Analysis of a spatially dispersive displacement sensor utilizing an AlGaInP chip.

We present a demonstration and analysis of an industrialized design of a spatially dispersive displacement sensor, which is composed of an AlGaInP gain chip in visible range, optical assembly, and a spectrum analyzer. The sensor utilizes the spatial dispersion of focus from the optical assembly and wavelength spectrum's deviation induced by the displacement of the target. As a result, the sensor delivers a quick and simple way of measuring displacement. By adapting the magnification and resolution of the optical assembly, a displacement sensor with a middle measurement range, ~10 microm, was obtained. However, we should note that 25 nm resolution is limited by the bandwidth and temperature fluctuation of the gain chip.