Low-loss fused silica optical waveguide with borosilicate cladding

Abstract

Optical waveguides consisting of a pure fused silica core and borosilicate cladding were produced by using chemical vapor deposition techniques. A typical guide showed an optical attenuation of 7.5 ± 1.5 dB/km, measured at 0.63 μm (He–Ne laser). In one of the guides whose loss spectrum was studied, the attenuation was less than 20 dB/km between 0.55 and 0.86 μm except for the third OH overtone at ∼ 0.72 μm. The lowest loss of this waveguide occurred at 0.80 μm, with other minima at 0.66 and 1.06 μm.