Simple fiber-optic low-temperature sensor that uses microbending loss.

A simple fiber-optic temperature sensor is constructed that uses the temperature dependence of microbending loss. The sensor is tested and shows high sensitivity and a strict linear scale over a wide range from 20 to 180 K. It is shown that a proper choice of signal wavelength can be used either to make the sensor more sensitive or to make it independent of changes in laser wavelength.