Development of a differential, optical, reflective displacement sensor by use of a multilayered waveguide

A noncontact and compact optical displacement sensor is proposed and demonstrated. The principle of this system is based on the differential optical-fiber displacement sensor [Appl. Opt. 38, 1103 (1999)]. The waveguide of the sensor consists of three thin plate glasses. This approach can miniaturize and lighten the system. The performance of the sensor is geometrically analyzed. The linearity and working range of the sensor are significantly improved compared with those of the optical fiber.