Laser-induced fluorescence (LIF) is widely used in biological detection system in characteristic of high sensitivity and selectivity, especially for microarray biochip readout and capillary electrophoresis detection. In these systems, fluorescence separation from background noise is necessary. In this paper, two methods of fluorescence separation were investigated. One adopts a total reflection mirror with a hole at the center; the other uses a dichroic mirror. For dichroic mirror system, fluorescence could transmit through the filter or be reflected by it. Signal to noise ratio depends on dichroic mirror transmitting spectra and reflecting spectra. For center hole mirror system, partial fluorescence loses during propagating through the center hole directly. Detected fluorescence is the part that reflected by the mirror outside the center hole. Size of the hole in the mirror must be changed in different systems. Performance of system with an f-theta lens as scanning lens for laser focus and fluorescence collecting was simulated. Collinear systems with above-mentioned two methods were set up and compared. Simulated results were verified by experiments.

Date Published: 29 November 2007
PDF: 5 pages
Proc. SPIE 6722, 3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, 672215 (29 November 2007); doi: 10.1117/12.782959

Published in SPIE Proceedings Vol. 6722:
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies
Li Yang; Yaolong Chen; Ernst-Bernhard Kley; Rongbin Li, Editor(s)