Optical bistability in a silicon nitride waveguide grating

Abstract

Using the Fourier Modal Method for gratings with Kerr media [J. Opt. Soc. Am. B 31, 2371 (2014)] we demonstrate that low energy Optical Bistability for normally incident light field can be observed by strong nonlinear light-matter interactions in a Silicon Nitride waveguide-grating with 2-D periodicity. Finite divergence of the incident light beam has been taken into account in our numerical study and the gratings are designed to observe bistable behavior in direct transmitted light inside the optical telecommunication C-band (1520 nm-1570 nm). The waveguide grating structures are fabricated from PECVD synthesized Silicon Nitride thin film on top of quartz with standard electron beam lithography and reactive ion etching techniques. We aim to demonstrate this phenomenon experimentally using a tunable narrow line-width pulsed laser. Our resonant nanostructures may find applications in free space all-optical information processing and all-optical switching.