Talk:Purcell effect

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the citation Phys. Rev. 69, 681 (1946) is incorrect: no such article exists. does anyone have a correct citation ?

Number density of particles? If so, why is λ_c/n a wavelength? 89.217.11.36 (talk) 09:09, 22 February 2015 (UTC)Reply

n is the refractive index. --88.217.170.249 (talk) 16:23, 9 February 2017 (UTC)Reply

Reference 1 leads to another site than indicated. — Preceding unsigned comment added by 2001:660:4701:1002:34E3:76EB:DDF4:F8B2 (talk) 08:31, 11 December 2018 (UTC)Reply

The correct reference is "E.M. Purcell, Spontaneous emission probabilities at radio frequencies, Phys. Rev. 69, 681 (1946).". However, it is hard to find in the APS system, since this is a short note inside the article "Proceedings of the American Physical Society, MINUTEs oF THE SPRING MEETING AT CAMBRIDGE, APRIL 25— 27, 1946". This article can be obtained through "https://doi.org/10.1103/PhysRev.69.674.2." or "https://journals.aps.org/pr/pdf/10.1103/PhysRev.69.674.2". Also, as far as I can see, the current references [1] and [2] are (in principle) identical, so one of them should be omitted and the other changed. Disu56 (talk) 08:23, 15 July 2026 (UTC)Reply

It's frequency (${\displaystyle \nu }$, not ${\displaystyle \upsilon }$). Evgeny (talk) 16:03, 14 September 2022 (UTC)Reply

The Purcell factor described here only applies in the weak light-matter coupling regime where the cavity loss rate is much larger than the (collective) light-matter coupling strength. In the strong coupling regime, the spontaneous emission rate is essentially just the cavity loss rate, which is inversely proportional to Q.

This is because spontaneous emission from a molecule inside a cavity can be thought of as a two-step process: the molecule excitation transfers to the cavity mode through light-matter coupling, then the cavity excitation transfers to external (far-field) photon modes through cavity loss. For weak coupling, the rate-limiting step is the first step, while for strong coupling, it is the second step. ~2026-15880-61 (talk) 03:40, 13 March 2026 (UTC)Reply