Nonlinear optical response of molybdenum disulfide film and its application for Yb: YAG solid laser

Abstract

Molybdenum disulfide (MoS₂) film has been recognized as a promising optical modulator for pulsed laser due to its excellent optical nonlinear characteristic. In this article, continuous and large-area MoS₂ film growth on quartz substrate by radio frequency (RF) magnetron sputtering was researched. The Raman spectroscopy and X-ray diffractometer (XRD) were implemented to demonstrate the excellent crystalline quality of the MoS₂ thin film. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were utilized to assess the thickness and morphology of the created MoS₂ thin film, indicating that the MoS₂ film exhibits surface uniformity and comprises only a few layers. Z-scan technology and balanced synchronous twin-detector technique were applied to reveal the nonlinear optical characteristics of MoS₂ film growth on quartz substrate, and a large third order nonlinear absorption coefficient of -3.94×10⁴ cm/GW and modulation depth of 21.8% was obtained, respectively. Furthermore, we experimentally demonstrated a bulk Yb: YAG crystal solid Q-switched laser based on MoS₂ film as saturable absorber (SA). Nanosecond laser pulse trains and the pulse duration of 703 ns were obtained, that is the narrowest pulse duration for the Yb: YAG solid Q-switched laser based on MoS₂ film for our knowledge. The findings provide a pathway for the employment of the MoS₂ growth on quartz substrate by RF magnetron sputtering in near-infrared pulsed laser applications.