Regenerated Chirped Grating-Michelson Interferometer as a Laser Beam Intensity Profiler for CO2 Laser

摘要

In this paper, we demonstrate the use of regenerated chirped grating (RCG)-Michelson interferometer for the measurement of laser beam intensity profile. When the grating is exposed to CO2 laser irradiation, heat is generated in the fiber due to the absorption of the laser by the glass fiber. The RCG is manufactured from an 18-mm long seed chirped grating through a thermal annealing treatment, to enhance its thermal resistance and durability against the high temperature induced by the CO2 laser irradiation. The intensity profile of the incident laser on the grating can be determined from the phase shift derivative function calculated from the output spectra of the interferometer. By scanning the grating across the laser beam, a 2-D intensity profile of the CO2 laser can be attained.