
140
Second Harmonic Generation Imaging
realizable as there will also be at least a small backward component due to the phase mismatch from
dispersion. In the current case, the skin brils are ~
λ
SHG
/5 in diameter (70 and 100 nm for the oim and
WT, respectively) and, based on our phasematching model, are predicted to produce signicant back-
ward SHG (but always smaller than the forward component). To estimate this value, we ran simulations
varying the ratio of the initial emission directionality from 40% to 100% (F
SHG
) at 2.5% increments. We
use these simulations to t to the initial directionality by squaring and summing the residuals between ...