This project studies an aspect of quantum physics, which is the study of the natural world at its most fundamental level. Experiments with elementary objects such as photons (constituents of light) or electrons (constituents of atoms) has led over the decades to many new technologies, including computers and lasers. The next generation of technology (called quantum technology), might create the means for ensuring perfect security of information on the internet, as well as computers that can solve problems unsolvable using today's hardware. Light, as a carrier of information, plays important roles in such technologies, so the ability to control light more and more finely is crucial for future success. The present study addresses the so-called nonlinear interactions of light that occurs in some substances or materials. For example, when very intense light of a certain color travels through a long solid-glass fiber, new colors can be created by nonlinear interactions. Such color-changing interactions have many uses, both in scientific research and in technological applications. A problem exists though, called "Raman scattering," which leads to the production of many unwanted colors in addition to those desired. In this type of scattering, energy is deposited in the vibrations of molecules making up the medium. These unwanted, randomly produced colors can degrade the purity of the light, so a means to avoid their production is an important goal. The present study is developing such a means by replacing solid-glass fibers with hollow glass fibers filled with xenon gas at extremely high pressure. Because xenon is a "noble gas" it does not form molecules, and so the Raman light scattering mechanism is absent. Optical physics and light-based information science (photonics) offer excellent opportunities to integrate research with science education.
From a more technical perspective, the project addresses the need in quantum optics research for attaining ideal interactions for generating and manipulating quantum-mechanical states of light, including single photons, entangled photons, squeezed states, and entangled states, as well as for performing quantum gate operations and implementing quantum communication methods. Toward these goals, this experimental project studies optical parametric processes using high-density atomic xenon gas confined in hollow-core photonic-crystal fibers (HC-PCF). Such a medium will open up the study of fundamental quantum optical processes without the often-deleterious presence of Raman scattering. Elimination of Raman scattering removes spontaneous photon emission background signals in single-photon sources, and removes Raman-induced frequency shifting in optical soliton propagation, which limits the degree of quantum noise squeezing that can be achieved. It also decreases pump-laser degradation. Such a system could lead to well-controlled nonlinear optical processes for quantum information schemes. Developing the means to manipulate and control the states of quantum systems is of broad interest in science and in quantum information technology, metrology, quantum chemistry, nano-mechanics, etc. The topic brings together quantum opticians with optical device scientists and material scientists.
