Orbital Angular Momentum-Based Optical Fiber Temperature Sensor With Aberration Immunity and Calibration Exemption

Recently appeared OAM-based interferometers have high requirements on the quality of vortex beam and system calibration, otherwise, the rotational symmetry interferogram will be destroyed. A novel OAM-based optical fiber interferometer with Moiré techniques for temperature sensing is proposed. A visualized Moiré probe technique is employed to realize the temperature change indication by rotation calculation. The Moiré probe achieves immunity to vortex wavefront aberrations and precise calibration exemption. The validation experiments were presented with a comparison to existing OAM-based OFIs. The sensing system with a linear temperature measurement sensitivity of about 29 rad/°C with only 0.5 cm PDMS as the sensing part. The temperature measurement resolution is discussed in theory and experiment. The resolution is 7.05*10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−5</sup> °C in theory and 0.003 °C in experiments.