2D Liquid Crystal — Director Field Switching

Nematic director field · Fréedericksz threshold reorientation · crossed-polarizer LCD transmittance

avg tilt θ = 0.0° transmittance T = 0.0% V / V_th = 0.00× state = OFF (bright)

▬ planar (V < V_th) ▬ homeotropic (V > V_th)

Applied voltage V 0.0 V/µm

Threshold voltage V_th 2.0 V/µm

Molecule density 20 × rows

Above V_th, the electric torque overcomes the elastic (Frank) restoring torque and molecules tilt from planar toward homeotropic (field-aligned), reducing the birefringent phase shift and dimming transmitted light between crossed polarizers.