Handbook of Biomedical Optics

Fluorescence Microscopy with Structured Excitation Illumination 553

B 26.2 I  F

S  O T F

T

he process of image formation can be described in

Fourier space. us, the Fourier-transformed uo-

rescence molecule distribution is multiplied by the

Fourier-transformed PSF, which is denoted as optical trans-

fer function (OTF). Applying a Fourier back-transformation

leads to the resulting image in real space.

In Fourier transformation theory, it can be shown that

any periodic function f(x) = f(x + L) (L is the period length)

is decomposable of sine and cosine functions (the so-called

Fourier series