Comparison of CW NUV and Pulse NIR Laser Influence on PbSe Films Photosensitivity

Abstract

This paper shows the laser irradiation effect on optical characteristics on PbSe chalcogenide films as a result of irreversible structural modification. The features of film structure and property modification under the action of a continuous wave (CW) laser with a 405 nm wavelength and nanosecond laser pulses with a 1064 nm wavelength are studied. The valence and conduction bands boundaries displacement as a laser radiation result of photothermal action on the film until it darkens and bleaches, is demonstrated. Under CW near ultraviolet (NUV) laser action, the film was modified at a power density of 0.74 to 1.09 kW/cm2. The near-infrared (NIR) laser pulses used ensured the film structure modification at a power density of 1.45 kW/cm2 and a pulse duration of 4 to 20 ns. Scanning with a laser spot in these modes provides the desired change in the film’s optical characteristics, and this becomes a serious alternative to the technology of heat treatment in an oven.

Keywords

• laser modification
• PbSe films
• optical characteristics
• darkening mode
• bleaching mode
• heat treatment