Novel Ge-As-Se chalcogenide glass for potential high Brillouin gain coefficient of fiber

Abstract

Two series of glasses compositions, xGeSe2-(100-x) As2Se3 (x = 15,42,63,79,94 mol%) and Ge30AsySe70-y (y = 4,10,15,20 mol%), were selected for optimization with a high Brillouin gain coefficient(gB) by considering both the acousto-optic parameters and the stability of glass against crystallization. The variation in its thermal, mechanical, and material acousto-optic properties were systematically investigated. In the xGeSe2-(100-x) As2Se3 series of glasses, the gradual increase of GeSe2, resulted in a significant increase in elastic modulus and longitudinal sound velocity (VL), whereas refractive index(n) and acoustic attenuation(α) decreased rapidly. The decrease in n, and the increase in VL were not conducive to the calculation of the gB. Furthermore, in the Ge30AsySe70-y series of glasses, n increased to a maximum of 2.62, and α decreased to a minimum of 215 dB/cm/GHz2, with increasing As content. The highest gB = 33.77 × 10−11m/W was obtained in Ge30As20Se50 at 1550 nm, and this value was ∼2.3 times greater than that obtained in As2S3 (gB = 14.43 × 10−11m/W) and ∼1.6 times greater than that obtained in As2Se3 (gB = 20.89 × 10−11m/W) chalcogenide (ChG) glass. On the basis of Ge30As20Se50 host glass, a chalcogenide single-refractive-index fiber was drawn with a lowest optical loss of 0.7 dB/m at 6.5 μm. The above results provided an important reference for the further development of new chalcogenide glass fiber with high gB, and broadened the application in Brillouin lasers.