Fig. 9.6 — Transverse forward scattering and transverse position detection

Transverse forward scattering and transverse position detection. (a) Images of the field at the back focal plane of the condenser for various particle radii a and particle transverse displacement C = [C_x , 0, 0]. The circles delimit the areas of the field that is captured by the condenser lens with NA_o = 0.20, 0.65 and 1.20 (solid line) from the centre outwards. Signal from a (b) QPD and (c) PSD as a function of C_x for the case of a = 400 nm (dotted line), a = 600 nm (dashed line) and a = 1000 nm (solid line) for an incident beam with power 1 mW and detection NA_c = 1.20.