Stimulated Raman Scattering in ?-Al2O3 Leucosapphire Single Crystals at Room Temperature

Orthorhombic YAlO3 – a novel many‐phonon SRS‐active crystal

“…Another object of the study was to identify SRS‐promoting phonon modes and the activity of χ (3) ‐nonlinear processes in the crystal. It is desirable to point out that similar problems were studied earlier for trigonal α‐Al 2 O 3 (leucosapphire or corundum) , for cubic Y 3 Al 5 O 12 (garnet) and Y 2 O 3 (sesquioxide crystalline ceramic) that also belong to the binary system Y 2 O 3 ‐Al 2 O 3 . As orthorhombic YAlO 3 , all these crystals are widely used as host‐materials for Ln 3+ ‐ and transition‐metal lasant ions (see, e.g.…”

“…For the excitation of χ (3) ‐nonlinear interactions in orthorhombic YAlO 3 single crystals we used our single‐pass room‐temperature SRS‐setup based on a Xe‐flashlamp pumped mode‐locked Nd 3+ :Y 3 Al 5 O 12 picosecond laser, as employed for previous investigations (see, e.g. ). The pump systems includes a two‐stage amplifier and an external KDP frequency doubler, thus providing pulsed emission of up to 20 mJ at either λ f1 = 1.06415 μm wavelength (with pulse duration τ f1 ≈ 80 ps) or λ f2 = 0.53207 μm wavelength (τ f2 ≈ 60 ps).…”

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

“…The spectroscopic investigation of 𝜒 (3) -nonlinear processes in 𝛼-AlOOH was performed using a mode-locked Nd 3+ :Y 3 Al 5 O 12 master oscillator power amplifier system in combination with a spectrometric setup, as described in previous publications (see, e.g., refs. [35,36] ).…”

“…Nonlinear 𝜒 (3) -lasing processes by stimulated Raman scattering (SRS) and Raman-induced four-wave mixing (RFWM) have been studied in a large variety of crystals in the last two decades (for an overview see, e.g., ref. [1]).…”

“…The generated SRS emission lines cover the broad region from ≈0.2 to ≈2 μm and result from SRSactive vibration modes with energies that range between ≈50 DOI: 10.1002/crat.202100055 and ≈3400 cm −1 . The Raman shifts of these SRS-active Raman modes, however, are not distributed equally within the so far realized energy range and there are only few materials, e.g., 𝛼quartz (𝜔 SRS ≈ 465 cm −1 [2] ) and 𝛼-Al 2 O 3 (𝜔 SRS ≈ 419 cm −1 [3,4] ), that possess SRSpromoting vibration modes of around 450 cm −1 . Here, 𝛼-AlOOH, which shows a strong, sharp, and isolated vibration mode at 446 cm −1 in its spontaneous Raman spectra, [5] appears to be a promising further material which could complement the set of SRS materials in this region.…”