A Low noise CMOS image sensor with an emission filter for fluorescence applications

This paper presents a 128x128 low noise CMOS image sensor with emission filter for fluorescence detection. The imager, fabricated in 0.18 mum CMOS technology, provides low- noise operation by employing both the active reset (AR) technique and the active column sensor (ACS) readout method. The emission filter was fabricated using PDMS and Sudan II Blue dye mixed, spin-coated and deposited in the class 1000 clean room. The designed filter is suitable for excitation at wavelengths below 340 nm and emission at 450nm and above. Filter properties, such as thickness, transmission and efficiency of utilization with the fabricated imager are discussed. Preliminary measurements of the system using microbeads are also presented.