A multi-wavelength optical imaging system and method. In one example, an optical imaging system includes an integrated dewar assembly housing a staring detector that includes a plurality of focal plane array sensors spatially distributed over a common focal plane and aligned relative to one another, each of the plurality of focal plane array sensors being configured for a different waveband. The optical imaging system further includes foreoptics, such as a telescope, optically coupled to the integrated dewar assembly and configured to direct and focus light from an entrance pupil of the optical imaging system into an optical beam incident on at least one of the plurality of focal plane array sensors.