Abstract

Non-reciprocal optical components such as isolators and circulators are crucial for preventing catastrophic backreflection and controlling optical cross talk in photonic systems. While non-reciprocal devices based on Brillouin intermodal transitions have been experimentally demonstrated in chip-scale platforms, harnessing such interactions has required a suspended waveguide structure, which is challenging to fabricate and is potentially less robust than a non-suspended structure, thereby limiting the design flexibility. In this paper, we numerically investigate the performance of a Brillouin-based isolation scheme in which a dual-pump-driven optoacoustic interaction is used to excite confined acoustic waves in a traditional ridge waveguide. We find that acoustic confinement, and therefore the amount of Brillouin-driven mode conversion, can be enhanced by selecting an appropriate optical mode pair and waveguide geometry of two arsenic-based chalcogenide platforms. Further, we optimize the isolator design in its entirety, including the input couplers, mode filters, the Brillouin-active waveguide as well as the device fabrication tolerances. We predict such a device can achieve 30 dB isolation over a 38 nm bandwidth when 500 mW pump power is used; in the presence of a ${\pm}10\,\,\rm nm$ fabrication-induced width error, such isolation can be maintained over a 5–10 nm bandwidth.

© 2023 Optica Publishing Group

Design for broadband on-chip isolator using stimulated Brillouin scattering in dispersion-engineered chalcogenide waveguides

Christopher G. Poulton, Ravi Pant, Adam Byrnes, Shanhui Fan, M. J. Steel, and Benjamin J. Eggleton
Opt. Express 20(19) 21235-21246 (2012)

Stimulated Brillouin scattering by surface acoustic waves in lithium niobate waveguides

Caique C. Rodrigues, Roberto O. Zurita, Thiago P. M. Alegre, and Gustavo S. Wiederhecker
J. Opt. Soc. Am. B 40(5) D56-D63 (2023)

On-chip stimulated Brillouin scattering

Ravi Pant, Christopher G. Poulton, Duk-Yong Choi, Hannah Mcfarlane, Samuel Hile, Enbang Li, Luc Thevenaz, Barry Luther-Davies, Stephen J. Madden, and Benjamin J. Eggleton
Opt. Express 19(9) 8285-8290 (2011)

Suspended mid-infrared waveguides for Stimulated Brillouin Scattering

M. K. Schmidt, C. G. Poulton, G. Z. Mashanovich, G. T. Reed, B. J. Eggleton, and M. J. Steel
Opt. Express 27(4) 4976-4989 (2019)

Stimulated Brillouin scattering in metamaterials

M. J. A. Smith, C. Wolff, C. Martijn de Sterke, M. Lapine, B. T. Kuhlmey, and C. G. Poulton
J. Opt. Soc. Am. B 33(10) 2162-2171 (2016)