Rapid Prototyping of Low‐Loss IR Chalcogenide‐Glass Waveguides by Controlled Remelting

A method for fabricating infrared‐transmitting waveguides that yields low optical losses and strong confinement of light is presented. The method minimises the number of fabrication steps by exploiting the photosensitivity of arsenic trisulfide glass, using it both as a photoresist and as a waveguiding material. Controlled annealing/remelting of the waveguides minimises scattering due to fluctuations in refractive index at the interface between the waveguide and the surrounding medium, allowing low losses to be realised. Bends and Y‐splitter structures have been realised, as well as the longest As₂S₃ serpentine planar waveguides yet reported.