Formation and characterization of an ideal excitation beam geometry in an optofluidic device

An optimal excitation beam shape is necessary to perform reliable flow cytometric analysis but has so far not been implemented in a photonic-microfluidic integrated (i.e. optofluidic) device. We have achieved this feature by integrating a 1D lens system with planar waveguides and microfluidic channel on a substrate using one patterning material via a one-shot process. In this paper, we report the method of design and the performance of specifically formed excitation regions shaped to be ideal for reducing double detections, improving SNR, and for reliable detection in a flow cytometry application. Demonstration of different sizes via changes to lens design shows the ability to control the width of the shaped beam according to a targeted detection.