The Research On Optoelectronic Oscillator

High-quality microwave signal source is the foundation of the microwave application in a wide range of professional fields, such as civil communication, measuring instruments, aerospace, radar, electronic warfare and so on. As a kind of microwave signal sources, optoelectronic oscillator (OEO) has a lot of potential.OEO emerges the oscillation frequency from several MHz to hundreds of GHz with high Q (quality) values up to 1010. And the signal is tunable. One important thing is that the phase noise of the signal has no relationship with the oscillation frequency, which is a unique advantage of OEO comparing with other traditional microwave signal sources.At first, a brief summary of the background and the present research situation of OEO are introduced. And then, threshold conditions of the basic single-loop OEO and theory of phase noise are discussed. Some measures of reducing phase noise are summarized.By researching and analyzing the technology of the basic single-loop OEO, a study on the experiments is completed. Then we complete a study on experiments of dual-loop OEO. In the dual-loop OEO, we use a filter with small bandwidth and a very short optical fiber to reduce the phase noise and system volume.The last part completes a study on phase characteristics of OEO. We analyze the effect to the phase characteristics of OEO caused by the changes of temperature, the length of optical fiber and the frequency of signal.