Abstract

We report on a method which can be used on more occasions for measuring the laser beam quality M² of light guided by optical fibers based on infrared thermometry. The infrared thermal imager has been used to detect the temperature field of the photothermal sensor which irradiated by fiber laser. Eliminating the error caused by the coefficient of thermal conductivity, by which the temperature field enable us to know the laser beam width in different positions along the direction of laser transmission. With these data, the optical field can be reconstructed. The beam quality M² can be received through curve fitting accurately, which agrees with IOS-standard measurements.

© 2017 Optical Society of America