405 results about "Phase grating" patented technology

Electrically controlled volume phase gratings and electrically controlled Bragg Gratings can provide variable diffraction gratings that can be operated in a transmissive and/or reflective mode. They can be made from electro-optic materials placed directly on glass or semiconductor materials, utilizing conventional Liquid Crystal on Silicon (LCOS) processes and equipment. Highly efficient and/or small device form factors may be provided.

The invention discloses an alignment system applied in a lithography device, which uses three periods phase grating with crude precision combination in a substrate marker or a substrate station reference marker, uses a first order diffraction light of the three periods as an alignment signal, simultaneously realizes a big capture range and gets high alignment precision, gets labeled deformation information and other useful information, and through the optimum design of the match and/or the layout of the three periods, the influence on an alignment position by asymmetrical deformation of the marker is effectively reduced.

A device for imaging an object, such as for breast imaging, includes a gantry frame having mounted thereon an x-ray source, a source grating, a holder or other place for the object to be imaged, a phase grating, an analyzer grating, and an x-ray detector. The device images objects by differential-phase-contrast cone-beam computed tomography. A hybrid system includes sources and detectors for both conventional and differential-phase-contrast computed tomography.

A focus/detector system of an X-ray apparatus and a method for generating projective or tomographic phase contrast recordings, are disclosed. In an embodiment of the system, the system includes a beam source equipped with a focus and a focus-side source grating, arranged in the beam path and generates a field of ray-wise coherent X-rays, a grating/detector arrangement having a phase grating and grating lines arranged parallel to the source grating for generating an interference pattern, and a detector having a multiplicity of detector elements arranged flat for measuring the position-dependent radiation intensity behind the phase grating. Finally, the detector elements are formed by a multiplicity of elongate scintillation strips, which are aligned parallel to the grating lines of the phase grating and have a small period, whose integer multiple corresponds to the average large period of the interference pattern which is formed by the phase grating.

A differential phase-contrast X-ray imaging system is provided. Along the direction of X-ray propagation, the basic components are X-ray tube, filter, object platform, X-ray phase grating, and X-ray detector. The system provides: 1) X-ray beam from parallel-arranged source array with good coherence, high energy, and wider angles of divergence with 30-50 degree. 2) The novel X-ray detector adopted in present invention plays dual roles of conventional analyzer grating and conventional detector. The basic structure of the detector includes a set of parallel-arranged linear array X-ray scintillator screens, optical coupling system, an area array detector or parallel-arranged linear array X-ray photoconductive detector. In this case, relative parameters for scintillator screens or photoconductive detector correspond to phase grating and parallel-arranged line source array, which can provide the coherent X-rays with high energy.

A coupling arrangement for allowing multiple wavelengths to be coupled into and out of a relatively thin silicon optical waveguide layer utilizes a diffractive optical element, in the form of a volume phase grating, in combination with a prism coupling structure. The diffractive optical element is formed to comprise a predetermined modulation index sufficient to diffract the various wavelengths through angles associated with improving the coupling efficiency of each wavelength into the silicon waveguide. The diffractive optical element may be formed as a separate element, or formed as an integral part of the coupling facet of the prism coupler.

In a method to determine phase and/or amplitude between interfering, adjacent x-ray beams in a detector pixel in a Talbot interferometer for projective and tomographical x-ray phase contrast imaging and/or x-ray dark field imaging, after an irradiation of the examination subject with at least two coherent or quasi-coherent x-rays, an interference of the at least two coherent or quasi-coherent x-rays with the aid of an irradiated phase grating is generated, and the variation of multiple intensity measurements in temporal succession after an analysis grating is determined in relation to known displacements of one of the gratings or of an x-ray source fashioned like a grating, positioned upstream in the beam path, relative to one of the gratings. The integrating intensity measurements ensue during a relative movement—thus not during the standstill—of one of the upstream gratings or of the x-ray source fashioned like a grating or of the examination subject, with known speed behavior over a final time interval of a final distance.

Embodiments of methods and apparatus are disclosed for obtaining a phase-contrast digital radiographic imaging system and methods for same that can include an x-ray source for radiographic imaging; a beam shaping assembly including a collimator and a source grating, an x-ray grating interferometer including a phase grating, and an analyzer grating; and an x-ray detector, where a single arrangement of the beam shaping assembly, the x-ray grating interferometer and a position of the detector is configured to provide spectral information (e.g. at least two images obtained at different relative beam energies).

The present invention discloses an alignment mark and an alignment signal treatment method used for projection scanning lithography machine based on four-cycle phase grating. The method makes use of a marked coarse grating branch signal for the determination of capture range and position of the coarse alignment, and makes use a marked fine grating branch signal for the determination of the fine alignment position, thereby ensuring the obtainment of high-precision alignment position by only adopting diffraction optical signal of plus or minus 1 grade, improving the alignment efficiency and simplifying the alignment optical system.

An absolute position fiber optic encoder readhead having multiple readhead portions for sensing the displacement of respective scale grating tracks of a scale is disclosed. The detector channels of the readhead portions are fiber optic detector channels having respective phase grating masks. The fiber optic encoder readhead portions are configured to detect the displacement of a self-image of a respective scale grating track of the scale. In various exemplary embodiments, the fiber optic readhead portions are constructed according to various design relationships that provide a relatively high signal-to-noise ratio. Accordingly, high levels of displacement signal interpolation may be achieved, allowing submicrometer displacement measurements. The fiber optic encoder readhead portions may be assembled in a particularly accurate and economical manner and may be provided in a package with dimensions on the order of 1–2 millimeters, resulting in a very small overall absolute readhead dimension that is dependent on the number of readhead portions that are incorporated. Optical fiber receiver channels carrying binary optical signals derived from a scale code track may be provided in the readhead, to provide an extended absolute measurement range.

The invention relates to a structure for a wavelength selection switch composed of a collimator array 1, a beam-expanding prism group 2, a polarization independent transmission phase grating 3, a focusing lens 4 and an MEMS (Micro-electromechanical System) micro-mirror array 5. The volumes of the devices can be reduced by adding a reflector 6 or a steering prism 7 in an optical path. One of the collimator array 1 is used as an input port while the others are used as output ports; DWDM (Dense WaveLength Division Multiplexing) light beams are input and converted to elliptical light beams via the beam-expanding prism group 2, then the light beams with different wavelengths are diffracted to be different deflection angles via the polarization independent transmission phase grating 3, focused by the focusing lens and emitted to different micro-mirrors on the MEMS micro-mirror array 5; each micro-mirror independently controls the reflection direction of every wavelength; the light beams are output to the target output port in the collimator array 1 through the focusing lens 4, the polarization independent transmission phase grating 3 and the beam-expanding prism group 2.