An Optical Millimeter-Wave Generator Using Optical Higher Order Sideband Injection Locking in a Fabry–Pérot Laser Diode

We proposed an optical millimeter-wave generator using a directly modulated optical injection-locked Fabry-Pérot laser diode (FP-LD). In the proposed scheme, one of the higher order sidebands of the master laser light, which is generated by modulation of the bias current of the slave FP-LD, is used to injection-lock one of the FP-LD cavity modes. Low-phase noise millimeter wave is generated through the beating of the injection-locked FP-LD output and the injected master laser light. The proposed scheme does not require an external modulator, high-bandwidth devices, strong external optical injection power, or an additional optical filter. The effects of the choice of lower or upper sideband for injection locking, optical injection power, and amplitudes of the ac and dc components of the bias current on the proposed optical millimeter-wave generation scheme are studied. An experimental testbed is also built to realize the proposed optical millimeter-wave generation and its distribution in radio-over-fiber systems.