Electrically tunable all-optical diode in a one-dimensional photonic crystal structure.

Abstract

All-optical-diode tunability with externally applied voltage in a one-dimensional photonic crystal structure of arrangement (BA)5/AgLiNbO3Ag/(AB)5(AABB)5 was investigated. It is an asymmetric hybrid Fabry-Perot resonator which is composed of distributed Bragg reflector segments (AB5) containing the linear (B layers) and nonlinear (A layers) optical materials. The LiNbO3, (LNO) sandwiched with two pairs Ag layers, is employed as a defect. The electro-optical (EO) effect and optical nonlinear response (Kerr effect) of LNO is considered. The linear transmittance (LT) spectrum, nonlinear transmission (NT) curves and field distribution, for left to right (L-R) and right to left (R-L) incidents at different applied voltages are graphically illustrated. Results show that with an increase in the applied voltage, L-R and R-L NT curves deflect, amplify, and compress in comparison to zero applied voltage. At negative voltages, due to accumulation of the EO and Kerr effects, variations are more sensitive. The EO effect in LNO causes tunability of the LT spectrum, and the Kerr effect in nonlinear layers dynamically tunes the optical bistability threshold. The results of this study can be useful in designing externally tunable basic elements for optoelectronic devices.