33results about How to "High wavelength accuracy" patented technology

An optical sensor diagnostic system utilizes a tunable Vertical Cavity Surface Emitting Laser (VCSEL) that incorporates an integrated MEMS tuning mechanism provides variable wavelength light into an optical fiber with improved wavelength scanning speed and greater simplicity of construction. Sensors, such as Bragg gratings, are disposed along the fiber in the light path. Each sensor reflects or transmits light exhibiting a characteristic amplitude and / or phase feature with respect to wavelength, the wavelength position of which is affected by an environmental stimulus imposed thereon. The light reflected or transmitted through each sensor is mixed with light passed through an optical reference path and then converted to an electrical signal by a simple detector and monitored by ciruitry that applies signal processing to the detected power spectral distribution, by this means providing output signals indicative of the environmental stimulus on each sensor.

In an external cavity wavelength tunable laser device including an external cavity (20) which includes a semiconductor optical amplifier (2) and performs laser oscillation operation by feeding back external light, a wavelength tunable mirror (7) having at least a single-peak reflection spectrum characteristic within a laser wavelength tuning range is placed on one end of the external cavity (20), and a Fabry-Perot mode interval determined by the effective length of the external cavity (20) is not less than 1 / 10 times and not more than 10 times the reflection band full width half maximum of the wavelength tunable mirror (7).

An optical spectrum analyzer measures to-be-measured light while carrying out calibration processing for correcting wavelength information of spectrum data of the to-be-measured light by a wavelength information correction device through a storage device based on the spectrum data of reference light that is obtained by causing the reference light whose wavelength is known to be incident on a tunable wavelength filter from light incident devices at all times together with the to-be-measured light. Since the optical spectrum analyzer can continuously measure the to-be-measured light in a wide wavelength range at high speed while maintaining high wavelength accuracy, it can continuously obtain the spectrum data of the to-be-measured light with high wavelength accuracy even if it is installed in a place in which an environment intensely changes.

A variable-wavelength light source unit for sending output light of an arbitrary wavelength selected in a variable-wavelength light source section 1 has an optical variable attenuator 2 placed on the output side of the variable-wavelength light source section and a control circuit 4 for controlling the attenuation amount of the optical variable attenuator in response to light output provided by splitting a part of the output light.

Provided is a process for producing colloidal crystals from which a large single crystal reduced in lattice defects and unevenness can be easily produced at low cost without fail. The process for colloidal crystal production comprises: preparing a colloidal polycrystal dispersion in which colloidal crystals precipitate at a given temperature (preparation step); introducing into a vessel The colloidal polycrystal dispersion in the state of containing fine colloidal polycrystals precipitated (introduction step); and melting the colloidal polycrystals and then recrystallizing the molten polycrystals (recrystallization step). The crystals thus obtained have fewer lattice defects and less unevenness than the original polycrystals.

The present invention belongs to the technical field of elemental analysis, and more particularly, relates to a dynamic calibration method for echelle spectrometer in laser-induced breakdown spectroscopy, comprising: S1: collecting a standard light source by using an echelle spectrometer; S2: in combination with a calibration function, calculating a pixel position coordinate ({circumflex over (x)},ŷ) corresponding to a spectral wavelength ŵ; S3: performing dynamic searching and filtering near the pixel position coordinate ({circumflex over (x)},ŷ) to obtain a set D of all pixel position coordinates, and adjusting all original intensity values in the set D to obtain intensity values F(Ix,y), and S4: calculating a spectral line intensity value after dynamic calibration by summing the adjusted intensity values F(Ix,y), thereby completing dynamic calibration of the result of the echelle spectrometer. The method in the present invention can overcome the shortcoming, i.e., the existing echelle spectrometer is only calibrated before measurement without solving the spectral line drift during use, increasing the absolute intensity of the wavelength and reducing the detection limit of the quantitative analysis, as well as improving the precision of the quantitative analysis of an element to be analyzed.

The invention provides a method for calibrating the wavelength of an ultraviolet spectrograph. A 532 nanometer base frequency laser device, a frequency stabilization system, a frequency doubling system and a servo control system are mainly used in the method. The whole working process of a device comprises that the laser of the 532 nanometer base frequency laser device is divided into two channels through a light splitting element; one channel of the laser of the 532 nanometer base frequency laser device passes through the frequency stabilization system; the frequency stabilization system provides a stable reference frequency; if the frequency of base frequency laser deviates from the reference frequency, the frequency stabilization system can produce a feedback signal; the feedback signal passes through the servo control system, the cavity length of the base frequency laser device is adjusted, a 532 nanometer base light frequency is ensured to be always equal to the reference frequency provided by the frequency stabilization device, and the stability of a 532 nanometer laser frequency is guaranteed; the other channel of the laser of the 532 nanometer base frequency laser device passes through the frequency doubling system, so that 266 nanometer ultraviolet laser is generated; because the 532 nanometer light base frequency is stable, the frequency of 266 nanometer frequency doubled laser is also kept stable; after passing through an optically coupled system, the 266 nanometer ultraviolet laser enters the ultraviolet spectrograph, and then the ultraviolet spectrograph is calibrated.

The present invention relates to an apparatus and to a method of optical spectrum analysis of an optical spectrum of a light beam (4), comprising the steps of selecting a certain part of the optical spectrum of the light beam (4) to provide a filtered light beam (12), detecting the filtered light beam (12) to provide an electrical signal corresponding to a power amplitude (O(λ)) of the filtered light beam (12), detecting the filtered light beam (12) to provide an electrical signal corresponding to a wavelength of the filtered light beam (12), and providing the power amplitude as a function of the wavelength of the filtered light beam (12).

This invention discloses high precision high power optical fiber coupling laser illumination device, which contains laser driving device for outputting driving voltage and igniting laser, driving device for generating laser lumination power supply, precision temperature control system, environment temperature control system, optical fiber coupler, shaping collimator. Said invention has simple structure and low cost with stable wave length of high precision and stable output power.