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

Abstract

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.

Anisotropic Raman spectral analysis and laser output based on large-sized scheelite bismuth molybdate tungstate mixed crystals

“…[32][33][34][35][36][37][38][39][40][41][42] Besides, recently, quaternary molybdate or tungstate tellurate, such as BaTeMo 2 O 9 , BaTeW 2 O 9 , Cs 2 TeMo 3 O 12 , have also received enormous attention as novel Raman crystals and efficient laser output have been achieved in these crystals. [43][44][45][46][47][48][49][50][51][52] Bi 2 Mo 2.66 W 0.34 O 12 (BMO) crystallizes in the monoclinic P2 1 /c structure and within the anionic group, the Mo 6+ and W 6+ cations occupy the center sites according to the W 6+ percentages ranging from 2.6-19.5% for different crystallographic sites, respectively. Correspondingly, the coordination of Mo 6+ /W 6+ ions is strongly distorted, resulting in irregular trigonal bipyramid anionic coordination polyhedra with the longest Mo 6+ /W 6+ -O 2− bond length of about 2.2 Å, and the crystal structure can be regarded as distorted scheelite.…”

“…32–42 Besides, recently, quaternary molybdate or tungstate tellurate, such as BaTeMo 2 O 9 , BaTeW 2 O 9 , Cs 2 TeMo 3 O 12 , have also received enormous attention as novel Raman crystals and efficient laser output have been achieved in these crystals. 43–52…”