Dynamic optical limiting experiments on vanadium dioxide and vanadium pentoxide thin films irradiated by a laser beam

摘要

Vanadium dioxide (VO_(2)) and vanadium pentoxide (V_(2)O_(5)) thin films are irradiated by a near-infrared continuous-wave laser beam and the dynamic optical limiting performance is measured. The temperature varying with time of the films induced by a laser beam is also recorded by an IR thermal sensor. Under the irradiation of a laser beam with an intensity of 255 W/cm~(2) and a spot diameter of 2 mm, the laser beam transmittance of the VO_(2) film decreases from 47percent before phase transition to 28percent after phase transition, and the response time is approx200 ms; the laser beam transmittance of the V_(2)O_(5) film decreases from 51percent before phase transition to 24percent after phase transition, and the response time is approx40 ms. The optical limiting is realized by this laser heating-induced phase transition.