Abstract
The HELIOS project is a European funded program which focuses on the development and integration of the different photonic and electronic building block components required to form high performance photonic circuits with a variety of functionality. One of the key photonic building block components central to most photonic applications is the optical modulator which is required to write data onto an optical carrier. Within the project two designs of carrier depletion based phase modulator are under development, together with a means of enhancing the modulation effect using slow wave and ring resonator based structures. In this work modulation results from the two phase shifters are presented along with passive results from related slow wave and resonator structures.