There are two different proposals for the momentum of light in a transparent dielectric of refractive index n: Minkowski's version nE=c and Abraham's version E=

We show in this paper that the quantized energies of light in vacuum can be derived directly from the classical electromagnetic theory through the consideration of statistics based on classical physics, which are just a series of expectation values corresponding to relatively stable statistic distributions of electromagnetic harmonic oscillators. Therefore, the quantization of energy is an intrinsic property of light as a classical electromagnetic wave and has no need of being related to particles. The theory developed in this paper is also used to derive the energy equipartition theorem and the discrete levels of hydrogen atom from classical mechanics.

A new wave coupling theory of linear electrooptic effect has been developed starting from Maxwell's equations and considering the second-order nonlinearity. We give a general solution for the resultant equations. The solution is useful in describing linear electrooptic effect for a light wave propagating along an arbitrary direction with an external dc electric field along any direction in any crystal. Applications to the design of some electrooptic devices are de-scribed.

We have created a one-(rather than two-) dimensional quasi-steady-state photorefractive spatial soliton induced by a laser beam instead of an applied electric field. The formation of this type of spatial soliton depends on the intensity of the self-trapped beam, which is different from quasi-steady-state spatial solitons reported in the literature. The optically induced spatial soliton can be exploited in all optical switching applications.

We have observed two-dimensional bright photovoltaic photorefractive spatial soliton for the first time in a Cu:KNSBN K0.25Na0.75Sr1.5Ba0.5Nb5O15 crystal. Characteristics of the observed spatial soliton are explained by an equivalent electric field induced by the background irradiance.