Inverted-Rib Chalcogenide Waveguides by Solution Process

This paper studies the fabrication and characterization of solution-processed chalcogenide waveguides by a microtrench filling method. In this process, channels are etched on substrates and backfilled with solution-dissolved arsenic sulfide before being annealed. The waveguides are homogeneous in elemental composition and have good mode confinement. Both simulation and experimental measurements confirm a dominant fundamental mode covering 2.5–2.8 μm. We measure an optical loss of 1.87 dB/cm, which to our knowledge is the lowest among solution-processed waveguides.