TY - JOUR

T1 - High-performance slow light photonic crystal waveguides with topology optimized or circular-hole based material layouts

A1 - Wang,Fengwen

A1 - Jensen,Jakob Søndergaard

A1 - Sigmund,Ole

AU - Wang,Fengwen

AU - Jensen,Jakob Søndergaard

AU - Sigmund,Ole

PB - Elsevier BV

PY - 2012

Y1 - 2012

N2 - Photonic crystal waveguides are optimized for modal confinement and loss related to slow light with high group index. A detailed comparison between optimized circular-hole based waveguides and optimized waveguides with free topology is performed. Design robustness with respect to manufacturing imperfections is enforced by considering different design realizations generated from under-, standard- and over-etching processes in the optimization procedure. A constraint ensures a certain modal confinement, and loss related to slow light with high group index is indirectly treated by penalizing field energy located in air regions. It is demonstrated that slow light with a group index up to ng=278 can be achieved by topology optimized waveguides with promising modal confinement and restricted group-velocity-dispersion. All the topology optimized waveguides achieve a normalized group-index bandwidth of 0.48 or above. The comparisons between circular-hole based designs and topology optimized designs illustrate that the former can be efficient for dispersion engineering but that larger improvements are possible if irregular geometries are allowed.

AB - Photonic crystal waveguides are optimized for modal confinement and loss related to slow light with high group index. A detailed comparison between optimized circular-hole based waveguides and optimized waveguides with free topology is performed. Design robustness with respect to manufacturing imperfections is enforced by considering different design realizations generated from under-, standard- and over-etching processes in the optimization procedure. A constraint ensures a certain modal confinement, and loss related to slow light with high group index is indirectly treated by penalizing field energy located in air regions. It is demonstrated that slow light with a group index up to ng=278 can be achieved by topology optimized waveguides with promising modal confinement and restricted group-velocity-dispersion. All the topology optimized waveguides achieve a normalized group-index bandwidth of 0.48 or above. The comparisons between circular-hole based designs and topology optimized designs illustrate that the former can be efficient for dispersion engineering but that larger improvements are possible if irregular geometries are allowed.

KW - Slow light

KW - Photonic crystal waveguide

KW - Topology optimization

KW - Robust design

U2 - 10.1016/j.photonics.2012.04.004

DO - 10.1016/j.photonics.2012.04.004

JO - Photonics and Nanostructures

JF - Photonics and Nanostructures

SN - 1569-4410

IS - 4

VL - 10

SP - 378

EP - 388

ER -