---
_id: '67134'
abstract:
- lang: eng
  text: <jats:p>Diffractive neural networks (DNNs) are an emerging approach for the
    realization of photonic artificial intelligence, especially due to their suitability
    for machine-vision applications and high-dimensional photonic information processing
    at lower power consumption. However, incorporating optical nonlinear activation
    functions to make DNNs a feasible alternative to their electronic counterpart
    remains a challenge. Here, we investigate the inclusion of second-harmonic generation
    (SHG), as one of the simplest and most efficient types of optical nonlinearities,
    in DNNs. We numerically investigate the impact of SHG on the performance of classification
    tasks in an all-optical nonlinear DNN. Specifically, we investigate and discuss
    the essential requirements for an effective arrangement of a SHG activation in
    single and multilayer DNNs. We find that the performance, in terms of classification
    accuracy and class contrast, is affected strongly by the positioning of the SHG
    activation. Finally, we discuss and outline the constraints for including SHG
    in an experimental realization. Taking these constraints into account, we estimate
    the power-related efficiency of the nonlinear DNN system. Overall, our results
    provide a path towards implementing nonlinear DNNs using the SHG process.</jats:p>
article_number: '35794'
author:
- first_name: M.
  full_name: Braasch, M.
  last_name: Braasch
- first_name: A.
  full_name: Kartashova, A.
  last_name: Kartashova
- first_name: S.
  full_name: Krasikov, S.
  last_name: Krasikov
- first_name: E.
  full_name: Goi, E.
  last_name: Goi
- first_name: T.
  full_name: Pertsch, T.
  last_name: Pertsch
- first_name: S.
  full_name: Saravi, S.
  last_name: Saravi
citation:
  ama: Braasch M, Kartashova A, Krasikov S, Goi E, Pertsch T, Saravi S. Second-harmonic
    generation for enhancing the performance of diffractive neural networks. <i>Optics
    Express</i>. 2026;34(19). doi:<a href="https://doi.org/10.1364/oe.592467">10.1364/oe.592467</a>
  apa: Braasch, M., Kartashova, A., Krasikov, S., Goi, E., Pertsch, T., &#38; Saravi,
    S. (2026). Second-harmonic generation for enhancing the performance of diffractive
    neural networks. <i>Optics Express</i>, <i>34</i>(19), Article 35794. <a href="https://doi.org/10.1364/oe.592467">https://doi.org/10.1364/oe.592467</a>
  bibtex: '@article{Braasch_Kartashova_Krasikov_Goi_Pertsch_Saravi_2026, title={Second-harmonic
    generation for enhancing the performance of diffractive neural networks}, volume={34},
    DOI={<a href="https://doi.org/10.1364/oe.592467">10.1364/oe.592467</a>}, number={1935794},
    journal={Optics Express}, publisher={Optica Publishing Group}, author={Braasch,
    M. and Kartashova, A. and Krasikov, S. and Goi, E. and Pertsch, T. and Saravi,
    S.}, year={2026} }'
  chicago: Braasch, M., A. Kartashova, S. Krasikov, E. Goi, T. Pertsch, and S. Saravi.
    “Second-Harmonic Generation for Enhancing the Performance of Diffractive Neural
    Networks.” <i>Optics Express</i> 34, no. 19 (2026). <a href="https://doi.org/10.1364/oe.592467">https://doi.org/10.1364/oe.592467</a>.
  ieee: 'M. Braasch, A. Kartashova, S. Krasikov, E. Goi, T. Pertsch, and S. Saravi,
    “Second-harmonic generation for enhancing the performance of diffractive neural
    networks,” <i>Optics Express</i>, vol. 34, no. 19, Art. no. 35794, 2026, doi:
    <a href="https://doi.org/10.1364/oe.592467">10.1364/oe.592467</a>.'
  mla: Braasch, M., et al. “Second-Harmonic Generation for Enhancing the Performance
    of Diffractive Neural Networks.” <i>Optics Express</i>, vol. 34, no. 19, 35794,
    Optica Publishing Group, 2026, doi:<a href="https://doi.org/10.1364/oe.592467">10.1364/oe.592467</a>.
  short: M. Braasch, A. Kartashova, S. Krasikov, E. Goi, T. Pertsch, S. Saravi, Optics
    Express 34 (2026).
date_created: 2026-09-12T10:09:12Z
date_updated: 2026-09-12T10:10:04Z
department:
- _id: '975'
doi: 10.1364/oe.592467
intvolume: '        34'
issue: '19'
language:
- iso: eng
publication: Optics Express
publication_identifier:
  issn:
  - 1094-4087
publication_status: published
publisher: Optica Publishing Group
status: public
title: Second-harmonic generation for enhancing the performance of diffractive neural
  networks
type: journal_article
user_id: '115260'
volume: 34
year: '2026'
...