Second-Harmonic Generation in Optical Fibers and Glass.

摘要

This is the final report for the JSEP fellowship awarded to Vincent G. Dominic. We report on our investigation into the unusual and unexpected effect of second-harmonic generation in optical fibers and optical fiber preforms. We make three important conclusions: Experimental investigations into this effect are simpler and more controllable if carried out in bulk glass samples (optical fiber preforms) rather than in the optical fibers themselves. The induced second-order nonlinearity arises from a DC electric field which is induced inside the glass by light beams containing a fundamental frequency (omega) and its second harmonic (2 omega). The light beams induce the DC electric field through a multiple-photon process. Specifically, we believe that the interference between several multi-photon ionization channels gives rise to anisotropic emission of photoelectrons. The ejected electrons create a photogalvanic current that builds the DC electric field.... Second - harmonic, Generation, Nonlinear optics, Optical fibers.