Application of slow-light engineered chalcogenide and silicon photonic crystal waveguides for double-dimensional microwave frequency identification

Abstract

Four-wave mixing effect was utilized within short dispersion-engineered slow-light silicon and AMTIR1 chalcogenide photonic crystal waveguides with group velocities of c/33 and c/23, respectively, for simultaneous measurement of frequency and power level of an RF tone over a frequency range of 0.01–80 GHz. In our numerical simulations, we considered the impact of various nonlinear phenomena that affected the system outputs. An FWM conversion efficiency of approximately − 45 dB was achieved for a 10 mW continuous-wave pump and probe in an 80 µm AMTIR1 PhC waveguide. In our system, two orthogonal and independent outputs were generated simultaneously. These independent outputs were achieved using a microwave photonics Hilbert transformer implemented using the transversal filtering approach. Since the process was inherently incoherent, the nonlinearity of the four-wave mixing did not affect the resulting signals orthogonality. The ability to simultaneously identify both the RF frequency and the power level of a microwave signal would make this system a perfect candidate for various applications, such as instantaneous frequency measurement receivers.