Spontaneous Raman spectra analysis and efficient nanosecond pulse Raman laser of a BaTeW₂O₉ crystal

In this Letter, the spontaneous Raman spectra of a novel, to the best of our knowledge, crystal α-BaTeW₂O₉ (α-BTW) are characterized and analyzed. The relative Raman gain coefficient of the α-BTW crystal is calculated to be 0.84 times that of YVO₄. With a 35-mm-long crystal, the first-order Raman laser of α-BTW operating at 1178 nm is realized. The simple external resonator setup is employed in the first-order Raman laser of α-BTW. The pump source is a lamp-pumped electric-optical Q switched Nd:YAG laser amplifier system operating at 1064 nm with a pulse width of 10 ns. The Raman laser exhibits a threshold of 14.7 MW/cm². In our experiments, a maximum pulse energy of 21.5 mJ is obtained with an optical-to-optical conversion efficiency and slope efficiency of 43.6%, 57.9%, respectively. Due to its high laser damage threshold, relative high Raman gain coefficient, and excellent thermal properties, the α-BTW crystal is a potential Raman material.