A Fast Algorithm for Phase Grating Preparation by Real Space Method

Based on a definitely integral formula, an expression of calculating atomic potential distribution function U(r) in a unit cell is derived as follows: Making use of this expression to calculate the phase grating in high resolution image simulation can greatly reduce.the calculating time. In this paper, the derivation of the expression is introduced, and then the computer routine is explained in details. Finally the potential projection map of Mg44Rh7 along [001] direction is shown as an illustration. All operations are carried out in real space, so we call the calculation method as the real space method.

Theory and verification of moiréfringes for x-ray three-phase grating interferometer

Dual-phase and three-phase grating x-ray interference is a promising new technique for grating-based x-ray differential phase contrast imaging.Dual-phase grating interferometers have been relatively completely studied and discussed.In this paper,the corresponding imaging fringe formula of the three-phase grating interferometer is provided.At the same time,the similarities and differences between the three-phase grating interferometer and the dual-phase grating interferometer are investigated and verified,and that the three-phase grating interferometer can produce large-period moiréfringes without using the analyzing grating is demonstrated experimentally.Finally,a simple method of designing three-phase grating and multi-grating imaging systems from geometric optics based on the thin-lens theory of gratings is presented.These theoretical formulas and experimental results provide optimization tools for designing three-phase grating interferometer systems.

Dynamic Gain Equalizer Based on the H-PDLC Volume Phase Grating

The structure and Bragg diffraction characteristics of volume phase gratings based on H-PDLC technology are presented, and the principles and simulation aided design of dynamic gain equalizers with the gratings are discussed.

Optical true time-delay for two-dimensional phased array antennas using compact fiber grating prism

A two-dimensional(2D)optical true-time delay(TTD)beam-forming system using a compact fiber grating prism(FGP)for a planar phased array antenna(PAA)is proposed.The optical beam-forming system mainly consists of a TTD unit based on the same compact FGP,one tunable laser for elevation beam steering,and a controlled wavelength converter for azimuth beam steering.A planar PAA using such2D optical TTD unit has advantages such as compactness,low bandwidth requirement for tunable laser sources,and potential for large-scale system implementations.The proof-of-concept experiment results demonstrate the feasibility of the proposed scheme.

The Transplant of Technology of Capacitive Displacement Transducer to Phase Modulation Grating-the Research of the Grating with nm Measuring Resolution

The method rising measuring resolution through reducing pitch of the transducer has brought forward from the basic structure, principle and the corresponding relationship among pitches of capacitive electrodes, period T and phase shift of vv(x,t). But if the traditional technique of PCB made of the transducer is still used, it will meet with difficulties in lead wire. And so the technology transplant from the transducer to grating is presented, the basic principle of the phase modulation grating similar...

Writing Fiber Grating of Different Wavelength Using the Same Phase Mask

Chirped fiber grating was used in dispersion compensator. We tried to use the same phase mask to write fiber grating of different wavelength with two methods to reduce the price of the fiber grating.