Figure 4. Effect of beam parking on reference measurements.

(A) Diffusion times measured as a function of the diagonal distance from the center of the scanning field. An area of 100×100 µm gives a diagonal of approximately 140 µm. (B) Diffusion time map of the 30×30 µm central region. Each color step corresponds to a range of 2.5 µs in diffusion time ι. Both measurements were performed on Alexa 488 10 nM aqueous solution, using a water immersion objective with a NA of 1.2.