Garrett Hickman

Saturated absorption at nanowatt power levels using metastable xenon in a high-finesse optical cavity

Strong saturated absorption at nanowatt power levels has been demonstrated using metastable xenon in a high finesse optical cavity. The use of metastable xenon allows a high quality factor of Q = 2 × 10(8) to be achieved at relatively high atomic densities without any contamination or damage to the optical surfaces, which is often a problem when using high-density rubidium or other alkali atoms. This technique provides a relatively straightforward way to produce nonlinearities at the single-photon level with possible applications in quantum communications and computing.

Feasibility of single-photon cross-phase modulation using metastable xenon in a high finesse cavity

Abstract Cross-phase modulation at the single-photon level has a wide variety of fundamental applications in quantum optics including the generation of macroscopic entangled states. Here we describe a practical method for producing a weak cross-phase modulation at the single-photon level using metastable xenon in a high finesse cavity. We estimate the achievable phase shift and give a brief update on the experimental progress towards its realization. A single-photon cross-phase modulation of approximately 20 milliradians is predicted by both a straightforward perturbation theory calculation and a numerical matrix diagonalization method.

Nanofiber-segment ring resonator.

We describe a fiber ring resonator comprised of a relatively long loop of standard single-mode fiber with a short nanofiber segment. The evanescent mode of the nanofiber segment allows the cavity-enhanced field to interact with atoms in close proximity to the nanofiber surface. We report on an experiment using a warm atomic vapor and low-finesse cavity, and briefly discuss the potential for reaching the strong coupling regime of cavity QED by using trapped atoms and a high-finesse cavity of this kind.

Low-power cross-phase modulation in a metastable xenon-filled cavity for quantum-information applications

Weak single-photon nonlinearities have many potential applications in quantum computing and quantum information. Here we demonstrate a relatively simple system for producing low-power cross-phase modulation using metastable xenon inside a high finesse cavity. The use of a noble gas such as xenon eliminates the contamination of the high-finesse mirrors that can occur when using alkali metal vapors such as rubidium. Cross-phase shifts of 5 mrad with 4.5 fJ control pulses were demonstrated. Numerical solutions of the master equation are in good agreement with the experimental results, and they predict that cross-phase shifts greater than 1 mrad per control photon should be achievable by reducing the size of the cavity.

Light-Matter Interactions using a Nanofiber-Segment Ring Resonator

We describe experimental work on a nanofiber-based ring resonator that enables strong interactions between the cavity-enhanced field and atoms near the nanofiber surface. This “all fiber” cavity has applications in nonlinear spectroscopy and quantum optics.

Xenon-based nonlinear Fabry-Perot interferometer for quantum information applications

We describe a nonlinear Fabry-Perot interferometer useful for optical quantum information applications. We observe self-phase modulation and other nonlinear effects with ultra-low input powers using metastable xenon in a high-finesse cavity.