Novel fabrication techniques for silicon photonics

Abstract

In this paper we report two novel fabrication techniques for silicon photonic circuits and devices. The techniques are sufficiently flexible to enable waveguides and devices to be developed for telecommunications wavelengths or indeed other wavelength ranges due to the inherent high resolution of the fabrication tools. Therefore the techniques are suitable for a wide range of applications. In the paper we discuss the outline fabrication processes, and discuss how they compare to conventional processing. We compare ease of fabrication, as well as the quality of the devices produced in preliminary experimental fabrication results. We also discuss preliminary optical results from fabricated waveguide devices, as measured by conventional means. In these preliminary results we discuss fundamental properties of the waveguides such as loss and spectral characteristics, as it is these fundamental characteristics that will determine the viability of the techniques. Issues such as the origins of the loss are discussed in general terms, as resulting fabrication characteristics such as waveguide surface roughness (and hence loss), or waveguide profile and dimensions may be traded off against cost of production for some applications. We also propose further work that will help to establish the potential of the technique for future applications.