All-optical Signal Up-conversion Based On A Directly Modulated DFB Semiconductor Laser And An Optoelectronic Oscillator

Microwave photonics is an interdisciplinary that combine microwave technology and optical technology,which uses the optical method to produce,process and transmit microwave signals with a low loss,light weight,wide bandwidth and anti-electromagnetic interference and so on.And the microwave/millimeter wave signal generation is a very important research field of microwave photonics technology,so how to get a signal with high frequency,low noise and stable performance is very significant.The optoelectric oscillator(OEO),as one of the ideal sources and researched directions,has the characteristics of high frequency and low noise.However,there are also some problems with OEO,such as unstability,mode competition and so on,which needs further study and solution.The main work of this paper is to realize signal upconversion based on an OEO which based on a directly modulated DFB semiconductor laser.The development process and development status of OEO are introduced before realizing OEO signal up-conversion.Then,in the second chapter,we study the optoelectric oscillator theoretically,analyze the starting principle of the optoelectric oscillator and the phase noise of the OEO.Finally,we introduce several solutions to reduce the phase noise,such as using the high quality device,optimizing the link,adjusting the working state of the optodetector and the utility of photodetector array and other methods.Directly modulated DFB semiconductor laser are characterized by high efficiency,OEO based on directly modulated DFB semiconductor laser has the advantages of simple structure and simple integration,which is a great advantage for OEO integration.The downside is that the frequency of OEO is single.In the last chapter,the signal up-conversion based on a directly modulated DFB semiconductor laser and an OEO is realized.The IF signal with 1GHz frequency is directly modulated on the DFB semiconductor laser,and the high-quality LO signal is generated in the OEO,the PolM modulator serves as the mixer of two signals and finally realize up-conversion,the final output signal has a frequency of 10.66 GHz.The experiment also studies the energy consumption of the system and the frequency response of the OEO.It is concluded that the energy consumption and frequency response of the system are independent of the power of the IF signal,and the phase noise of the OEO shows good characteristics.Compared to other optical signal up-conversion schemes,advantages of the structure are followed:1)A directly modulated DFB semiconductor laser has relatively high modulation efficiency and low energy consumption 2)A high-Q value EBPF in OEO ring ensures that the phase noise of the local oscillator signal is not affected by the injected IF signal.3)The combination of PolM and PBS in the system can reduce the dispersion energy compensation.