Laguerre–Gaussian induced temperature and refractive index profiles in thermal lens effect

Abstract

In this work, we present a theoretical model that describes induced temperature and refractive index profiles generated by the Laguerre–Gaussian (LG) excitation beam. A comparison between LG and conventional fundamental mode T E M 00 is drawn. It indicates that there is a decrease or increase around the optical axis ( z , r = 0 ) in the refractive index by L G 1 0 and L G 0 5 , thus enabling an enhancement of the refractive index gradient along the radius r . The temperature and refractive index profiles produced by the higher-order LG modes are compared with those of a conventional fundamental T E M 00 Gaussian beam. The results indicate that there is an increase along the radius in the refractive index gradient generated by L G 1 0 and L G 0 5 , which could enhance the sensitivity in photothermal lens detection.