Complex optical microcomponents for integrated-optic applications fabricated by laser ablation

Abstract

Complex concatenated channel waveguides and multimode interference devices have been fabricated by laser ablation of silica-on-silicon substrates for the first time to our knowledge. The technique is based on a tightly focused carbon dioxide laser beam that modifies the refractive index of the area sorrounding the optical waveguide; the process is fast (a few seconds) without any subsequent mechanical or chemical treatment, and the writing speed is about 500 times faster than with UV or femtosecond writing. The results are encouraging for prototyping for the development of an optical sixport device, the equivalent of the widely known microwave technique for amplitude and phase measurements.