Dual-Wavelength Fiber Lasers for the Optical Generation of Microwave and Terahertz Radiation

This review describes the evolution of dual-wavelength fiber lasers (DWFLs), which provide a simple and cost-effective approach for the optical generation of microwave and terahertz (THz) radiation. The emphasis of this review is to trace the early development of DWFLs, including the issues and limitations faced by the various gain media right to the latest advancements in this field as well as their roles in generating the desired output. This review covers both the simple approaches of narrow-band filters and comb filters for microwave radiation generation, as well as the use of DWFLs with diethylaminosulfurtetrafluoride or LiNbO₃ crystals for generating THz radiation.