Study On The Key Technique Of Optical2D Negative Feedback System

All-optical two-dimensional negative feedback system can take advantage ofcharacteristics of the light such as parallelism, ultra-high speed, to achieve high-precision optical image processing. In the all-optical two-dimensional negativefeedback system, the negative feedback concept is introduced based on the precisecontrol of the optical wave-front phase. Its major optical closed-loop system isphysically realized. For the design of the phase detection and correction part, theall-optical two-dimensional negative feedback is different from the traditional adaptiveoptics systems. The realization of physical optical closed-loop is researched in thewhole optical system. In all-optical two-dimensional negative feedback system, thephase information in the system is detected and corrected by the wave-front processor inorder to achieve the requirements of the negative feedback system. A suitableamplification part can ensure the system’s high-gain, low-noise requirements. In thispaper, the key techniques of realizing two-dimensional optical negative feedback systemare theoretical analyzed in detail. The optical wave-front detection, optical amplificationtechnology, optical negative feedback system model are researched. In order to realizeall-optical two-dimensional negative feedback system, the wave-front sensor selectionand the system model improvement are researched simulated. The main researchcontents are as follows:1) Comprehensive description of the key technologies of realizing a two-dimensional optical negative feedback system are discussed. It includes the opticalwave-front detection, optical amplification technology and the improved model ofnonlinear closed-loop resonator.2) There are theoretical analyses of the selection of wave-front detector in the keylink of wave-front sensing in the optical negative feedback system link, Proposed a newmeasurement method based on the4f system image spectrum of disturbance todetermine sub-aperture number of Shack Hartmann. By simulation the errors of system,the use of far-field spot roughly determine the spectrum in order to determine thenumber of lens array provides a basis for the selection of the wave-front sensor system.3) Several major optical amplification technologies are reviewed in detail.According to the requirements of optical negative feedback system, the performances ofvarious amplification methods are analyzed and compared and a suitable amplification method is selected for the system.4) Based on the theory of nonlinear optical resonator, the correction and detectiontechniques are used to improve the original system model. The conclusion is derived:The photorefractive variable coefficients of non-linear optical materials are affected bythe input of optical image intensity, which affects the output of the system.