BQJ Photodetector Signal Processing

Abstract

We propose a signal processing method for the CMOS Buried Quad Junction (BQJ) photodetector employed for multi-label fluorescence detection. It serves to quantify label components in an arbitrary mixture with improved signal-to-noise ratio. The proposed method includes least squares optimization and statistical data preprocessing based on Principal Component Analysis (PCA). The method was applied to the BQJ as well as to Buried Double Junction (BDJ) and Buried Triple Junction (BTJ) detectors. The obtained results show that BQJ case achieves best accuracy in label quantification compared to BDJ and BTJ detectors in any tested configurations. The statistical data preprocessing approach was also evaluated: 5dB SNR improvements for an example case of two-label mixture (Green-Red excitation with optical power over 28pW).