Abstract

Real photonic waveguides are affected by structural imperfections due to fabrication tolerances that cause scattering phenomena when the light propagates through. These effects result in extrinsic propagation losses associated with the excitation of radiation and backscattering modes. In this work, we present a comprehensive review on the extrinsic loss mechanisms occurring in optical waveguides, identifying the main origins of scattering loss and pointing out the relationships between the loss and the geometrical and physical parameters of the waveguides. Theoretical models and experimental results, supported by statistical analysis, are presented for two widespread classes of waveguides: waveguides based on total internal reflection (TIR) affected by surface roughness, and disordered photonic crystal slab waveguides (PhCWs). In both structures extrinsic losses are strongly related to the waveguide group index, but the mode shape and its interaction with waveguide imperfections must also be considered to accurately model the scattering loss process. It is shown that as long as the group index of PhCWs is relatively low ($n_g<30$), many analogies exist in the radiation and backscattering loss mechanisms with TIR waveguides; conversely, in the high $n_g$ regime, multiple scattering and localization effects arise in PhCWs that dramatically modify the waveguide behavior. The presented results enable the development of reliable circuit models of photonic waveguides, which can be used for a realistic performance evaluation of optical circuits.

© 2014 Optical Society of America

Inducing and harnessing stimulated Brillouin scattering in photonic integrated circuits

Benjamin J. Eggleton, Christopher G. Poulton, and Ravi Pant
Adv. Opt. Photon. 5(4) 536-587 (2013)

Loss engineered slow light waveguides

L. O’Faolain, S. A. Schulz, D. M. Beggs, T. P. White, M. Spasenović, L. Kuipers, F. Morichetti, A. Melloni, S. Mazoyer, J. P. Hugonin, P. Lalanne, and T. F. Krauss
Opt. Express 18(26) 27627-27638 (2010)

Recent advances in high-contrast metastructures, metasurfaces, and photonic crystals

Pengfei Qiao, Weijian Yang, and Connie J. Chang-Hasnain
Adv. Opt. Photon. 10(1) 180-245 (2018)

Integrated photonics on thin-film lithium niobate

Di Zhu, Linbo Shao, Mengjie Yu, Rebecca Cheng, Boris Desiatov, C. J. Xin, Yaowen Hu, Jeffrey Holzgrafe, Soumya Ghosh, Amirhassan Shams-Ansari, Eric Puma, Neil Sinclair, Christian Reimer, Mian Zhang, and Marko Lončar
Adv. Opt. Photon. 13(2) 242-352 (2021)

Subwavelength semiconductor lasers for dense chip-scale integration

Qing Gu, Joseph S. T. Smalley, Maziar P. Nezhad, Aleksandar Simic, Jin Hyoung Lee, Michael Katz, Olesya Bondarenko, Boris Slutsky, Amit Mizrahi, Vitaliy Lomakin, and Yeshaiahu Fainman
Adv. Opt. Photon. 6(1) 1-56 (2014)