128 results about "Echelle grating" patented technology

The invention provides a method for manufacturing triangular groove echelon gratings with 90-degree vertex angles. Each triangular groove echelon grating is composed of a silicon grating structure (1), photoresist (3) and a metal film (4). A manufactured grating groove is a triangle with the vertex angle being 90 degrees, so that the diffraction efficiency higher than that of an echelon grating with the vertex angle being not 90 degrees can be achieved. Each grating structure is produced in an obliquely-cut monocrystalline wafer, the shining angles of the gratings are determined by an obliquely-cut angle for cutting each silicon wafer, and gratings with any blazing angles can be manufactured; according to the 90-degree vertex angles, grooves of silicon gratings with the vertex angles being not 90 degrees are filled with photoresist, then photoetching is conducted again, and the original silicon gratings with the vertex angles being not 90 degrees are converted into the triangular groove gratings with the vertex angles being 90 degrees. According to the manufactured grating structure, the shining face of each grating is a smooth monocrystal silicon <111> grate plane, scattering can be effectively lowered, and the diffraction efficiency of each grating is improved. The purpose that all the gratings have high diffraction efficiency on a broadband is achieved according to the fact that using wave bands can choose to be coated with various different reflecting film layers on the surfaces of the gratings.

The invention discloses a light path structure of an echelle grating spectrometer, which belongs to the technical field of light spectrum. The invention aims to provide a light path structure applied to high-resolution wide-spectral-range and full-spectrum direct-reading spectrum analysis. According to the technical solution of the invention, the light path structure comprises a condensing mirror, an incident pinhole, a parabolic collimating lens, an echelle grating, a cross dispersion prism set, a parabolic focusing mirror and a detector; light to be measured is collected by the condensing mirror and enters the light path of a spectrometer through the incident pinhole; an incident light beam is collimated into parallel light beams by the parabolic collimating lens, then after the parallel light beams are processed by the echelle grating and the cross dispersion prism set to generate two-dimensional cross dispersion, then the two-dimensional cross dispersion is imaged to a target surface of the detector by the parabolic focusing mirror, thereby obtaining a two-dimensional dispersing spectral image. The light path structure of an echelle grating spectrometer disclosed by the invention is simple and reliable in structure, has no movable parts, and does not need to carry out multiple scanning.

A tunable optical filter includes a demultiplexing device, such as an arrayed waveguide grating (AWG) or echelle grating, for separating a multiplexed optical signal into a plurality of demultiplexed optical signals. An imaging lens converges the plurality of demultiplexed optical signals to a common point on a tiltable reflector, which for example is a microelectromechanical system (MEMS) mirror. The tiltable reflector is rotated about a first axis to select which one of the demultiplexed optical signals in the plurality the tunable optical filter is tuned to. More specifically, the tiltable reflector is rotated about the first axis to select which one of the demultiplexed optical signals will be reflected with an angle that allows it to repass through the demultiplexing device and be output from an output port of the tunable optical filter.

A spectrometer assembly (10), comprising an Echelle grating (18; 46) for dispersing radiation entering the spectrometer assembly (10) in a main dispersion direction, and a dispersion assembly (16; 40) for dispersing a parallel radiation bundle generated from the radiation entering the spectrometer assembly in a lateral dispersion direction, is characterized in that the dispersion assembly (16; 40) is reflective, and the dispersion assembly (16; 40) is arranged relative to the Echelle grating (18; 46) in such a way that the parallel radiation bundle is reflected in the direction of the Echelle grating. The Echelle grating (18; 46) may be arranged in such a way that the dispersed radiation is reflected back to the dispersion assembly (16; 40).

An optical de-MUX includes a sub-wavelength grating that magnifies an input optical signal. In particular, along a direction perpendicular to a propagation direction of the optical signal, the sub-wavelength grating has a spatially varying effective index of refraction that is larger at a center of the sub-wavelength grating than at an edge of the sub-wavelength grating. Moreover, the optical de-MUX includes an optical device that images and diffracts the optical signal using a reflective geometry, and which provides different diffraction orders to output ports. For example, the optical device may include an echelle grating.

