🌐EnglishEnglishEspañol中文日本語EntityQ649739· pop 7· linked from 7 articlesSmith–Purcell effectthe precursor of the free-electron laserAvailable in 6 languagesEspañol日本語HebrewHungarianUkrainianvia Wikidata sitelinks · CC0ConnectionslightEntityelectronEntityCategoriesQuantum optics