ABSTRACT
Light possesses momentum. When treated as a wave, the momentum is often manifested as a radiation pressure; that was first asserted by Maxwell in 1862. In the particle treatment that is introduced by the de Broglie relation, we calculate the momentum of a single photon to be ~k. In this chapter, we will study how light can be used to exert forces on microparticles so as to provide a means of confining and manipulating them. These effects can be analyzed by considering the ray or wave picture of light, and the quantum picture need not be invoked.
