Flexible illumination module for lab-on-chip applications

Lab-on-chip analysis for molecular diagnostics use an analyzer unit and cartridges. Since the cartridges are disposables, their development cycle can be much shorter than the one of the analyzer unit. Hence, it is important to have a high degree of exibility in the analyzer unit to react to new cartridge developments. Our research tries to overcome limitations due to fixed interfaces by replacing a static illumination system for uorescence analysis by an adjustable module. The benefit of adjustability goes along with harder requirements. In the case of the illumination system, that means a decrease in etendue of the optical system. Purpose of the presented research is to define the spectral radiance requirements on the light source as a bottleneck in an etendue limited optical system. As light source a phosphor converted light source should be used due to the benefits of a broad spectrum. First, the concept of etendue is used to specify a theoretical spectral radiance requirement on the light source. In the second step, the best available light source is used in a prototype to measure the performance of the adjustable illumination system and to derive a practical spectral radiance requirement. ... mehrWith the currently used light source in the lab prototype, requirements are fulfilled for one out of four spectral wavelength bands. The comparison between theory and experiment shows that the theoretical requirement must be corrected by a factor of two to a practical spectral radiance requirement of about 14mW=(sr • mm2 • nm). It can be concluded that especially in the blue and red wavelength range below 500nm and over 600nm bright phosphor converted light sources are required. Since the time the light source was selected, a new light source candidate with stronger emission for shorter wavelengths was found.