Properties of defects induced by irradiation with a near-infrared femtosecond laser into a series of synthetic fused silicas containing different OH contents are reported. Comparing with the samples before laser irradiation, two absorption bands centered around at 4.8 and 5.8 eV which correspond to E'(≡Si•) center and non-bridging oxygen hole center (NBOHC, ≡Si--O•), respectively, were evidently observed after laser irradiation in high-OH silicas. A photluminescence band with photon energy of 1.9 eV was observed in the as-irradiated silicas under 4.8 eV light excitation. Though no red photoluminescence was observed after irradiated inside low OH-containing silica samples, a similar phenomenon occurs when the laser beam was focused near the surface of low-OH silicas. The induced structures were relaxed after annealing at 400°C. A possible model for the generation of 1.9 eV photoluminescence induced by ultrashort pulse laser in wet silicas and dry silicas was proposed.

Date Published: 14 June 2004
PDF: 8 pages
Proc. SPIE 5350, Optical Components and Materials, (14 June 2004); doi: 10.1117/12.546797

Published in SPIE Proceedings Vol. 5350:
Optical Components and Materials
Michel J. F. Digonnet; Shibin Jiang, Editor(s)