Fig. 1. Schematic design of an optical tweezers capture system in the deep sea

Fig. 2. Schematic diagram of the optical path of the optical tweezers system

Fig. 3. Dispersion curves of seawater at 1.5 km and pure water

Fig. 4. Absorption spectra of pure seawater，colored dissolved organic matter and impurities，and scattering spectra of pure seawater^［29-30］

Fig. 5. Axial capturing force（F_z）curves of optical tweezers on microspheres with different radii in seawater and pure water

Fig. 6. Lateral capturing force（F_x）curves of optical tweezers on microspheres with different radii in seawater and pure water

Fig. 7. Point-line plots of maximum axial capture force and maximum lateral capture force for optical tweezers at 1.5 km depth and in pure water