Phrase guide

Fresnel number

noun · 1 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.

No pronunciation record was provided for this word.

1

noun

Meaning 1

A dimensionless quantity (denoted F), such that for an electromagnetic wave passing through an aperture and hitting a screen, F=(a2)/(Lλ) where a is the characteristic size (e.g. radius) of the aperture, L is the distance of the screen from the aperture, and λ is the incident wavelength.

Definition source: English Wiktionary via Wiktextract

Topics: engineering, natural-sciences, optics, physical-sciences, physics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

History

Etymology

Named after the physicist Augustin-Jean Fresnel.