Abstract
The realisation of a low-loss, highly efficient, singlemode optical phase modulator in SOI is reported. At a wavelength of 1.5 µm the figure of merit for the device, the induced phase shift per volt per millimetre, is greater than 200°/V/mm. To our knowledge, this is the highest reported value to date. In addition, the device drive current (< 10 mA) is thought to be the lowest yet reported.