Waveguide fabrication for integrated optics by electron beam irradiation of silica

The electron beam process is used to make a variety of optical waveguides in silica. The process uses beam energies in the vicinity of 25 keV to make monomode through to three-moded slab waveguides from 2 to 7- mu m deep with peak-index variations ranging from 10/sup -3/ to 10/sup -2/. Different types of silica were irradiated and the lowest measured losses were 0.3 dB/cm. It is shown that the major loss process arises from surface imperfections at the air/silica interface. The guides are stable up to 400 degrees C. The results show that the use of electron irradiation to increase the refraction index of silica has considerable potential in the technology of integrated optics.<
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