Antimony Glasses with Large Nonlinear Refractive Indices, Small Two-Photon Absorption Coefficients and Ultrafast Response at Telecom Wavelengths

Nonlinear (NL) optical properties of antimony oxide based glasses (AG) were characterized for excitation wavelengths from 800 to 1600 m. The NL refractive indices, n
₂
, and the two-photon absorption (TPA) coefficient, ß, have been evaluated using the Z-scan technique. Values of n
₂
≈ 10
^-15
- 10
^-14
cm
²
/W of electronic origin were measured and negligible TPA coefficients (ß < 0.003 cm/GW) were determined. The response time of the nonlinearity is faster than 100 fs as determined using the Kerr shutter technique. The figure-of-merit usually considered for all-optical switching, T = 2 ßλ/n
₂
, indicates that AG are very good materials for ultrafast switches at telecom wavelengths.