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I've a question about super-resolution microscopy: what is the standard way
of estimating how much power reaches the sample in PALM/STORM experiments?

Let's say I've measured my laser power at the tip of the coupling optical
fiber (entering the microscope stand) to be 100 mW. How do I estimate the
power on the sample (in kW/cm^2) if I use a 100X objective? Using the TIRF
arm field number (16 mm) and objective magnification (100X) I get an
illuminated area of 20,000 µm^2, so even with 100% efficiency (which is
unlikely given the objective non-perfect transmission), that only
translates into 2 kW/cm^2 on the sample, which is quite low.

Given than a lot of STORM papers report powers in the 5-50 kW/cm^2 range, I
wonder if something is wrong in my calculation? I don't want a precise
measurement (which would necessitate measuring the actual output downstream
of the objective), but more a reliable way to get an estimate.

Thanks for your help,

--
Christophe Leterrier
Chercheur
Equipe Architecture des Domaines Axonaux
CRN2M CNRS UMR 7286 - Aix Marseille Université