The optical system used in the experiments is illustrated in Supporting Information Figure . An inverted optical microscope (IX-73, Olympus) was used for sample observation and laser irradiation. The PSNPs were observed using a dark-field condenser (U-DCD, Olympus) to capture the scattering images. A monochrome CMOS camera (CS235CU, Thorlabs) was used. For observation and laser irradiation, an objective lens with NA = 0.65 designed for near-infrared wavelengths was used (LCPLN50XIR, Olympus). A CW fiber-output laser with a wavelength of 1560 nm (PUMP-1560, NPI Lasers) served as the laser source. The linearly polarized laser beam was collimated with a plano-convex lens and focused to the diffraction limit by the objective lens before being irradiated onto the sample. The light intensity profile in the x-y plane at the sample position was measured using a near-infrared camera (Cat# 56-567, 1460-1600 nm Near-Infrared Camera, Edmund Optics), and the beam's full width at half maximum was found to be 2.1 µm (See Supporting Information Figure ).