Optical analysis of the AMAC IIIS transducer

The AMAC IIIS electrooptical transducer for flow cytometry facilitates simultaneous measurements of electrical impedance and several optical properties of single cells. Ray-trace analysis demonstrates that its spherical exterior permits light rays to emerge effectively undeviated and thus lowers the required numerical aperture of the collecting lens as compared with a flat surfaced transducer. This feature results in an increased light-gathering ability, an increased depth of focus, minimum spherical and chromatic aberrations, and minimizes the optical volume observed.