Measurement of Raman gain for various crystals by a cavity method

A cavity method has been developed to provide a simple measurement of the Raman gain for various crystals. Formulas for processing experimental results are theoretically justified taking into account the pump pulse duration and the Gaussian beam profile. Under the action of a nanosecond laser with a wavelength of 1064 nm, the Raman gain was measured for a number of crystals: SrMoO$_4$, Sr(MoO$_4$)$_{0.8}$(WO$_4$)$_{0.2}$, Sr$_{0.86}$Ba$_{0.14}$MoO$_4$, Sr$_{0.9}$Ba$_{0.1}$MoO$_4$, and LiNa$_5$Mo$_9$O$_{30}$. For the well-known SrMoO$_4$ Raman crystal, the result obtained is consistent with the literature data (5.6 cm/GW). For SrMoO$_4$-based solid solutions, a decrease in the Raman gain compared to that for SrMoO$_4$ correlates with an increase in the width of the vibrational mode line. For the first time, stimulated Raman scattering was obtained in Sr$_{0.86}$Ba$_{0.14}$MoO$_4$, Sr$_{0.9}$Ba$_{0.1}$MoO$_4$ and LiNa$_5$Mo$_9$O$_{30}$ crystals with the comparable Raman gain of 2.4–2.5 cm/GW under pumping with a wavelength of 1064 nm.