(a) ( Upon examining each image, a few hundred bright spots were identified as dust particles adhered to the surface of the coverslip, with their positions remaining unchanged over time. The focus of these images should be on the dark region in the center and the gray hazed area surrounding it. These scattering images are time-averaged over 35000 frames, meaning that in the dark region, PSNPs have been almost entirely depleted due to thermophoresis. Conversely, in the gray hazed region, the higher the brightness, the higher the probability of the presence of PSNPs on average (i.e., higher concentration). Across all three images, it was confirmed that the diameter of the dark region increases depending on the laser power. This steady-state depletion behavior, which is dependent on laser power, is characteristic of thermophoresis and is worth discussing in comparison with the results of numerical simulations.