Low-nonlinearity and low-loss silicon slot waveguides with ALD-grown thin films

We demonstrate low-loss silicon slot waveguides filled with single and dual atomic layer deposited oxide layers. Propagation losses less than 5 dB/cm and 8 dB/cm are achieved for the waveguides with single (Al 2O 3) and double (Al 2O 3-TiO 2) layers, respectively. The devices are fabricated using low-temperature CMOS compatible processes. The geometries allow nonlinearities nearly two orders of magnitude smaller than plain silicon waveguide