Fig. 1. Human red blood cells captured by femtosecond optical tweezers^[27]. (a) Untrapped target cell; (b)--(d) trapped target cells

Fig. 2. Cell fusion process induced by femtosecond optical tweezers and cell state at different time after laser exposure^[39]. (a) 10 s; (b) 1.5 h; (c) 3.0 h; (d) 4.0 h

Fig. 3. Full process of cell transfection with femtosecond optical tweezers^[42]

Fig. 4. Femtosecond optical tweezers system based on metallic nanoantenna arrays^[58]

Fig. 5. Principle and experimental results of femtosecond optical tweezer system based on gold nanocone dimer array^[59]. (a) Schematic principle; (b) reversible trapping and release process of DNA molecules controlled by femtosecond pulses

Fig. 6. Femtosecond optical tweezers system based on metallic bowtie structure and its force analysis^[61].(a) Schematic principle; (b) local electric field distribution; (c) x-component of transverse optical force; (d) y-component of transverse optical force

Fig. 7. Different trapping states of gold nanoparticles under incidence of continuous-wave and femtosecond laser pulses^[65]. (a) Trapping state under incidence of continuous-wave with linear polarization; (b)--(d) trapping states under incidence of femtosecond laser pulses with different polarization directions

Fig. 8. Potential well distribution of particles with different nonlinear refractive index n₂ in different directions^[66]. (a) Horizontal; (b) longitudinal

Fig. 9. Linear and nonlinear trapping of gold nanoparticles under various incident polarization conditions^[67]. (a) Trapping behavior of gold nanoparticles under incidence of femtosecond cylindrical vector beam with polarization order m=2; (b) trapping behavior of gold nanoparticles under incidence of femtosecond cylindrical vector beam with polarization order m=-1; (c)(d) capture effect of rotating direction of incident polarization

Fig. 10. Impact of trapping wavelength on force distribution for Si₃N₄ particles in nonlinear liquid^[68]. (a) Force distribution within wavelength range from 400 nm to 650 nm; (b1)--(b3) longitudinal optical forces exerted on particles under illumination of femtosecond laser pulses at 420, 500, and 600 nm; (c1)--(c3) transverse optical forces exerted on particles under illumination of femtosecond laser pulses at 420, 500, and 600 nm

Fig. 11. Potential well distribution for gold nanoparticle in focused field of femtosecond Gaussian beam with linear polarization^[69]. (a) 3D potential well distribution in focal region; (b) 2D potential well distribution in xoy plane; (c) 2D potential well distribution in xoz plane; (d) 2D potential well distribution in yoz plane