FIGURE 1.

Data generated by two-dimensional simulation. The plot shows a trajectory of a molecule with D_j = 0.25 μm²/ms and m_j = 1 through the circular region centered at the laser focus with radius R_max = 2 μm. The inner, dashed circle represents the laser beam waist. Entry and exit points are indicated. Displayed molecule positions are updated in 0.5-μs increments. Circles indicate the molecule's position at each photon arrival time. Labeled points correspond to the times at which the distributions in Fig. 3 are shown.