Reflective optical sensor for long-range and high-resolution displacements

This paper describes a miniature optical displacement sensor with millimetric range and nanometric resolution. This kind of sensor should be integrated in a mesomachine able to make accurate micro/nano-manipulation tasks on wide strokes. This sensor consists of a triangular grating and two fiber optic probes. We introduce the sensor principle and the modeling. The grating is obtained by diamond turning on aluminum alloy. The agreement between simulation and experimental results is very good and the mini-sensor is able to measure a displacement with a 14.9 nm resolution over a 11.8 mm range.