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

Two series of glasses compositions, xGeSe 2 -(100-x) As 2 Se 3 (x = 15,42,63,79,94 mol%) and Ge 30 As y Se 70-y (y = 4,10,15,20 mol%), were selected for optimization with a high Brillouin gain coefficient(g B) 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 xGeSe 2 -(100-x) As 2 Se 3 series of glasses, the gradual increase of GeSe 2 , resulted in a significant increase in elastic modulus and longitudinal sound velocity (V L), whereas refractive index(n) and acoustic attenuation(α) decreased rapidly. The decrease in n, and the increase in V L were not conducive to the calculation of the g B. Furthermore, in the Ge 30 As y Se 70-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 g B = 33.77 × 10−11m/W was obtained in Ge 30 As 20 Se 50 at 1550 nm, and this value was ∼2.3 times greater than that obtained in As 2 S 3 (g B = 14.43 × 10−11m/W) and ∼1.6 times greater than that obtained in As 2 Se 3 (g B = 20.89 × 10−11m/W) chalcogenide (ChG) glass. On the basis of Ge 30 As 20 Se 50 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 g B , and broadened the application in Brillouin lasers. [ABSTRACT FROM AUTHOR]