  In this thesis, we report the theoretical and experimental investigations
towards the creation, characterization, and manipulation of quantum
entanglement in a photonic system. We examine two different aspects of quantum
entanglement: In the first part, we discuss the experimental method for the
preparation and characterization of SPDC-based polarization-entangled photon
source. We provide a review study comparing different Entanglement Measures for
non-maximally entangled two-qubit pure states and extend this analysis to
higher-dimensional systems. In the second part, we study the entanglement
dynamics of a two-qubit system in the presence of an Amplitude Damping Channel
and present a scheme based on local unitary operations to protect entanglement
from undergoing Entanglement Sudden Death. We extend the decoherence study to
qubit-qutrit and qutrit-qutrit entangled systems and propose an entanglement
protection scheme for the higher dimensional system.
