Dual Field of View Annular Folded Optics with Switchable Mirrored Surface

A compact narrow field-of-view optical imaging method capable of electrically switching to a wide field of view, the compact narrow field-of-view optical imaging method comprising:

• imaging a distant object through a narrow field-of-view annular window having an aperture stop with a defining stop annulus;
• reflecting said narrow field-of-view image through annular folded optics comprising three annular mirrored surfaces arranged in an annular configuration concentric with the stop annulus;
• and
• transmitting said narrow field-of-view image reflected through said annular folded optics to a switchable reflective surface, wherein, when said switchable reflective surface is in a mirror state, a mirror surface gives said narrow field-of-view image a final reflection towards an image plane of a sensor array, and wherein, when said switchable reflective surface is switched to a clear alternate state, an alternate wide field-of-view image is passed through a clear surface of the switchable reflective surface and proceeds to the image plane of the sensor array.

A compact wide field-of-view optical imaging method capable of electrically switching to a narrow field of view, comprising:

• imaging a distant object through a wide field-of-view aperture stop;
• first refracting said image through a meniscus lens;
• refracting said image from said meniscus lens through a doublet lens element;
• refracting said image from said doublet lens element through the aperture of a lens having an aspheric departure on its back surface;
• refracting said image from said lens having an aspheric departure on its back surface through the aperture of a lens having a flat front surface and a curved back surface, wherein a switchable reflective surface is disposed onto the back surface of said lens having a flat front surface and a curved back surface;
• and
• focusing said image from said aperture of a lens through said switchable reflective surface towards an image plane of a sensor array when said switchable reflective surface is switched to a clear state.