RF signal generation, hopping and switching based on negative wavelength detuning in SMFP-LDs

Abstract

Single Mode Fabry-Perot laser diode (SMFP-LD) has shown significant effects on digital photonics and optical signal processing due to its prominent advantages such as low power consumption, simple structure and easy configuration, and low cost. Recently, the use of SMFP-LDs on RF signal generation has shown its potential in microwave photonics (MWP. In this paper, we discuss the use of SMFP-LDs in MWP for signal generation, hopping and the switching of RF signal. We propose negative wavelength detuning (NWD) injection locking for RF signal generation, illustrating its benefits over positive wavelength detuning (PWD) injection locking in output signal quality and stability. Also, multiinjection locking in a single SMFP-LD is demonstrated to generate multiple RF signals, which are of the different RADAR bands. Then after, the hopping and switching between the generation of microwave, millimeter wave and, simultaneous microwave and millimeter wave using a single SMFP-LD is demonstrated. As a proof of concept for the switching of RF signal, 2 Gbps 16-bit NRZ signal is used as a control signal to switch the generation of RF signals using SMFP-LDs. The switching speed of less than 40 ps is observed. With the modification in the control unit, switching of multiple RF signal generation can be easily obtained using SMFP-LDs, which can be used for re-configurable and flexible microwave photonics system. With the modification on the control signal as a random bit sequence generator, the proposed scheme can be used for the secure military communication besides other conventional application such as radars, 5G communications, RF sensing and detection.