Study Of Design And Test Of DFB Semiconductor Lasers Based On Reconstruction Equivalent Chirp Technology

With the rapid development of the information age, the devices connected to the Internet are increasing amazingly, daily transmission of data flows are also in the surge, and smart cities, cloud computing and big data, networking, optical fiber home (FTTH) develop rapidly. All of these raise higher requirements for the bandwidth and transmission speed of the optical communication network. In the face of the issues of large size and large power consumption of discrete optical devices, PICs, integrating different optical devices on the circuit, will be the major trend of the future high speed rate, large capacity optical communication network. DFB semiconductor lasers plays an important role in optical communication network, so it needs DFB semiconductor lasers with good performance. At the same time, most of the communication network is closely related to the common people, so the cost of DFB semiconductor lasers is important in application. Through reconstruction equivalent chirp (REC) technology, the performance of DFB semiconductor lasers can be improved, and the cost can be decreased. Through designing the pattern of sample grating, it can achieve the performance of complicated grating with uniform seed grating. Only the low-cost holographic exposure for uniform grating, and common μm level lithography for the sampled structure are needed in this method. The thesis mainly introduces the design of DFB semiconductor lasers based on reconstruction equivalent chirp technology, and the test of DFB semiconductor lasers.The first chapter introduces the history of optical communication, PICs, the history of semiconductor lasers, the category of semiconductor lasers and the working principle of semiconductor lasers.The second chapter is the base of the study of the design of DFB semiconductor lasers. It introduces the couple mode theory, and the transfer matrix method. We can get the reflection coefficients and time delay with transfer matrix method. In the chapter, it also introduces the principle of reconstruction equivalent chirp technology and equivalent phase shift technology.The third chapter introduces the design of DFB semiconductor lasers to improve single longitudinal mode property by pre-designing bent waveguides and sampling pattern. With this method, the-1st or+1st channel can match well while the 0st channel becomes chaotic. Bent waveguides can solve the difficulty of fabrication non-uniform grating, and decrease the cost of fabrication. We design the multi-wavelength laser arrays and study the loss of bent waveguides. Then we design the new structure to suppress the spatial hole burning effect. Our proposed structure is that there is no index modulation in the middle with equivalent phase shift technology.The fourth chapter introduces the test of the tunable DFB semiconductor lasers with multi electrodes, the test of designed DFB lasers with bent waveguides, SFDR and eye diagram of DFB semiconductor lasers with REC technology.The innovation points of the thesis are as follows:firstly, the design of the structure with pre-designing sampling pattern based on REC technology using bent waveguides can improve the single longitudinal mode property; secondly, the design of the structure with no grating in the middle based on REC technology can achieve suppressing the spatial hole burning effect..