Optical Angular Momentum in Classical Electrodynamics

Abstract

Invoking Maxwell's classical equations in conjunction with expressions for the electromagnetic (EM) energy, momentum, force, and torque, we use a few simple examples to demonstrate the nature of the EM angular momentum. The energy and the angular momentum of an EM field will be shown to have an intimate relationship; a source radiating EM angular momentum will, of necessity, pick up an equal but opposite amount of mechanical angular momentum; and the spin and orbital angular momenta of the EM field, when absorbed by a small particle, will be seen to elicit different responses from the particle.

15 pages, 3 figures, 43 equations, 34 references

References in corpus (7)

• Electromagnetic Angular Momentum
• Electromagnetic Force and Momentum
• Angular Momenta and Spin-Orbit Interaction of Nonparaxial Light in Free Space
• Conservation of the spin and orbital angular momenta in electromagnetism
• Spin and Orbital Angular Momenta of Light Reflected from a Cone
• Spin and Orbital Angular Momenta of Electromagnetic Waves in Free Space
• The Charge-Magnet Paradoxes of Classical Electrodynamics