D. Wiesmann et al., LARGE UV-INDUCED NEGATIVE INDEX CHANGES IN GERMANIUM-FREE NITROGEN-DOPED PLANAR SIO2 WAVE-GUIDES, Electronics Letters, 34(4), 1998, pp. 364-366
Negative refractive index changes of up to 1.7 x 10(-3) have been indu
ced by 248nm excimer laser light in planar germanium-free SiON wavegui
des. Highly temperature-stable 40dB Bragg gratings with a length of 8m
m have been written. A novel mechanism of photosensitisation was used
to create the high-index changes.