Posted by
Guy Cox-2 on
URL: http://confocal-microscopy-list.275.s1.nabble.com/two-photon-absorption-tp7581862p7581866.html
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I'm sure Colin Sheppard reads this list, and he played with 2P a long time ago, so maybe he will comment. Maybe Warren Zipfel will too. I will just comment that if there is a 'half-way' electronic state available it increases the possibility (cross-section) of two-photon absorption - even though the electron never actually occupies that state! That's quantum mechanics for you!
Guy
Guy Cox, Honorary Associate Professor
School of Medical Sciences
Australian Centre for Microscopy and Microanalysis,
Madsen, F09, University of Sydney, NSW 2006
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From: Confocal Microscopy List [mailto:
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Sent: Monday, 7 April 2014 12:24 PM
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Subject: two-photon absorption
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Dear List--
Is there a physicist out there who can offer an intuitive explanation of how 2-photon absorption occurs? I expect we all know that it isn't that there isn't any half-excited state that allows one photon to boost an electron half-way to the excited state, and the next photon to finish the job. My sense is that it has to do with time-energy uncertainty (a la Heisenberg) but my quantum mechanics is elementary-school level.
Thanks!
Martin Wessendorf
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