NONLINEAR FREQUENCY CONVERSION BY RAMAN COHERENCE PREPARED IN SOLID HYDROGEN FILM

Abstract

We investigated the Raman coherence characteristics in the solid hydrogen film deposited on a sapphire substrate. By using Raman coherence prepared with two single-frequency pulsed lasers, we generated the multiorder coherent Raman sidebands in solid hydrogen film. High-order Raman sidebands were obtained under strong pumping conditions (≥230 MW/cm2). The generated anti-Stokes(AS)–Raman sidebands extended from ultraviolet (292 nm for AS5 band) to visible (565 nm for AS1 band) region. The multiorder Raman sideband generation is thought to be due to the parametric coupling of pump and coupling lasers. The frequency conversion efficiency shows the maximum (14%) at the pumping intensity of 360 MW/cm2. From the experiment that makes the multimode probe beam beat with the prepared Raman coherence, we found that the prepared Raman coherence replicates the probe beam to its Raman sidebands.