1 research outputs found
High-performance chiral all-optical logic gate based on topological edge states of valley photonic crystal
For all-optical communication and information processing, it is necessary to
develop all-optical logic gates based on photonic structures that can directly
perform logic operations. All-optical logic gates have been demonstrated based
on conventional waveguides and interferometry, as well as photonic crystal
structures. Nonetheless, any defects in those structures will introduce high
scattering loss, which compromises the fidelity and contrast ratio of the
information process. Based on the spin-valley locking effect that can achieve
defect-immune unidirectional transmission of topological edge states in valley
photonic crystals (VPCs), we propose a high-performance all-optical logic OR
gate based on a VPC structure. By tuning the working bandwidth of the two input
channels, we prevent interference between the two channels to achieve a stable
and high-fidelity output. The transmittance of both channels is higher than
0.8, and a high contrast ratio of 28.8 dB is achieved. Moreover, the chirality
of the logic gate originated from the spin-valley locking effect allows using
different circularly polarized light as inputs, representing "1" or "0", which
is highly desired in quantum computing. The device's footprint is small,
allowing high-density on-chip integration. In addition, this design can be
experimentally fabricated using current nanofabrication techniques and will
have potential applications in optical communication, information processing,
and quantum computing.Comment: 10 pages, 6 figure