Currently, we are pursuing research in the following areas, along with several collaborators.

Field-Intensity Correlation Functions - A new type of correlation function, first investigated by Dr. Howard Carmichael's group is a field-intensity correlation function. Experimentally, one gets a trigger signal from a photodetector (probability proportional to the intensity of the field) and then performs a balanced homodyne measurement of the field conditioned on the first photodetection. Measurements have been made at Dr. Luis Orozco's group at SUNY Stony Brook for N atoms in a driven damped optical cavity, making electric field measurements at the sub-photon level. We have participated in doing calculations outside the weak field limit. We have also done calculations where the transmitted/fluorescent field is measured based on photodetection in the fluorescent/transmitted mode's. We have also done calculations for a two-level atom inside an optical parametric oscillator in all 4 cases (T/T, T/F, F/T, F/F). Also for a cavity QED system with 1-d quantized center of mass motion

Cavity QED with Quantized Center of Mass motion - We have considered the photon statistics and wave-particle correlations for a cavity QED system, with one atom, and an optical lattice along the cavity axis. We find that in many cases, it is not neccesarily advantageous to use a localized atom as opposed to an atomic beam. The nonclassical behavior in the wave-particle correlations are more robust than those in the photon-photon (intensity) correlations.

Quantum Information and Computation - We are interested in the use of cold atoms, optical lattices, and cavity QED systems as elements of a quantum computation/communication system. We are looking at ways in which disspipative processes can create entanglement in a variety of cavity QED systems. The cavity QED system with quantized center of mass motion gives us extra degrees of freedom to create quantum logic gates and network elements.

Numerical Simulations of Nano-Probes and Nano-Structures - We are using Finite Difference Time Domain methods to study various nanoscale metallic particles. We look for solutions of Maxwell's equations for such structures, to calculate the electric field as a function of position on and around the nanoparticles.  In addition, the plasmon resonances are identified as a function of particle size, geometry, and type of metal.  These results provide information on what might be seen by a near-field probe when light of a particular polarization illuminates the metallic particles brought in close proximity to systems under investigation. We consider various nonlinear interactions in systems which have applications in optical communications, electronics, and bio-sensing. This is being done in collaboration with Dr. Yarrison-Rice's group and others at the M. U. Institute for Nanotechnology.

Quantum Interference Effects in Cavity QED Systems- Quantum interference between two "paths" can enhance or suppress the probability of transitions. Recently there has been much interest in Electromagnetically Induced Transparency (EIT) and Lasing Without Inversion (LWI). These phenomena deal with interference between indistinguishable "paths" for a photon to take in a 3-level system. We have mainly concentrated on a single-two level atom inside a resonant cavity, with weak excitation, in the strong coupling regime. This system is a 3-level system with coupling of the upper levels due to atom-cavity coupling. We have identified quantum interference effects in spectra as well as in the photon statistics of this system. Recent experimental results on the photon statistics by researchers at S. U. N. Y. Stony Brook go outside the weak-field limit, and we are modeling those systems. Another system of interest is a two-level atom inside an Optical Parametric Oscillator, a source of squeezed light. Here we see new interference phenomena in the spectra, perhaps due to the indistinguisability of the source pair of photons. We have been collaborating with researchers at the University of Dayton and the University of Arkansas.

Photon Statistics and Dynamics of Trapped Atoms - We are working on the photon statistics of optically dense atom clouds in MOT's, in support of the experiment's in Dr. Bali's lab. We are also working on the dynamics of atomic motion in optical lattices, and possible signatures in photon-correlation experiments.

Measurement of Squeezing - We are working on a better understanding of the typical squeezing measurements, for short lived atoms and weaker driving fields off resonance, and the experiments of Thomas, Bali and *, using a stochastic Schroedinger equation approach.

Microcavity Lasers - Recent advances in Cavity Quantum Electrodynamics have enabled researchers to control the emission properties of atoms. This may lead to more efficient lasers, particularly small semiconductor lasers for use in optical processing, communication, and displays. Systems include bulk and quantum well media inside microdisk lasers, and localized excitons in thin quantum wells with Bragg reflectors as in a VCSEL. We are working with colleagues at the University of Dayton, University of Oregon, and Lucent Technologies Bell Laboratories to understand the properties of the light emitted by such lasers.

Interaction of Squeezed Light with Optical Systems- Squeezed light is light that is in some sense "quieter" than no light at all. Since the seminal work of Crispin Gardiner, the interaction of squeezed light with optical systems has been of much interest. We have investigated a single two-level atom inside a resonant cavity as well as Scully-Lamb type lasers. Here we have worked with researchers at the Unversity of Dayton and the University of Arkansas.

Photonic Band Gap Materials and Applications to Quantum Optics - We are doing some preliminary band-gap and mode calculations in support of experiments underway  in Dr. Yarrison-Rice's group. The idea is to investigate these novel materials and their application to waveguides and fundamental cavity QED experiments.

 Photorefraction- Pedagogical treatment of the photorefractive effect, in collaboration with Dr. Yarrison-Rice’s group.

 Modern Optics Labs for Upper Level Undergraduates- NSF funded senior level sequence. Laser Physics in the fall, and Spectroscopy in the spring. Drs. Marcum and Yarrison-Rice are the Co-PI’s. Lab work is emphasized, including lasers, fiber optics, second-harmonic generation, signal processing using phase conjugation, optical tweezers, saturation spectroscopy, and a magneto-optical trap.

 Current Group Members - Those that do most of the work.

Alumni- Where are they now?

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