Generating tunable microwave signals (1- to 25-GHz) by optical mixing

In this work we report the generation of microwave signals using photo-mixing of two laser beams. In this case, one laser beam is single mode and the other one shows a multimode spectrum. Due to spectral separation between the two lasers, microwave signals can be generated and tuned between 1 and 25 GHz, the bandwidth of the generated signal is approximately 2.5 GHz; however, using narrow-band microwave filters, the photo generated signal can provide microwave information carriers for high-speed telecommunication systems.