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Data transmission at high rates, reaching tens of Gb\/s, and over distances that can reach hundreds of kilometers, still faces barriers to improvement, such as distortions in the transmitted signals. Such distortions include chromatic dispersion, which causes a broadening of the transmitted pulse. Therefore, the development of solutions for the adequate recovery of such signals distorted by the complex dynamics of the transmission channel currently constitutes an open problem since, despite the existence of well-known and efficient equalization techniques, these have limitations in terms of processing time, hardware complexity, and especially energy consumption. In this scenario, this paper discusses the emergence of photonic neural networks as a promising alternative for equalizing optical communication signals. Thus, this review focuses on the applications, challenges, and opportunities of implementing integrated photonic neural networks for the scenario of optical signal equalization. The main work carried out, ongoing investigations, and possibilities for new research directions are also addressed. From this review, it can be concluded that perceptron photonic neural networks perform slightly better in equalizing signals transmitted over greater distances than reservoir computing photonic neural networks, but with signals at lower data rates. It is important to emphasize that photonics research has been growing exponentially in recent years, so it is beyond the scope of this review to address all existing applications of integrated photonic neural networks.<\/jats:p>","DOI":"10.3390\/photonics12010039","type":"journal-article","created":{"date-parts":[[2025,1,6]],"date-time":"2025-01-06T08:08:52Z","timestamp":1736150932000},"page":"39","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Integrated Photonic Neural Networks for Equalizing Optical Communication Signals: A Review"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5259-9380","authenticated-orcid":false,"given":"Lu\u00eds C. B.","family":"Silva","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering, Federal University of Esp\u00edrito Santo, Fernando Ferrari Avenue, Vit\u00f3ria 29075-910, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8333-8012","authenticated-orcid":false,"given":"Pablo R. N.","family":"Marciano","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Federal University of Esp\u00edrito Santo, Fernando Ferrari Avenue, Vit\u00f3ria 29075-910, Brazil"}]},{"given":"Maria J.","family":"Pontes","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Federal University of Esp\u00edrito Santo, Fernando Ferrari Avenue, Vit\u00f3ria 29075-910, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0972-098X","authenticated-orcid":false,"given":"Maxwell E.","family":"Monteiro","sequence":"additional","affiliation":[{"name":"Federal Institute of Esp\u00edrito Santo (IFES), Serra 29166-630, Brazil"}]},{"given":"Paulo S. B.","family":"Andr\u00e9","sequence":"additional","affiliation":[{"name":"Department of Electrical and Computer Engineering, Instituto de Telecomunica\u00e7\u00f5es, Instituto Superior T\u00e9cnico, University of Lisbon, 1049-001 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4083-992X","authenticated-orcid":false,"given":"Marcelo E. V.","family":"Segatto","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Federal University of Esp\u00edrito Santo, Fernando Ferrari Avenue, Vit\u00f3ria 29075-910, Brazil"}]}],"member":"1968","published-online":{"date-parts":[[2025,1,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1201","DOI":"10.1007\/s00508-021-01930-y","article-title":"Role of new digital technologies and telemedicine in pulmonary rehabilitation: Smart devices in the treatment of chronic respiratory diseases","volume":"133","author":"Fekete","year":"2021","journal-title":"Wien. Klin. 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