Two dimensional (2D) nanomaterials like Molybdenum disulfide (MoS2) have been drawing a lot of interest due to their excellent nonlinear optical response. In this research we study thermal lens formation in MoS2 nanoflakes dispersion using mode mismatched pump probe configuration. Observation of the pump and probe beam intensity patterns gave visual insights on time evolution of photothermal lens formation. Effect of MoS2 nanoflakes concentration on thermo-optic properties of dispersions were studied using thermal lens spectroscopy technique. Further, a thermo-optic refraction based technique to measure thermal lens size is proposed. Thermal lens region size increased with increase in pump power. The observed thermal lens modulation is applied to demonstrate ‘normally on’ all optical switch which showed excellent modulation of output beam signal by pump beam.

中文翻译：

---

用于“常开”全光开关的 MoS2 介质中的热光折射

二维 (2D) 纳米材料，如二硫化钼 (MoS2)，由于其出色的非线性光学响应而备受关注。在这项研究中，我们使用模式不匹配的泵浦探针配置研究了 MoS2 纳米薄片分散体中的热透镜形成。泵浦和探测光束强度模式的观察给出了关于光热透镜形成时间演变的视觉洞察。使用热透镜光谱技术研究了二硫化钼纳米薄片浓度对分散体热光性质的影响。此外，提出了一种基于热光折射的技术来测量热透镜尺寸。热透镜区域尺寸随着泵浦功率的增加而增加。