Novel broadband travelling wave light intensity modulator

Abstract

The paper analyses the possibility of realising a wideband travelling wave interferomet-ric light intensity modulator (TWILIM) using the conventional simple planar electrode geometry. The proposed modulator with all its three ports matched has an optimum signal feed location which depends upon the microwave optical ‘walkoff’ factor. The ratio (halfwave voltage/ bandwidth), which defines the figure of merit of a modulator, for the proposed modulator, is ¾ that of the conventional end fed TW modulator having identical substrate, electrode length and gap at a given wavelength of operation.