Rra. Syms et al., NEAR-INFRARED CHANNEL WAVE-GUIDES FORMED BY ELECTRON-BEAM IRRADIATIONOF SILICA LAYERS ON SILICON SUBSTRATES, Journal of lightwave technology, 12(12), 1994, pp. 2085-2091
Results are presented for channel guides formed by electron beam irrad
iation of silica layers formed on Si substrates by plasma-enhanced che
mical vapor deposition. Electroplating is shown to be a simple method
of fabricating the required surface mask. Optical insertion loss measu
rements performed at 1.525 mu m wavelength show a strong dependence on
the irradiation mask width, charge dose, and electron energy, and par
ameters for low propagation and coupling loss are identified. Optimum
propagation losses are 0.4 dB/cm (TE), 0.75 dB/cm (TM). Spectral loss
measurements are also presented for as-deposited and thermally anneale
d material, and it is shown that beneficial results are obtained by an
nealing before irradiation. The stability of irradiation-induced chang
es is also described.