Thesis (Ph. D.)--University of Rochester. Department of Physics and Astronomy, 2019.
Optical microcavities greatly enhance the strength of light-matter interactions by confining
optical modes to persistently circulate within a small volume of the device material.
The utility of these systems is evidenced by their implementation in a wide variety
of optical applications and fundamental studies. This dissertation focuses on the
development of optical microresonators in the silicon-on-insulator platform for their
application in nonlinear and quantum optics. Single-crystalline silicon microresonators
are particularly well-suited for integrated nonlinear optical applications, due to their
large refractive indices, large Kerr nonlinearities, high quality factor whispering-gallery
modes, and narrowband Raman spectra. Furthermore, nonlinear parametric processes
in silicon can be harnessed to create chip-scale quantum states of light with excellent
characteristics. Moreover, the cavity-enhancement enables the generation of photon
pairs with high purity and narrow spectral linewidth, as well as control over their
spectro-temporal properties. Depending on the application, the photonic quantum states
can be utilized as a source of entanglement or heralded to provide single photons.
We elucidate the multifunctional nature of optical microresonators by investigating
the creation of entangled photon pairs, heralded single photons, and indistinguishable
twin photons within these devices. In each of these domains, the produced photonic
quantum states are characterized and shown to exhibit features that make them best in
class. Additionally, we demonstrate a new technique which can be universally applied
for dispersion compensation in microresonator-based optical parametric processes. By
spatially modulating the microresonator boundary, we show that individual cavity resonances can be targeted and frequency shifted to enable parametric generation. Finally,
we propose and demonstrate a powerful tool for quantum optics, which is based on the
creation and coherent conversion of photonic quantum states between coupled electromagnetic
cavity modes. The modal coupling introduces new creation pathways to a
nonlinear optical process within the device, which then quantum mechanically interfere
to drive the system between states in the time domain. The coherent conversion
entangles the biphotons between propagation pathways, leading to cyclically evolving
path-entanglement and the manifestation of coherent oscillations in second-order temporal
correlations. In turn, by tuning properties of the cavity, we are able to intrinsically
manipulate the generated quantum states and their entanglement properties for the first
time in a photon pair source. It is envisioned that such systems will open a route to
exotic multi-photon states and higher dimensional entanglement.
