triple band ir photodetector would require the application of at least three biases the external electronics used in conjunction with a single dual band ir photodetector or an array of photodetectors in accordance with the first embodiment can be relatively complex if an array of dual band ir photodetectors is created for use in an imager a silicon readout integrated circuit roic can be used to perform many of the required functions the roic is preferably indium bump bonded to the array of photodetectors to provide electrical thermal and mechanical connections the roic can be used to provide the two or more applied biases required to collect the excited electrons from the array of photodetectors these collected electrons will typically be used to charge a separate capacitor for each photodetector for a given integration time thereby producing a signal voltage if space permits a separate capacitor for each bias for each photodetector is preferable a separate capacitor for each bias for each photodetector reduces the memory requirements for the roic once a scene has been imaged for the integration time at each bias the resulting signal voltages are deconvolved using the stored spectral response curves the stored spectral response curves are based upon the photodetectors 39 responses under the two or more applied biases preferrably when illuminated by blackbody radiation upon deconvolution the signals for.