Photon echoes stimulated from an accumulated grating: Theory of generation and detection

Abstract

We present a theoretical description of the generation and detection of photon echoes, stimulated from an accumulated frequency grating in the inhomogeneous distribution. We show that detection of the echoes takes place via interference in the sample between a properly phased and directed probe pulse and the echo polarization. In this description the echo phenomenon emerges as an induced transparency of the sample rather than a burst of coherent radiation. By solving simultaneously the optical Bloch and Maxwell equations, an expression is obtained which correlates quantitatively the echo intensity to the decay parameters, pulse intensity, and the transition moment. As an application of the theory we present results on the intersystem crossing of pentacene in naphthalene at 1.5 K.