Patent ID: 7196318

Claim:
A fiber-optic sensing system for measuring a first physical parameter, comprising: a sheath having a sealed tip, a main body and a formed-through opening formed on the main body and sealed with a flexible diaphragm; an optical fiber thereon comprising a first fiber-grating-based sensor, the optical fiber with the first fiber-grating-based sensor being inserted into an interior of the sheath and only one side of the optical fiber being fixed onto the main body, a segment of the optical fiber encompassing the first fiber-grating-based sensor being underneath the diaphragm; an optical device for emitting a sensing light signal into a head end of the optical fiber and receiving a first reflected light signal resulting from the sensing light signal reflected by the first fiber-grating-based sensor, and wherein when the sheath is inserted into a region where the first physical parameter needs to be measured, the region bring, through the diaphragm, a bending strain to the first fiber-grating sensor to induce a variation on the first reflected light signal; and a signal processing device, coupled to the optical device, for interpreting the variation on the first reflected light signal into the first physical parameter.