Objective Stimulated Raman scattering (SRS) in the crystalline Raman gain media is a wellestablished technique for extending the spectral coverage of lasers. However, as a thirdorder nonlinear process, the SRS suffers a relatively low nonlinear gain and consequently has a high threshold, specifically when operating in a continuouswave (CW) scheme. The intracavity pump scheme, in which the Raman crystal is located within the fundamental laser cavity, is an effective alternative to achieve efficient CW Raman output with moderate primary pump power because the high circulating fundamental laser power in the cavity generates sufficient Raman gain. To date, the highest CW Stokes output power of endpumped intracavity Raman lasers has been realized with the self -Raman scheme, in which the processes of lasing and SRS take place in one crystal to minimize insertion losses. However, intracavity Raman lasers with separate lasers and Raman gain media have the advantages of a more flexible output wavelength and distributed thermal load, which are helpful for power scaling. This study presents an efficient CW Nd∶YVO 4 /KGW intracavity Raman laser.The output power of the CW Stokes wave at 1177 nm reaches 6.63 W under an incident laser diode (LD) pump power of 36.6 W, with the corresponding optical efficiency being 18.1%.
MethodsThe experimental setup of the CW intracavity Raman laser is shown in Fig. 1. A 15 mm long acut Nd∶YVO 4 crystal and a 20 mm long N p -cut KGW crystal serve as the fundamental laser and Raman gain media, respectively. The LD pump wavelength is
