ABSTRACT:

A continuous-wave diamond Raman laser is demonstrated with an output power of 5.1 W at 1217 nm. This Raman laser is intracavity pumped by a side-pumped Nd:YLF rod laser: a 43-fold brightness enhancement between the Nd:YLF and diamond Raman lasers is observed, with the ${rm M}^{2}$ beam propagation factor of the diamond Raman laser measured to be ${<}{1.2}$. Although higher output powers are demonstrated in a similar configuration using ${rm KGd}({rm WO}_{4})_{2}$ (KGW) as the Raman laser material (6.1 W), the brightness enhancement is much lower (2.5 fold) due to the poorer beam quality of the KGW Raman laser $({rm M}^{2}<6)$. The Raman gain coefficient of single-crystal synthetic diamond at a pump wavelength of 1064-nm is also measured: a maximum value of $21pm 2~{rm cm}/{rm GW}$ is returned compared to $5.7pm 0.5~{rm cm}/{rm GW}$ for KGW at the same wavelength.