Dalian University of Technology successfully developed highly sensitive fiber optic strain sensor

Recently, Huang Hui, a professor from Dalian University of Technology, has developed a high-sensitivity optical fiber strain sensor with adjustable temperature coefficient. Compared with the existing mainstream fiber grating strain sensor, the sensitivity is improved more than 100 times. In particular, it can compensate for the thermal expansion of various measured objects and eliminate the measurement error caused by the change of ambient temperature. The results recently published in the "Scientific Bulletin."

The sensor is considered to be another major industry after the integrated circuit chip. Compared with electrical sensors, fiber optic sensors for flammable and explosive environments such as electromagnetic interference.

Huang Hui team invented the optical fiber strain sensor, the strain film, fiber collimator and transmission rod composition. The transmission rod adopts a knob structure, which is composed of two kinds of nuts and screws with different thermal expansion coefficients. The thermal expansion coefficient of the transmission rod can be accurately adjusted in a wide range to offset the thermal expansion of various measured objects.

In addition, the research greatly improves the detection sensitivity by using a fiber collimator to receive the light beams reflected by the strain film. The developed optical fiber sensor has a detection range of 1.1 × 103με, a detection limit of 5.7 × 10-3με, a maximum operating frequency of 1.18KHz and a temperature coefficient adjustment range of -0.15 ~ + 0.19dB / ° C.