34 results about "Coherent diffraction imaging" patented technology

Apparatus and methods for coherent diffractive imaging with arbitrary angle of illumination incidence utilize a method of fast remapping of a detected diffraction intensity pattern from a detector pixel array (initial grid) to a uniform spatial frequency grid (final grid) chosen to allow for FFT on the remapped pattern. This is accomplished by remapping the initial grid to an intermediate grid chosen to result in a final grid that is linear in spatial frequency. The initial grid is remapped (generally by interpolation) to the intermediate grid that is calculated to correspond to the final grid. In general, the initial grid (x,y) is uniform in space, the intermediate grid ({tilde over (x)},{tilde over (y)}) is non-uniform in spatial frequency, and the final grid ({tilde over (f)}x,{tilde over (f)}y) is uniform in spatial frequency.

A method for detect that bottom topography of a phase-type defect of an EUV photolithography mask multilayer film is disclosed. The method includes modeling and detection. In the modeling phase, firstly, the spatial images of blank mask with multilayer phase defects under different illumination conditions are simulated by photolithography simulation software. Fourier transform coherent diffractionimage (FPI) is used to recover that phase of the spatial image, Finally, an artificial neural network is used to establish the detection model, which takes the spatial image information as input andthe mask multilayer phase defect bottom topography parameters as output. In the detection phase, the actual mask space image is collected, and the bottom topography parameters of the actual mask defects are calculated by using the detection model, and the bottom topography of the mask multilayer phase defects is detected. The invention can quickly and accurately detect the topography of the bottomof the phase type defect of the extreme ultraviolet photolithography mask multilayer film.

The invention discloses a single exposure high numerical aperture pulse laser coherent diffractive imaging apparatus and method. The apparatus herein includes a pulse laser 1, an attenuation sheet 2,a polarizer 3, a first lens 4, a diaphragm 5, a sample bench 6, a reflector group 7, a reflector 8 with a hole therein, a light beam collector 9 which are successively and coaxially disposed in the progressing direction of a light beam. The apparatus is provided with a second lens 10, and a liquid nitrogen cooling CCD image sensor 11 which are successively disposed in the progressing direction ofa reflection light beam of the reflector group 7. The reflector 8 with the hole therein is provided with a common CCD image sensor 12 in the progressing direction of the reflection light beam. The liquid nitrogen cooling CCD image sensor 11 and the common CCD image sensor 12 are both in connection to a computer 13. According to the invention, the apparatus herein can simultaneously acquire high angles and central diffraction light spots, and increases 3D reconstruction precision.

The invention discloses a laser complex amplitude measuring method and system based on coherent diffraction imaging. The measuring method comprises the following steps: establishing an optical measuring system, wherein the optical measuring system comprises a laser, an optical attenuation group, an attenuator, a camera and a motorized translation stage; controlling the camera to move to a positionz1 by the motorized translation stage, and acquiring a D1 surface light spot image of the position z1 by the camera so as to acquire a first light spot image; controlling the camera to move to a position z2 at which the light spot size change can be seen clearly by the motorized translation stage, and acquiring a D2 surface light spot image of the position z2 by the camera so as to acquire a second light spot image; calculating an actual wavefront inclination of the laser; calculating complex amplitude of the first light spot image according to the actual wavefront inclination, an objective function and the second light spot image. The measuring method disclosed by the invention is high in sampling resolution and wide in dynamic range, and the laser complex amplitude can be accurately measured.

The invention relates to a method and system for hiding and extracting large-capacity optical information. The hiding method includes: encoding the information to be hidden with a two-dimensional code to obtain a two-dimensional code set; the two-dimensional code set includes a plurality of two-dimensional codes corresponding to the information to be hidden; by including a spatial light modulator A reflective coherent diffraction imaging system, which diffracts the two-dimensional codes in the two-dimensional code set to obtain a set of diffraction patterns; the diffraction pattern includes the diffraction pattern corresponding to each two-dimensional code; obtains the host video; according to the host video , processing the diffraction patterns in the diffraction pattern set to obtain processed images; hiding the processed images in the host video to obtain a video file with hidden information to be transmitted. The invention can improve the security of information transmission.

The invention discloses a wave aberration detecting system with a knife edge as a detection marker and a wave aberration detecting method based on the knife-edge testing technology and the Ptychography technology. The wave aberration detecting system comprises a coherent point light source, a knife-edge graph serving as the detection marker, a detection-marker adjusting displacement platform for fixing the knife-edge graph and a two-dimensional photoelectric sensor. As the wave aberration of a to-be-detected projection lens is detected through the wave aberration detecting system, the system structure can be simplified, the collecting times of an observation surface pattern are decreased, and the detecting speed and the detecting accuracy of the system are increased.

The invention relates to a novel three-step lens-free coherent diffractive imaging method. The method is characterized in that laser beams subjected to collimation and beam expansion are used to illuminate a to-be-measured sample, and recording a diffraction pattern when the front end of CCD has no optical parallels, a diffraction pattern when the front end of the CCD has one optical parallel and a diffraction pattern when the front end of the CCD has two optical parallels; using an algorithm combining wave filtering and coherent diffractive imaging to process the three diffraction patterns, and rebuilding the complex amplitude image of the to-be-measured sample. The novel three-step lens-free coherent diffractive imaging method has the advantages that the bottleneck problem that a traditional coherent diffractive imaging method needs to move the CCD or the to-be-measured sample for multiple times is solved effectively, the problems of random errors during moving and experiment operability are solved at the same time, the method is simple and fast in experiment operation and high in operability, the coherent diffractive imaging algorithm is effectively combined with wave filtering, and convergence rate and a sample recovery effect are increased.

Apparatus and methods for Coherent Diffractive Imaging with multiple, simultaneous, spatially distinct beams chosen and configured to isolate incoherent sums of beam diffraction such that interference between the multiple beams is not present in the data prior to computationally reconstructing the image. This is accomplished through selecting the multiple beams to be non-interfering modes, or through designing the apparatus such that the interference is not recorded, or through processing the collected data to filter the interference before reconstructing the image.

The invention discloses a coherent diffraction imaging method and processing device thereof. The object wave passes through a rotary multi-pinhole plate. The Fraunhofer diffraction intensity distribution pattern of the object wave passing through the multi-pinhole plate is recorded by an image sensor. The diffraction intensity distribution is subjected to inverse Fourier transformation to obtain the correlation function pattern of the recorded object wave, the amplitude and phase information of the object wave to be measured are directly extracted from the points corresponding with each measurement pinhole center position coordinate in the correlation function pattern and the diffraction imaging of the complex amplitude object is realized in the computer. The coherent diffraction imaging method has no need of any iterative process and greatly reduces the requirement of the scanning recording process and positioning accuracy and increases the diffraction imaging speed, with other features of simple processing device, convenient adjustment, lower cost, suitable of various different light source, and the imaging of the complex object or three-dimensional object can be realized without imaging lens, especially suitable for the situation that it is difficult to prepare high-quality X-ray using the imaging lens.