Integration of hybrid optical filter with Buried Quad pn-Junction photodetector for multi-labeling fluorescence detection applications

We present a hybrid optical filter combining interference and absorbing filtering approaches for enhanced-performance fluorescence detection systems. The filter is fabricated in a CMOS compatible process for monolithic integration with a CMOS photodetector. The rejection of fluorescence emission at 532 nm compared to 650 nm is over 43 dB. The CMOS photodetector can be a BMJ (Buried Multiple-pn-Junction) structure for both photodetection and spectral discrimination. Employing a CMOS Buried Quad pn-Junction (BQJ) detector, multi-labeling spectral contributions of fluorescence emission can be determined (for cases up to 4 tags).