Optical Tweezers Trap

A focused laser beam creates a gradient force that traps microscopic particles. Brownian motion causes jitter, but the restoring force κ·x keeps the bead confined. Click to reposition the trap.

Trap stiffness κ: — pN/μm
Displacement: — nm
Gradient force: — pN
Brownian rms: — nm
Escape events: 0

Laser Power (mW): 10

Beam Waist w₀ (nm): 500

Particle Radius (nm): 250

Temperature (K): 300

Gradient force: F = −κx, where κ ∝ P/w₀². Equipartition: ½κ⟨x²⟩ = ½k_BT → ⟨x²⟩ = k_BT/κ