Photonic-based sensing apparatus using displacement tracking of an optical beam in a semiconductor

Abstract

The invention employs a high-resolution semiconductor optical beam position sensor mechanically coupled to an optical beam source by a mechanical linkage which is either elastically deformable (in the case of a vibration sensor or accelerometer) or thermally expandable (in the case of a temperature sensor). The semiconductor optical beam position sensor is a planar semiconductor with a pair of electrodes thereon defining a gap therebetween. The optical beam has a uniform optical density or beam intensity which traverses within the inter-electrode gap. The two electrodes are two rectifying contacts on the surface of the semiconductor irradiated by the laser beam. The short circuit photo-current across the gap will vary in a well-defined manner as the laser spot is scanned to either side of the symmetric position, thus allowing a readout indicative of acceleration or vibration (in the case of an elastically deformable linkage between beam source and sensor) or indicative of temperature (in the case of a thermally expandable linkage between beam source and sensor).

Dependencies are inferred from the claim text.