Experimental analysis of emission linewidth narrowing in a pulsed KGd(WO ₄) ₂ Raman laser

The linewidth of a KGd(WO ₄) ₂ (KGW) intracavity pumped Raman laser is analyzed experimentally for different configurations of the Raman and pump laser resonators: with narrow and broadband pump emission profiles, with and without linewidth narrowing elements in the Raman laser resonator, with and without injection seeding into the Raman cavity. The benefits of a narrow linewidth pump source in combination with linewidth narrowing elements in the Raman laser cavity for the efficient linewidth narrowing of the Raman laser emission are explained. 20 kW peak-power pulses at 1156 nm with 0.43 cm⁻¹ emission linewidth are demonstrated from an injection seeded KGW Raman laser.