Stimulated Raman Scattering (SRS) in α‐AlOOH (Diaspore)

Abstract

In single crystals of orthorhombic 𝜶-AlOOH, known also as mineral diaspore, 𝝌 (3) -nonlinear lasing by stimulated Raman scattering (SRS) and Raman-induced four-wave mixing (RFWM) is investigated. Picosecond pumping at 1.064 μm wavelength produces a broadband Stokes and anti-Stokes frequency comb with up to 25 SRS-and RFWM-generated emission lines. All observed Stokes and anti-Stokes lasing components in the visible and near-IR are identified and attributed to a single SRS-promoting vibration mode with 𝝎 SRS ≈ 445 cm −1 . The first Stokes steady-state Raman gain coefficient in the visible spectral range is estimated to a value not less than 0.36 cm GW −1 .