Three-dimensional mid-infrared photonic circuits in chalcogenide glass
  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. 
Airan Rodenas, Guillermo Martin, Brahim Arezki, Nicholas D. Psaila,   Gin Jose, Animesh Jha, Lucas Labadie, Piern Kern, Ajoy...
physics.optics