Optical sensor with thermal gradient between high-temperature sensor element and conventional lens and fibre

摘要

An optical sensor comprises an optical assembly comprising sensor element 10, spacer 20 and lens 160 arranged consecutively along an optical axis. An optical fibre 30 is coupled to the assembly such that it illuminates the sensor element. The assembly is resiliently mounted in protective housing 140, e.g. by a deformable ring 144, resilient balls or compression spring between housing and spacer, thus insulating it from shock to the housing. The sensor element may be a sapphire pressure- and/or temperature-sensitive pill containing a Fabry-Perot cavity (A, B, C, Fig.2). The spacer may provide a thermal gradient (or shunt) from the sensor element to the lens and fibre. This allows the use of a conventional lens and fibre with a sensor element which is adapted to higher temperatures than them. The sensor is thus suitable for measuring pressure or temperature in high temperature environments (e.g. gas turbines).