Patent ID: 11921284
Assignee: RAYTHEON COMPANY
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 12:
13. An afocal zoom system, comprising:
a collection optic having a first focal length f1, said collection optic configured to collect a beam of light;
a reflective Fresnel Lens having a second variable focal length f2 configured to alter a width of the beam of light by a magnification M=f2/f1; and
a mechanism responsive to position signals configured to translate the reflective Fresnel lens to maintain a spacing d between the collection optic and the reflective Fresnel lens of d=f1+f2
said reflective Fresnel Lens comprising a Micro-Electro-Mechanical System (MEMS) Micro-Mirror Array (MMA) including a plurality of mirrors, said MEMS MMA responsive to command signals to tip, tilt and piston the mirrors in three degree-of-freedom (DOF) to form a center region surrounded by a plurality of concentric rings whose reflective surfaces as formed by the mirrors approximate respective curvatures to focus light at a common focal point to set the second variable focal length f2 and magnification M.