Noise and resolution in IO interferometric sensing

The paper presents a general theory for sensing devices, relating noise and device parame- ters to resolution of modal index changes. The theory is applied to optimise the length of a few integrated optics sensing devices, being a Mach-Zehnder inter- ferometers and two Fabry-Perot implementations. The results enable the determination of the maximum attainable resolution, and show the crucial impor- tance of loss.