Realization of all-optical switch and diode via Raman gain process using a Kerr field

摘要

The idea of optical photonic crystal, which is generated using two counter- propagating fields, is revisited to study gain- assisted all- optical switch and diode using Kerr field. Two counterpropagating fields with relative detuning Delta nu generate standing-wave field pattern which interacts with a four-level atomic system. The standing-wave field pattern acts like a static photonic crystal for Delta nu = 0, however, it behaves as a moving photonic crystal for Delta nu not equal 0. The reflection and transmission coefficients are calculated for the case when a weak incident probe pulse propagates through the system. For static photonic crystal, the system acts like an all optical transistor-as a switch-via control of the external Kerr field, such that, when the Kerr field is off (on) the switch is ON (OFF). However, for a moving photonic crystal, the system acts as an all-optical diode via control of the external Kerr field. The advantage of using the gain-assisted model is the fact that the transmission efficiency is high, i.e. almost 100%.