ilent2 / ott

Optical Tweezers Toolbox (Version 1)
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Absorption calculations? #43

Open srtll opened 3 years ago

srtll commented 3 years ago

I think this is a feature request but I may be overlooking a way to do what I want with the existing code so... please bear with me. I am interested in computing not only the scattering of fields from particles but also their absorption. Now, the SMARTIES code base constructs T-matrices using a formulation that looks like: T = -P*inv(Q) but the OTT just calculates T directly without that factorization. This works like: E_incident~(a;b), E_scattered~(p;q), and E_internal~(c;d) where my lowercase letters represent the coefficients of the basis functions, etc. Then (p;q) = T(a;b) tells the scattered from the incident using the T-matrix. But also we can do (p;q) = -P(c;d) and (a;b) = Q(c;d) or (c;d) = inv(Q)(a;b). It is this last bit that I think I need since only if I have the coefficients for the internal field components can I figure out the dissipated power?

As a note, the SMARTIES function that does this is called: "sphCalculatePQ" which says, "Calculates P,Q matrices for a spheroid using the algorithm of [JQSRT 123, 153 (2013)]" [here is the article: https://www.sciencedirect.com/science/article/pii/S0022407313000423 ]