Fig. 4. (Color online) Scattering-intensity map of a single PS bead with a diameter of 565 nm. (a–b) Measurement by balanced detection with lock-in amplifiers (a) and that by the simple difference method (b). The scanning area was 6 × 6 μm with a spatial step of 0.3 μm in the x- and y-directions. The white dashed circles indicate the measured single particle.
© NPSM
