Study On The Key Technique Of All Optical Two-dimensional Negative Feedback System

The all optical two-dimensional negative feedback system is an important tool by which low precision optical devices can realize high precision optical image processing. It combines some advantages such as parallelism, ultra-high speed and so on. Combined with affine linear transformation, a real two-dimensional negative feedback image iteration function system (IFS) can be realized. IFS is the core and key technology for fractal and chaotic dynamical system research. An optical two-dimensional negative-feedback system is composed of optical feedback system and adaptive optics calibration system, among which optical feedback system constitutes the all optical closed-loop, to embody the superspeed of the information processing by all optical system. An adaptive optics calibration system realizes the phase adjustment of the light-wave front and then achieve the real two-dimensional negative feedback. This paper designed an all optical two-dimensional negative feedback system, simulated the external character of the wavefront sensor and wavefront correctors realizing the negative feedback, carried out the theoretical derivation and the simulation about the entire optical system, analyzed the performance of the system. The main research contents are as follows:1. Three types of optical feedback systems were analysised and compared, in order to obtain the negative feedback system with the phase information, the coherent feedback were improved, and a type of all optical two-dimensional negative-feedback system is designed, then the system transfer function was derived.2. Some wavefront sensing technology were analyzed, and a Shark Hartmann wavefront sensor was selected as wave detector of this system, then simulations of the external character about the Shark Hartmann wavefront sensor were made with the specific parameters, including Zernike fitting the phase surface, centroid algorithm, and the wavefront reconstruction.3. New liquid crystal wavefront corrector were introduced. Simulations of the spatial light modulator were made with the specific parameters, and the paper proposed an algorithm for phase correction, and used it in a 4f system, the simulation confirmed that the wavefront corrector in the 4f system can improve the imaging quality.4. Combining the adaptive optics calibration system with coherent optical feedback system, an all optical two-dimensional negative feedback system was constructed, and simulations of the system both with open-loop and closed-loop were made, the output image quality variations were analyzed with different input images as well.In this paper, the innovative point is that an adaptive optics calibration system with coherent optical feedback system, an all optical two-dimensional negative feedback system was designed. The system is used to reduce coherent noise, improve the system precision, and lay the foundation for high precision optical computing. The external characters of the wavefront sensor and wavefront corrector with the specific parameters were simulated, and the wavefront corrector was put into the 4f system to correct the aberration and improve the imaging quality.Through theoretical analysis and simulations, the key components and the performance of the all optical two-dimensional negative feedback system were studied. The study could lay the foundation for the IFS which is composed of an all-optical two-dimensional negative feedback system and the affine linear transformation system.