Coaxial Packaged DFB Laser With The Thermoelectric Refrigerator Unite

As the development of the science and technology, the optical fiber communication has become one of the key pillars of modern communication and has replaced the traditional telecommunication in many areas gradually. It has large transmission capacity, high speed and anti-electromagnetic interference. So widely used in military, aerospace, and computer network, etc.This paper introduces the technology of optical fiber communication firstly. We know that optical transmitter is an important part of optical fiber communication system. It has the great significance to design and optimize the light emitter which has the good performance. In order to achieve the high speed, long distance and low cost transmission of optical fiber communication system.Semiconductor laser as the most common light source, which is the core component of light emitter in the communication system. Therefore, this paper introduces several kinds of semiconductor lasers. In contrast, distributed feedback (DFB) laser has dynamic single-mode, fast speed, low cost. If we can control its temperature, it will have high application value.The research emphasis of this paper is to design a low cost DFB laser emitter which has a temperature control system. So in this paper, the thermoelectric refrigerator unit was introduced into the coaxial package structural DFB laser transmitter to control the working temperature accurately. At the same time, a heat sink block was used as a thermal transition piece to realize the transmission of light path. This kind of laser transmitter has small volume, low cost, output wavelength stability and some other advantages, which can achieve the high speed and long-distance transmission.The thermal resistance tester, eye diagram tester and SFP module were used to analysis the working temperature, eye diagram and transmission distance of this DFB laser emitter. On this basis, optimizing the optical path and the matching degree between the different devices in order to obtain the better transmission performance, when the laser drive current is 65mA, the laser temperature can be kept in 40℃ stably under the 75℃ environment. At the same time, the transmission distance of the signal can reach to 40 kilometers. So this result has the great significance to achieve high speed, long distance and low cost transmission.