Computer-Controlled K-Band Frequency Synthesizer Using Self- Injection-Locked Phase-Locked Optoelectronic Oscillator: Part 2

摘要

In Part 1, a highly stable computer-controlled K-Band frequency synthesizer is demonstrated using a tunable optoelectronics oscillator (OEO). LabVIEW software control of a modular rack-mountable frequency synthesizer is achieved from 16 to 24 GHz. A narrowband computer-controlled filter is realized using a broadband YIG filter combined with a narrowband, optically-tuned transversal filter. A forced self-injection-locked phase-locked loop (SILPLL) technique is employed to suppress side-modes generated in OEOs, caused by the long fiber delay lines, and further reduce the oscillator phase noise, reaching an estimated 12 fs timing jitter. Computer control of this SILPLL OEO is demonstrated by achieving both linear chirp (FMCW) and pseudo-random frequency hopping. In Part 2, future generations of the forced SILPLL-based OEO are introduced based on integrated optoelectronics. A Si photonics OEO design is presented using an optical phase modulator in place of the conventional optical intensity modulator, by employing a Sagnac loop as a phase modulation (PM) to intensity modulation (IM) convertor. One hundred percent PM sensitivity improvement is achieved by using a 1D photonic crystal superstate to lateral electro-optic (EO) polymer-based PM. A forced SILPLL K-Band synthesizer using this improved PM is modeled with estimated phase noise of-148 dBc/Hz at an offset frequency of 10 kHz from a 20 GHz signal. A compact multi-mode laser is also developed, where forced oscillation achieves a clean intermodal oscillation frequency at X-Band, with a phase noise of -98 dBc/Hz at 10 kHz offset. This can be extended to K-Band.