Figure 4. Particle scanning and position estimation.

(a) Scanning image of 190 nm fluorescent beads with 2D-EOD driving the laser in a 1 × 1 µm square knight’s tour pattern. Fluorescence intensity is denoted by color. Unit: kHz. (b) Estimation of x_k, the particle’s position relative to the center of the 2D-EOD scan in micrometers. The color in b, c, and d denotes the estimated position. Unit: µm. (c) Estimation of y_k in micrometers. (d) Estimation of z_k, the particle’s position relative to the axial center of the TAG lens scan in micrometers. (e) Estimated particle position y_k as a function of the stage position averaged over the entire grid from (c). Note that the estimated particle position acquired from the position estimation algorithm (y_k) agrees with the real position. (f) Estimated particle position z_k as a function of the stage position averaged over the entire grid from (d). The estimated position shows a linear relationship with particle’s real position over 1 × 1 × 2 µm range in X, Y, and Z direction. Note that the estimated particle position acquired from the position estimation algorithm (z_k) agrees with the real position. The estimated position shows a linear relationship with particle’s real position over a 1 × 1 × 2 µm range in X, Y, and Z direction. The white scale bars in (a–c) represent 500 nm and the black scale bar in (d) represents 2 µm.