QUANTUM KRISPY KREME SEMINAR AND PHD DEFENSE

FREE COFFEE AND DONUTS PROVIDED!

WHAT: QUANTUM NONLINEAR OPTICS:
APPLICATIONS TO QUANTUM METROLOGY, IMAGING, AND INFORMATION

WHO: RYAN GLASSER (LSU)

WHEN: 3:40PM FRI 27 MAR 09

WHERE: NICHOLSON 435

ABSTRACT:

The fields of quantum and nonlinear optics have given rise to a variety of non-classical states
of light that have been proven to surpass certain limitations set by classical physics. Namely,
certain squeezed and entangled states have been shown to beat the shot-noise limit when
making precision phase measurements in interferometry, as well as write lithographic patterns
that are smaller than classically allowed by the Rayleigh diffraction limit. Additionally, single-
photon sources and entangled photon pairs have given rise to provably secure quantum key
distribution for cryptography.

Producing these quantum states of light has proven a difficult task. Nonlinear crystals,
when pumped by a laser, produce pairs of single photons via the process of spontaneous
parametric down conversion (SPDC). This process is mediated by the second order nonlinear
susceptibility of the material. When pumped in a high gain regime, these crystals give rise
to optical parametric amplification, which is a viable source of squeezed light. The vast
majority of research in this area has focused on crystals that are seeded by vacuum in their
two modes.

This dissertation concerns the field of quantum nonlinear optics. It is an investigation
into the processes that occur when nonlinear materials interact with the electromagnetic
field on the single photon level. I have focused on seeding nonlinear crystals with quantum
states of light, including single photons and entangled states. This process results in various
states directly applicable to interferometry, imaging, and cryptography. Another application
investigated is an absolute radiance measurement via stimulated parametric down conversion
resulting from non-vacuum seeding of a nonlinear crystal.

Additionally, other nonlinear processes, including four-wave mixing, nonlinear magneto-
optical effects and coherent population trapping in warm atomic vapor involving quantum
states of light are investigated. The process of seeding third-order nonlinear interactions, such as in atomic vapors, gives rise to a variety of interesting, non-classical phenomena such
as entangled image transfer and nonlocal imaging. Strong analogies between SPDC and four-
wave mixing are drawn. I also experimentally show an all optical pi-only phase shift of one
light beam via another in warm Cesium vapor.