Injection locked VCSELs for microwave photonic applications in analog RF links and real time arbitrary waveform generation

In this paper, we show recent results in the use of injection locked vertical cavity semiconductor lasers (VCSELs) as novel modulators and narrowband optical filters that can be exploited for applications relevant to microwave photonics. Specifically, we exploit the phase modulation that is imparted onto the injection locked signal by modulating the current to the VCSEL. Optical filtering is realized by noting that there exists a `locking range´ which determines the amount of optical detuning from the free running VCSEL and the injection seed signal allowed for the injection locked process to work. Using these two salient properties of injection locked VCSELs, we show that one can simultaneously select single components from a frequency comb and realize either modulation or detection functionality. Furthermore, we show how injection locked VCSELs can be used in highly linear RF analog links and how VCSELs can be used with an optical comb to perform real time waveform generation.