Generation of Microwave Signals by Optical Heterodyning Technique Using a Multimode Laser Diode and a Tunable DFB Laser

This paper reports an alternative to generating microwave signals by using the optical heterodyne technique. The novelty of this work resides in the fact of using a Multimode Laser Diode (MLD) and a tunable Distributed Feedback laser (DFB) instead of a couple of two DFBs. This proposal is demonstrated at the simulation level by using the VPIphotonic software in the frequency range of 0–13 GHz. A Fiber Bragg Grating (FBG) is used as the device that allows the selection of a single optical signal of the MLD. Afterward, this optical signal is beat with the optical signal issued of a tunable DBF allowing in this way the generation of the microwave signals. Even more, the tunability of the microwave signals is controlled by the tunable DBF. Signal-to-Noise Ratio (SNR) parameter is used to evaluate the quality of these microwave signals exhibiting on average a value of 26 dB.