A detector array of a plurality of photodetector cells is provided which operates in two spectral bands by utilizing a polarity reversing multiplexer for directly reversing the polarity of different types of photodetector pairs. More particularly, long wave photoconductive quantum well detectors and near infrared photovoltaic detectors may be advantageously interconnected to supply the two detectors with different bias voltage levels by a polarity reversal function. This polarity reversal function exploits the low and high impedance characteristics of the detectors for enhancing the electrical interconnection. As a result, the system optimally changes the operation of the detector array from one photospectral band to another to take advantage of the electrical interconnection characteristics of both devices. As a further advantage, the circuitry used may be simplified for eliminating bias lines. Thereby, the fill factor of the sensor array is increased by reducing the number of connection nodes or bumps to bias lines which provides a larger active area for the sensor array.