Millimeter-wave optical imaging systems and methods. In one example, a mm-wave optical imaging system includes a mm-wave imaging detector located at a focal plane of the optical imaging system, an immersion lens directly coupled to the imaging detector and configured to focus the electromagnetic radiation onto the imaging detector, the immersion lens having a curved first surface and an opposing planar second surface, wherein the focal plane is located on the planar second surface and the imaging detector is directly coupled to the planar second surface, a positive power primary minor configured to reflect the electromagnetic radiation towards the immersion lens, and a Schmidt aspheric corrector configured to receive and direct the electromagnetic radiation towards the primary minor, wherein the system aperture stop is located on the Schmidt aspheric corrector.