search

yogevb / a-dda

Automatically exported from code.google.com/p/a-dda
0 stars 0 forks source link

Calculate power of the Gaussian beam #132

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago 
For Gaussian beam ADDA assumes unity amplitude of the electric field in the 
focal point of the beam. However, more readily available quantity in 
experiments is the total beam power. The relation between the two is not always 
trivial. For instance, formulae for approximate descriptions (like barton5) are 
given in the manual (Section 10.4 "Radiation forces"). Formula for the rigorous 
description of a tightly-focussed Gaussian beam is available in e.g. P.C. 
Chaumet, B. Pouligny, R. Dimova, and N. Sojic, “Optical tweezers in 
interaction with an apertureless probe,” J. Appl. Phys. 102, 024915 (2007). 
doi: 10.1063/1.2759892

So the idea is to calculate this power (for unity amplitude of the electric 
field) and write it down to the log file. It will simplify calculation of e.g. 
optical forces for a given beam power. Moreover, conversion between different 
system of units (e.g. CGS and SI) is much simpler for power than for electric 
field amplitude.

Original issue reported on code.google.com by yurkin on 15 Oct 2011 at 9:42