Gaussian beam gradient force traps a dielectric particle. Click to reposition beam focus.
Particle position: (0, 0) nm
Trap depth: 0 kT
Escape events: 0
Physics: A tightly focused Gaussian laser beam creates a gradient force F = (α/2)∇|E|² that pulls a dielectric particle
toward the intensity maximum. The trapping potential U(r) = −(α/2)|E(r)|² forms a harmonic well near the focus.
Brownian motion (kT thermal energy) can cause escape. Higher power deepens the trap; larger beam waist weakens it.
Click anywhere on the canvas to move the beam focus.