Three-dimensional mid-infrared photonic circuits in chalcogenide glass

TL;DR

This paper demonstrates the fabrication of 3D mid-infrared photonic circuits in chalcogenide glasses using direct laser writing, enabling high-visibility interference across a broad wavelength range for applications like astrophotonics.

Contribution

It introduces a novel direct laser writing technique for creating 3D mid-infrared photonic circuits in chalcogenide glasses, covering the entire transparency range.

Findings

Achieved 99.89% interference visibility at 10.6 μm

Demonstrated ultrahigh bandwidth interference from 3 to 11 μm

Fabricated a functional three-beam combiner prototype

Abstract

We report the fabrication of single mode buried channel waveguides for the whole mid-infrared transparency range of chalcogenide sulphide glasses by means of direct laser writing. We have explored the potential of this technology by fabricating a prototype three-dimensional three-beam combiner for future application in stellar interferometry, which delivers a monochromatic interference visibility of 99.89% at 10.6 \mum, and an ultrahigh bandwidth (3-11 \mum) interference visibility of 21.3%. These results demonstrate that it is possible to harness the whole transparency range offered by chalcogenide glasses on a single on-chip instrument by means of direct laser writing, a finding that may be of key significance in future technologies such as astrophotonics and biochemical sensing.