A novel fiber-tip micro-cavity sensor for high temperature application

A low cost fiber-optic micro-cavity interferometric sensor is presented. The micro-cavity is fabricated at the fiber tip by splicing a silica capillary to a single mode fiber and then heating/melting the capillary to form a microsphere with an internal air cavity. The sensor has small size and good mechanical strength, and may be used for pressure and temperature measurement in high temperature environment.