A monolithic receiver photonic integrated circuit (RxPIC) chip includes a plurality of optical signal channels together with other active elements integrated on a semiconductor chip, which chips further include a wavelength selective decombiner comprising a supergrating or an Echelle grating which provides for a more compact chip compared to an integrated on-chip arrayed waveguide grating (AWG) functioning as a wavelength selective decombiner.

The invention relates to a method for adjusting a small echelle grating spectrometer. The method comprises the following steps of: fixedly arranging a first incidence pinhole and enabling laser light of a first visible laser device to be incident into the first incidence pinhole; adjusting the position and the angle of a collimating lens so that the collimating lens works in the optimum state; eliminating rolling errors and pitching errors of a crossed dispersion prism; adjusting the position and the angle of a focus lens so that the focus lens works in the optimum state; arranging and adjusting echelle grating and preliminarily adjusting the incidence angle of the echelle grating; adjusting the position of an image plane of an area-array detector and rolling errors of the image plane; and precisely adjusting the incidence angle of the echelle grating and the incidence angle of the crossed dispersion prism. Required professional auxiliary devices are few, the method is an accurate adjusting method which is simple and convenient to operate and easy to apply, and is beneficial for realizing spectrum analysis, with high resolution, wide spectrum range and a transient full-spectrum direct-reading function, of the echelle grating spectrometer.

The invention provides a debugging method of an echelle grating spectrograph, belonging to the technical field of spectrums. The method comprises the following steps: allocating a laser, a standard light source and a plane mirror for debugging; installing an optical system and detector assemblies of the spectrograph by taking the laser light as reference beam, and replacing the echelle grating by the plane mirror; replacing the standard light source, adjusting the position of the detector according to a spectrum image obtained on the detector to optimize the whole image quality; according to the deviation between an X-directional position of light spots on the spectrum and a spectral line position of an ideal spectrum model, adjusting the placing angle of a reflecting prism unit; replacing the plane mirror by the echelle grating, and adjusting a pitch angle of the echelle grating according to an Y-directional position of the light spots in the spectrum; and comparing the spectrum images of the adjusted detector with the ideal spectrum models, when the spectrum images are similar to the ideal spectrum models, reversely calculating accurate state parameters according to the practical spectrum and adjusting the spectrum models to adapt to the practical images. The method has the advantages that less tools are need and the operation is simple; and furthermore, the debugging operation of the echelle grating spectrograph can be effectively simplified.

The invention relates to a spectrometer arrangement (10) comprising a spectrometer (14) for producing a spectrum of a first wavelength range of radiation from a radiation source on a detector (42). Said arrangement also comprises: an Echelle grating (36) for the spectral decomposition of the radiation penetrating the spectrometer arrangement (10) in a main dispersion direction (46); a dispersing element (34) for separating the degrees by means of spectral decomposition of the radiation in a transversal dispersion direction (48) which forms an angle with the main dispersion direction of the Echelle grating (36), in such a way that a two-dimensional spectrum (50) can be produced with a plurality of separated degrees (52); an imaging optical element (24, 38) for imaging the radiation penetrating through an inlet gap (20) into the spectrometer arrangement (10), in an image plane (40); and a surface detector (42) comprising a two dimensional arrangement of a plurality of detector elements in the image plane (40). The inventive arrangement is characterised in that another spectrometer (12) comprising at least one other dispersing element (64) and another imaging optical element (60,66) is provided in order to produce a spectrum (68) of a second wavelength range of radiation, which is different from the first wavelength range, from a radiation source on the same detector (42). The spectra can be spatially or temporally separated on the detector.

