A two bead immunoassay in a micro fluidic device using a flat laser intensity profile for illumination
Abstract
Recently it was demonstrated that a collimated Gaussian beam can be converted to a flattop beam using a Keplerian beam reshaper consisting of two aspheric lenses. Here, using the same optical system, we demonstrate that this flattop profile can be maintained when used in a confocal detection system that focuses the laser beam into a diameter of only 33 µm. The intensity profile of the reshaped beam was determined by imaging the excitation of a constant stream of