The Study Of Optical Fiber Communication Applied To Data Transmission Of Photoelectric Theodolite

In the period of optical communication being one of the chief methods of communication, the aims of using fibers to replace cables to transmit the photoelectric theodolite datas are improving the rate and the quality of data transmission, enlarging the bandwidth, realizing to transmit dates for longer without relay, improving the ability of resist electromagnetic interference. Especially, the optical communication can be used to solve the problem of information leak produced by cables in the national defense system.In order to transmit data successfully, a slip ring is fixed in the vertical axes of the photoelectric theodolite. But, when the signals pass the slip ring, they are interfered by the electromagnetic wave from outer, and they also interfere each other, So that the rate of date transmission and the bandwidth are limited. To these questions, this paper brings forward the project that changing the telecommunications to optical fiber communication. The project is based on the theory of duplexing optical fiber communication with one optical fiber and the characteristic of the light that it can transmit in the air. In this project, a couple of collimators are fixed face to face with the same optical axis to couple the light signal between two optical fibers, so that the data can be transmitted successfully.This paper introduces the theory of optical fiber communication and some correlative devices. It also introduces the circuit designed to transmit video signal. In order to change the electric signal to optical signal and recover to electric signal, the circuit includes analog-to-digital converter, serializer/deserializer, digital-to-analog converter and level translators. In the end of the paper, the result of the feasibility experiment is shown.