Abstract:
Active control and manipulation of electromagnetic waves are highly desirable
for advanced photonic device technology, such as optical cloaking, active
camouflage and information processing. Designing optical resonators with high
ease-of-control and reconfigurability remains a open challenge thus far. Here
we propose a novel mechanism to continuously reconfigure an optical resonator
between one-port and two-port configurations via \emph{phase-change material}
for efficient optical modulation. By incorporating a phase-change material
VO$_2$ substrate into a photonic crystal optical resonator, we computationally
show that the system behaves as a one-port device with near-perfect absorption
and two-port device with high transmission up to 92% when VO$_2$ is in the
metallic rutile phase and insulating monoclinic phase, respectively. The
optical response can be continuously and reversibly modulated between various
intermediate states. More importantly, the proposed device is compatible with
wide-angle operation and is robust against structural distortion. Our findings
reveal a novel device architecture of \emph{port reconfigurable} optical
resonator uniquely enabled by switchable optical properties of phase change
material.