Nonlinear Optical Interactions in Rb-Filled Photonic Band-Gap Fibers

Cornell University, Ithaca NY

Investigators

Abstract

Photonic band-gap fibers (PBGF) are able to guide light via diffraction rather than by total internal reflection. Such fibers allow for simultaneous high confinement of light and a gas in a hollow-core region. As a result, PBGF's offer a unique advantage over free-space, focused geometries for interactions of light with gases due to their unmatched ratio of interaction length to cross-sectional core area. The proposed effort involving PBGF's will entail studies in two main areas: 1) ultralow power light-matter interactions with Rb atoms, and 2) the propagation of intense ultrashort laser pulses and high harmonic generation. For the work with Rb atoms, high density vapors will be produced by the process of light-induced atomic desorption which will allow for exploration of one- and two-photon nonlinear interactions at extremely low light levels. The effort on high-harmonic generation will explore the possibility of generating light in the deep ultraviolet using femtosecond laser pulses at modest pulse energies by confining both the fundamental and harmonic fields within the core and through use of quasiphasematching techniques. Such a system would have immediate applications in the creation of compact fiber-based ultraviolet and extreme ultraviolet sources, which cannot be realized using conventional silica glass fiber. The graduate students supported by this funding will develop a foundation for understanding a wide range of interactions of light with matter and will acquire the experimental skills necessary for characterizing such interactions. In addition, one or two undergraduates per year will work in the PI's laboratory on projects related to this research effort and gain their first experience of performing research in optical physics. The PI and the PhD students will participate extensively in outreach activities at Cornell via the NSF-funded Center for Nanoscale Systems Institute for Physics Teachers (CIPT) and the Cornell Center for Materials Research. In addition, the PI will continue to deliver optics-related seminars to high-school teachers and students.