A 213.4 W continuous-wave diamond Raman laser at 1240 nm with polarization-combined pumping

Abstract We report a record-breaking 213.4 W continuous-wave diamond Raman laser operating at 1240 nm using polarization beam combining dual-fiber pumps and a quasi-Z-shaped cavity to suppress back-reflection. The secondary pump amplified the Stokes field without altering its polarization, confirming polarization-independent gain enhancement. Results demonstrate that high pump power, robust cavity design, reduced optical damage, temperature control of the mirror and crystal and parasitic Brillouin suppression were critical for maximizing Stokes output. The work surpasses the decade-old 154 W record, highlighting diamond’s potential in high-power applications.