Ultra-miniature fiber-optic pressure sensor system and method of fabrication

摘要

Ultra-miniature surface-mountable optical pressure sensor is constructed on an optical fiber. The sensor design utilizes an angled fiber tip which steers the optical axis of the optic fiber by 90°. The optical cavity is formed on the sidewall of the optic fiber. The optical cavity may be covered with a polymer-metal composite diaphragm to operate as a pressure transducer, Alternatively, a polymer-filled cavity may be constructed which does not need a reflective diaphragm. The sensor exhibits a sufficient linearity over the broad pressure range with a high sensitivity. The sensitivity of the sensor may he tuned by controlling the thickness of the diaphragm. Methods of batch production of uniform device-to-device optical pressure sensors of co-axial and cross-axial configurations are presented.

主权项

1. A surface-mountable ultra-miniature fiber-optic pressure sensor system, comprising:
at least one sensing head, said at least one sensing head being formed on an optical fiber having an optical guide channel defined within sidewalls and extending between an input end and a tip end of said optical fiber, wherein said tip end of said optical fiber is formed with an end surface angled at a predetermined angle relative to an optical axis of said optical guide channel of said optical fiber, wherein said angled end surface redirects light traveling along said optical guide channel from said input end toward said tip end to impinge on said sidewall of said optical fiber at a predetermined location thereof; and an optical cavity structure formed at said predetermined location at said sidewalls of said optical fiber; wherein optical characteristics of an optical output signal emanating from the input end of said optical fiber correspond to a pressure applied to said optical cavity structure.