Study On Semiconductor Photonic Integrated Device Based Millimeter-Wave Heterodyning Source

Optical generation of high-frequency millimeter-wave (mm-wave) is a key technology for radio over fiber (RoF) system, which has attracted much attention in recent years. Compared with traditional electronic methods, generation of mm-wave by optical means is not only able to reduce the system cost, but also capable to realize wide-range frequency tunability. Meanwhile, the technology also has wide applications in the fields of radar, missile guidance, remote sensing and so on. By monolithically integrating the optical mm-wave generation system, the complexity and cost of the system will be further reduced, as well as improving its performance and practicability.In this dissertation, an integrated heterodyning light source based on sideband injection locking is designed and fabricated, and its performance in optical microwave generation is investigated systematically. Factors that influence the phase noise performance of the optically generated microwave carrier in a sideband injection locking system are also analyzed in detail. It is experimentally verified that monolithically integrated device is effective in reducing the complexity of optical microwave generation system and improving the phase noise characteristics of the generated microwave signal.The performance of sideband injection locking system based on discrete lasers is studied first. The phase noise performance of microwave carriers generated by single- and double-sideband injection locking schemes is compared. Microwave carrier at 42 GHz with low phase noise is also generated by adopting high-order sideband injection locking. The influence of the coherence of the sideband injection locking system on the phase noise performance of the generated microwave carrier is then investigated. The lineshape of master laser and the optical path length difference between the two beating lights are found to be critical to the phase noise performance of the optically generated microwave. And it is further pointed out that monolithic integration is an efficient way to improve the phase noise performance of the sideband injection locking system.An AlGaInAs multiple quantum well Y-branch integrated dual wavelength laser diode is then designed and fabricated, which monolithically integrates two DFB lasers with associated Y-branch coupler. Both external and self injection locking configurations are adopted to generate high-frequency millimeter-wave carrier by the integrated dual wavelength laser diode. In the external injection locking configuration, the integrated device is used in place of two discrete slave lasers and the optical path difference between the two beating lights is thus made negligible. In the self injection locking configuration, one DFB laser works as the master laser and the other one works as the slave laser. By directly modulating the master laser near its relaxation resonance frequency, multiple sidebands are generated due to enhanced modulation nonlinearity. As a result, frequency multiplication can be realized by means of single-sideband injection locking. In both external and self injection locking configurations, millimeter-wave carrier at a frequency over 40 GHz has been generated and the phase noise performance improves remarkably compared with system based on discrete lasers. In addition, a frequency tuning range on the order of GHz has also been demonstrated for the optically generated millimeter-wave carrier.