An Echelle grating has alternate first (1a) and second (1b) sets of facets (1). The first set of facets (1a) is operative to reflect incident light (4) for diffraction and the second set of facets (1b) extends between adjacent facets of the first set (1a). Only the first set of facets (1a) is metallized to enhance reflection. The second set of facets (1b) is left unmetallized. This configuration reduces polarization dependent loss (PDL).

An optical receiver is described. Using silicon-photonic components that support a single polarization, the output of an optical receiver is independent of the polarization of an optical signal. In particular, using a polarization-diversity technique, the two orthogonal polarizations in a single-mode optical fiber are split in two and processed independently. For example, the two optical signals may be provided by a polarization-splitting grating coupler. Subsequently, a redistribution element provides mixtures of the two optical signals. Next, a wavelength channel in the two mixed optical signals is selected using a wavelength-selective filter (for example, using ring-resonator drop filters or an echelle grating) and converted into an electrical signal at an optical detector (such as a photodetector) to achieve polarization-independent operation.

An Echelle spectrometer arrangement (10) with internal order separation contains an Echelle grating (34) and a dispersing element (38) for order separation so that a two-dimensional spectrum having a plurality of separate orders (56) can be generated, an imagine optical system (18, 22, 28, 46), a flat-panel detector (16), and predispersion means (20) for predispersing the radiation into the direction of traverse dispersion of the dispersion element (38). The arrangement is characterized in that the predispersion means (20) comprise a predispersion element which is arranged along the optical path behind the inlet spacing (12) inside the spectrometer arrangement. The imaging optical system is designed in such a manner that the predispersed radiation can be imaged onto an additional image plane (24) which does not have any boundaries in the predispersion direction and which is arranged along the optical path between the predispersion element (20) and the echelle grating (34). Optical means (20, 68) in the area of the predispersed spectrum are arranged to influence the spatial and/or the spectral beam density distribution on the detector (16).

The invention provides a dayglow temperature photometer and a method thereof for detecting airglow spectrum intensity and temperature. An echelon grating and a narrow-band interference filter equipped with a micro-angle stepping motor are organically combined to serve as a core device of the dayglow temperature photometer, the high spectral resolution is obtained, the range of spectrum detection is broaden by rotating narrow-band filter, and luminous intensity and temperature of dayglows in an upper atmosphere are detected simultaneously by utilizing a high-resolution spectroscopic method and a rotational spectral-line temperature-measuring method. The dayglow temperature photometer comprises four portions including a light guide system, a telescopic system, a light splitting system and an imaging system which are sequentially arranged.

The invention relates to the field of raman spectrometer, in particular to a medium-stepped grating type spatial heterodyne raman spectrometer optical path structure. Two middle-step gratings (or onemiddle-step grating and one plane reflector) are adopted, and a spatial heterodyne interference effect is generated to realize spatial heterodyne raman spectrum measurement, so that the problems of low measuring efficiency, low resolution and small visual field broadening angle due to the fact that a moving part is generally arranged in a traditional fourier transform raman spectrometer are solved. The use level N of the middle-step grating is larger than 1. Under the condition that the range of the total measuring wave band of the raman spectrum of an optical path remains unchanged, the morethe use level N of the middle-step grating is, the higher the raman spectrum resolution of the optical path structure is. The back scattering raman spectrum of a sample can be measured, and the transmission raman spectrum of the sample can also be measured.

A bidirectional multiplexer and demultiplexer based on a single waveguide grating is presented. In one embodiment of the invention, the device contains a multi/demultiplexer having an echelle grating disposed between a plurality of input channels and a plurality of output channel arrays. The input and output channels are assigned in a particular order, such that the multiplex and demultiplex functions have the same wavelength channels and such that the blaze angle of the grating facets are optimized simultaneously for both the multiplex and demultiplex function. Because the optical signals are multiplexed and demultiplexed by the same dispersive element, problems of mismatching performance introduced by using different optical components are obviated. The input/output waveguides of the dual-function device can be coupled to a single fiber array, thus reducing the packaging cost.