Reflection and transmission of light through transparent materials at high power densities

A model is proposed to explain the reflection and transmission of laser light through transparent materials. This model is valied for laser intensities less than threshold power for diffuse scattering. Our model takes into account multiphoton absorption or cascade effects causing the electrons to jump from the valence band to the conduction band. The problem is solved analytically using Maxwell's equations with a time-dependent electric conductivity and Newton's law for the mobile electrons. Our results are compared with experiments in the intensity range from ${10}^{11}$ to ${10}^{13}$ W/${\mathrm{cm}}^2$. Excellent agreement between the present calculations and the experiment is obtained. We predict that the reflection and transmission coefficients for transparent dielectrics are not very sensitive to the irradiating-laser-light frequency.