Polarization Modulation Of Parallel Circular Polarization Recorded Grating In Bacteriorhodopsin Induced By Polarized Violet Light And Ronchi Grating Diffraction Based On FDTD Method

In the process of the development of optics, grating is a powerful optical element, widely used in all aspects of laser, spectrograph, integrated optics, optical communication, optical interconnection, optical computing, optical information processing and optical measurement control, has been the focus of the study. In this paper, the diffraction characteristics of bacteriorhodopsin parallel circular polarization recorded grating and phase Ronchi grating was studied.Bacteriorhodopsin(BR) is well-known as a biomolecular photochromic material for its unique optical and photoelectric properties. It is one of the important materials in the field of optical storage, optical signal processing, and photoelectric functional materials. Bacteriorhodopsin’s photoinduced anisotropy makes it become a kind of important material for holographic grating. It is known that diffraction efficiency of non-polarizing grating is independent of the polarization orientation of reconstruction beam; When linearly polarized auxiliary violet light is added, a dependence of diffraction efficiency on polarization orientation of reconstruction beam is induced. In this paper, we built a computation model,based on bacteriorhodopsin simplified two state light cycle model and the Jones matrix, studied the diffraction modulation characteristics of bacteriorhodopsin with polarization grating by this model.Phase Ronchi grating has important applications in aberration measurement Fourier optics, optical system and image quality evaluation etc. So far, Analysis of diffraction characteristics is based on the analytical method mostly. FDTD has been an important numerical simulation method for simulation, and is widely applied to the computation of electromagnetic field, the microstrip antenna, filter etc. This method is being able to simulation of field distribution directly, relatively high accuracy, is one of the methods currently used in numerical simulation of more. In this paper,we used this method to simulation the diffraction process of phase grating Ronchi.In this paper, we completed the following work:1. Research on the basic theory of the finite difference time domain method. Separated by Yee cellular central difference, we derive the finite difference time domain method of the three dimensional finite difference time domain equation.2. Research on numerical dispersion in the Finite-Difference Time-Domain Method. We start from the Courant stability coefficient, the derivation of the time step interval and space interval needs to meet the conditions.3. Polarization modulation of parallel circular polarization recorded grating in bacteriorhodopsin is studied. When linearly polarized auxiliary violet light is added, a dependence of diffraction efficiency on polarization orientation of reconstruction beam is induced. For which, a theoretical model for calculating the diffraction efficiency kinetics of the grating recorded by two parallel circular polarized recording beams is proposed, based on Jones-matrix and photochromic two-state theory. The corresponding experiment is carried out, and the experimental results are consistent with the theoreical analysis.4. Simulation of the process of phase type grating diffraction Ronchi with the finite difference time domain method. The diffraction field of Ronchi grating, which 0 level diffraction light field disappeared, 1 order diffraction light field enhancement had the unique properties, that are analyzed in this paper, and the simulation of the Ronchi grating diffraction field using the finite difference time domain method, the simulation results agree well with the experiment.