A MEMS-less infrared pyroelectric sensor that employs an active detection mechanism based on a strontium bismuth tantalate (SrBi2Ta2O9) ferroelectric sensing material is described and compared to passive modes of operation. A model is based on fundamental performance of ferroelectrics in which the polarization state of the material is actively interrogated enabling improved signal to noise ratio, greater effective pyroelectric coefficient, and chopper-less design. In addition to excellent thermal responsivity in the medium and long wavelength bands and unlimited endurance, the unique design enables selective wavelength tuning of insulating layer and absorber materials to maximize the responsivity at distinct wavelengths.