Patent ID: 8449178

Claim:
An optical fiber temperature sensor, comprising: a transmission fiber comprising a first polarization maintaining fiber; a sensing head comprising: a temperature sensing element comprising a second polarization maintaining fiber, wherein one end of said temperature sensing element is connected with said transmission fiber; and a fiber reflector provided at the other end of said temperature sensing element; and an optical transceiver module for transmitting light to said sensing head by said transmission fiber, wherein said first polarization maintaining fiber of said transmission fiber is fusion spliced with said second polarization maintaining fiber of said temperature sensing element, and an angle between a polarization axis of said first polarization maintaining fiber of said transmission fiber and a polarization axis of said second polarization maintaining fiber of said temperature sensing element is 45 degree at a fusion splicing point, wherein said optical transceiver module comprises a light source, an optical circulator, a polarization beam splitter, a first photoelectric detector, and a second photoelectric detector, wherein said optical circulator and said polarization beam splitter are three-port devices, wherein a first port and a second port of said optical circulator are connected with said light source and said first photoelectric detector by a single-mode fiber, respectively, a third port of said optical circulator is connected with a first port of said polarization beam splitter by a single-mode fiber, a second port of said polarization beam splitter is connected with said second photoelectric detector by a single-mode fiber, a third port of said polarization beam splitter is connected with said transmission fiber.