All-optical conditional logic with a nonlinear photonic crystal nanocavity

TL;DR

This paper demonstrates tunable, nonlinear optical interactions within a photonic crystal nanocavity, enabling all-optical conditional logic through frequency conversion and nonlinear mixing of resonant modes.

Contribution

It introduces a novel InP-based photonic crystal nanocavity supporting dual modes for nonlinear mixing, enabling all-optical logic operations in integrated circuits.

Findings

Resonant excitation of two localized modes near 1550 nm.

Observation of sum-frequency generation from nonlinear mixing.

Potential for minimally-invasive cavity state monitoring.

Abstract

We demonstrate tunable frequency-converted light mediated by a chi-(2) nonlinear photonic crystal nanocavity. The wavelength-scale InP-based cavity supports two closely-spaced localized modes near 1550 nm which are resonantly excited by a 130 fs laser pulse. The cavity is simultaneously irradiated with a non-resonant probe beam, giving rise to rich second-order scattering spectra reflecting nonlinear mixing of the different resonant and non-resonant components. In particular, we highlight the radiation at the sum frequencies of the probe beam and the respective cavity modes. This would be a useful, minimally-invasive monitor of the joint occupancy state of multiple cavities in an integrated optical circuit.