Silver halide single-mode strip waveguides for the mid-infrared

We report the demonstration of single-mode AgCl(x)Br(1-x) strip waveguides for the mid-infrared (MIR). The waveguides were made by the deposition of AgCl(x)Br(1-x) layers on top of a Si-SiO(2) substrate, followed by photolithographic and lift-off processing. The propagation losses of 20 dB/cm were measured at λ=10.6 μm using the cut-back method. The development of these waveguides is a crucial step toward realizing AgCl(x)Br(1-x) MIR integrated optical circuits, which would be used for applications such as chemical sensing and stellar interferometry.