213 nm laser written waveguides in Ge-doped planar silica without hydrogen loading

Opt Express. 2020 Oct 12;28(21):32165-32172. doi: 10.1364/OE.402762.

Abstract

In this paper we present the first example of waveguides fabricated by UV writing in non-hydrogen loaded Ge-doped planar silica with 213 nm light. Single mode waveguides were fabricated and the numerical apertures and mode field diameters were measured for a range of writing fluences. A peak index change of 5.3 x 10-3 was inferred for the waveguide written with 70 kJ cm-2. The refractive index change is sufficient to match the index structure of standard optical fiber. Uniformity of the written structures was measured and a propagation loss of 0.39 ± 0.03 dB cm-1 was determined through cutback measurements.