High-Performance Photonic Frequency Conversion In Radio Over Fiber System

Wireless communication make people communicate anytime,while optical fiber communication can offer a large bandwidth which is lack in wireless communication.The mutual integration of them has promoted the development of the Radio-Over-Fiber technology. From the direction of the future communication system, the Radio-Over-Fiber technology, which has the advantages of optical fiber communication and wireless communication, is getting widely application. Photonic frequency conversion, which has the advantages of wide bandwidth, high dynamic range, and small volume,can make conversion between various frequency bands, such as the Ka-band microwave signals can be downconversed to IF one-time via a photonic mixer. So it is widely used in Radio-Over-Fiber system.Firstly,the thesis introduces the background and significance of Radio-Over-Fiber system,and the importance of Photonic microwave frequency conversion for the Radio-Over-Fiber system. Then describes the basic principles of Radio-Over-Fiber system and the various factors that affect the performance of the link. Next,the basic system to realize frequency conversion is modeled and emulated. Finally, in order to improve the performance of frequency-conversion link,and also considering the actual problems of cyclical decline in power and intermodulation distortion, A power fading compensation scheme based on Sagnac ring and a frequency conversion scheme based on DPMZM and Directly modulated laser, have been experimentally demonstrated. The scheme based on Sagnac ring can further improve the dynamic range while compensating for the power. The cascaded scheme of Directly modulated lasers and DPMZM, which aims to simplify the link structure, saving system cost,is based on the cascaded scheme is of DPMZM and MZM,.the result shows that it has achieved frequency conversion, at the same time, the dynamic range has also been significantly improved.