OPTICAL FIBER PRESSURE SENSOR WITH UNIFORM DIAPHRAGM AND METHOD OF FABRICATING SAME

摘要

An optical fiber sensor (100) can be used to measure pressure with high sensitivity and fine resolution. As a cavity (108) at the end of the sensor expands or contracts, the spectrum of a beam reflected from the end of fiber shifts, producing a change linked to pressure exerted on the sensor. Novel aspects of the present inventive sensor include the direct bonding of a silica thin film diaphragm (110) to the optical fiber with localized or confined heating and a uniform thickness of the diaphragm. The resulting sensor has a diameter that matches the diameter of the optical fiber. Because the sensor is all silica, it does not suffer from temperature- induced error. In addition, the sensor can be very sensitive because the diaphragm can be very thin; it can also make highly repeatable measurements due to its very uniform thickness.