OPTICAL-GENERATION, DISTRIBUTION, AND CONTROL OF MICROWAVES USING LASER HETERODYNE

Results are presented which demonstrate the optical generation and transmission of a microwave signal by mixing two high-quality optical signals from diode-laser-pumped Nd:YAG ring lasers, resulting in a narrow microwave line width (less than 5 kHz line width at 3 dB and less than —115 dBc/Hz at 300 kHz from line center) and broad microwave tunability (dc to 52 GHz). A III—V semiconductor waveguide with a doping superlattice active region is used to optoelectronically provide 20 dB of amplitude control and up to 5π of phase shift. This approach can be straightforwardly implemented using integrated optics and fiberoptic links for control of phased array antenna elements. © 1990 IEEE