Improved broadband performance of an adjoint shape optimized waveguide crossing using a Levenberg-Marquardt update

We derive an adjoint shape optimization algorithm with a compound figure of merit and demonstrate its use with both gradient descent and Levenberg-Marquart updates for the case of SiO -buried SOI coplanar waveguide crossings. We show that a smoothing parameter, basis function width, can be used to e...

Full description

Saved in:
Bibliographic Details
Published in:Optics express 2019-08, Vol.27 (17), p.24765-24780
Main Authors: Hoffman, Galen B, Dallo, Christina, Starbuck, Andrew, Hood, Dana, Pomerene, Andrew, Trotter, Douglas, DeRose, Christopher T
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We derive an adjoint shape optimization algorithm with a compound figure of merit and demonstrate its use with both gradient descent and Levenberg-Marquart updates for the case of SiO -buried SOI coplanar waveguide crossings. We show that a smoothing parameter, basis function width, can be used to eliminate small feature sizes with a small cost to device performance. The Levenberg-Marquardt update produces devices with larger bandwidth. A waveguide crossing with simulated performance values of > 60 dB cross power extinction ratio and > -0.08 dB through power over the 1500-1600 nm band is presented. A fabricated device is measured to have a maximum of -0.06 dB through power and a 50 dB cross power extinction ratio.
ISSN:1094-4087
1094-4087
DOI:10.1364/OE.27.024765