All-Optical Spatial Self-Phase and Cross Phase Modulation Using an NLO Active Pyrylium Dye towards an Optical OR Gate

Abstract

All-optical modulation and optical switching with nonlinear materials are integral parts of the advancing all-optical communication network. This report discusses the synthesis of a promising pyrylium dye, pyrylium-NH2 for NLO based applications and probes its spatial self-phase and cross phase modulation (XPM) properties. This dye can be effectively used for all-optical modulation and OR logic gate operation. A 532 nm DPSS laser of tunable power is used to study the intensity dependent nonlinear refractive indices (n2) of the dye in ethanol, methanol and acetone. The dye has shown significant n2 compared to the existing literature. Concentration dependence, incident intensity dependence and temporal evolution of the far field diffraction annuli rings in these three solvents were studied. The all-optical modulation of a weak signal beam is demonstrated using a high intensity pump beam via cross phase modulation, paving the way to optical switching applications.