Patent ID: 7020354

Claim:
A fiber optic pressure sensor comprising: a cartridge housing having an end that is exposed to the atmosphere; a thin flexible membrane covering the exposed end of the cartridge housing such that the flexible membrane has an exposed side and a protected side; a fiber bundle disposed within the cartridge housing, the fiber bundle comprising a transmitting fiber having a first and second end, the first end having a polished finish and the second end coupled to a light source, and a multitude of receiving fibers disposed around the transmitting fiber, each receiving fiber having first and second ends, the housing end extending beyond the first end of the transmitting fiber and the first ends of the receiving fibers in a direction along a fiber axis to maintain the membrane at a distance from the fibers, the fiber bundle is disposed within the cartridge housing such that the first end of the transmitting fiber and the first end of each receiving fiber is adjacent to the protected side of the flexible membrane with free space between the first fiber end and the protected side of the flexible membrane; and light sensing means coupled to second end of said receiving fibers, wherein light launched into the transmitting fiber emerges at the polished end, propagates a very short distance in air, and is reflected by the flexible membrane into the receiving fibers, propagates therethrough and is detected by the light sensing means, upon a change in the atmospheric pressure, pressure waves cause the flexible membrane to distort causing the amount of light reflected by the protected side of the flexible membrane and the intensity of the light coupled into the receiving fibers to modulate.