Thermal tapering of ion-exchanged channel guides in glass

Abstract

We demonstrate a simple technique for thermal tapering of ion-exchanged guides in glass. The mode width changed from 2 to 4.7 μm over a 4-mm taper. The fiber-coupled insertion loss was 2.2 dB, compared with 6 dB for untapered guides. Excess loss from propagation in a taper appears to be less than 0.4 dB.