ is the difference in propagation constant of the two propagation modes of the center wavelength as a target of mode conversion; [Mathematical formula C1]

A frequency difference selection method for slope-assisted Brillouin optical fiber sensing, comprising the following steps: Step 1, input the amplitude of the external vibration signal, the strain coefficient of the optical fiber, the minimum detectable power of the detector, and the Brillouin gain spectrum of each position point of the optical fiber; Step 2, for the first position point, calculate the set of allowable frequency differences between the pump light and the probe light at this position point; Step 3, repeat Step 2 until the calculations are completed for all position points to obtain a set of sets; Step 4, for the set obtained in Step 3, find the common intersection V; Step 5, arbitrarily select an element from V, which is the frequency difference between the pump light and the probe light. If V is an empty set, it means that under the conditions given in Step 1, there is no suitable frequency difference available for selection. The present invention performs a full scan of the selectable range of the frequency difference between the pump light and the probe light, avoiding the problems of low error tolerance and difficulty in realizing distributed vibration measurement caused by setting the frequency difference between the pump light and the probe light to half of the full width at half maximum of the BGS; using a single value as the frequency difference between the pump light and the probe light, avoiding the problems of increased frequency sweep points and long acquisition time caused by the multi-slope assistance method.