Stimulated On-Axis Photon Echo Modulation in Ruby

Abstract

Four wave interaction of optical fields in solids is a subject of extensive investigations in nonlinear optics, being a valuable spectroscopic tool as well as offering applications¹ in dynamic optical memories and devices transforming optical wavefronts. Stimulated echoes (SE) may be considered as a delayed four wave interaction. In this paper we present studies of optical SE modulation in ruby. Such modulation has been recently observed ^2,3 in solids and, in the case of ruby, only for the magnetic field at an angle with the crystal axis. We describe here, for the first time, studies of the ⁴A₂(−3/2)→Ē(−1/2) (or −3/2→−1/2) transition using a tunable single frequency dye laser. This transition has not been observed before because of the tuning limitations of the CW ruby lasers used thus far ^3,4.