An apparatus for detecting images in a first selected bandwidth includes a probe light source to generate a probe beam in a second selected bandwidth, an optical path including input imaging optics to capture an image in the first selected bandwidth and form an image beam and a beam combiner to optically combine the probe beam with the image beam to form a combined beam, and an optical readout quantum well device in the optical path of the combined beam, which simultaneously passes in an optical readout beam an intensity level of at least one wavelength within the probe beam in the second selected bandwidth in proportion to an intensity level of at least one wavelength within the image beam in the first selected bandwidth; and a detector sensitive to light in the second selected bandwidth and not sensitive to light in the first selected bandwidth.