Stimulated vibrational–rotational Raman scattering of hydrogen pumped at a 1064-nm laser

Abstract

A ∼ 2 . 1 - µ m laser is within an atmospheric transmission window and can be used in remote sensing. In this work, a 1064-nm laser was used as the pump source, pressurized hydrogen was used as the Raman active medium, and a dual-wavelength ∼ 2 . 1 - µ m Raman laser was generated. The 2147-nm laser was generated by a combination processes of stimulated vibrational Raman scattering and stimulated rotational Raman scattering, while a 2132-nm laser was generated by stimulated S-branch vibrational Raman scattering. Optimizing experimental conditions yielded a maximum pulse energy of 76.1 mJ, a peak power of ∼ 9.2 M W , and a photon conversion efficiency of 29.8%.

Amplification of Supercontinuum Seed Pulses at ~1078–1355 nm by Cascade Rotational SRS in Compressed Hydrogen

“…Hydrogen has gained popularity due to its largest vibrational shift of 4155 cm −1 and high Raman gain. However, the rotational shifts of 587 cm −1 and 342 cm −1 [14][15][16] for ortho-and para-hydrogen are more attractive for generating optical frequency combs and ultrashort pulses [17]. Nevertheless, the vast majority of studies have focused on the excitation of steady-state SVRS, with conversion efficiencies reaching 68% [18] for nanosecond pump pulses.…”