Low loss laser-written channel waveguides in porous silicon

In this paper we present the fabrication and characterization of low loss buried channel waveguides in porous silicon (PS), designed to work around 1.55 μm, and obtained for the first time by direct laser writing. This novel technique, derived from the laser ablation, is a good alternative to the traditional photolithographic process. In fact, owing to the low thermal conductivity of PS, the high temperatures required for the writing are achievable with low power lasers, making the process highly efficient and possible with the standard equipment present in most laboratories