SBIR-STTR Award

Two design approaches have been taken in the design of a compact infrared zoom lens to operate in the 3 to 5 micron spectral band, with an aperture of f/4.5: an overall length of less than 150 mm, and a diameter of 75 mm. The zoom range is to be 4X, with focal lengths from 50 to 200 mm and angular field coverages from 5 to 20 degrees. The first approach is the design of an advanced Mechanically Compensated IR Zoom Lens. This design based on prior COI 4X zoom lenses offers the most direct engineering design solution. The second approach is the development of an Optically Compensated IR Zoom Lens. This design concept has the potential of many advantages since it has only one moving part, and offers a simpler and lighter lens construction with greater reliability. A detailed optical tolerance analysis will be carried out for both types, including the effects of all element thicknesses and separations; as well as thermal effects and manufacturability.

In Phase I, an Optically compensated infrared Zoom (CIZ) Munitions Lens using aspheric elements was designed which combines high quality optical performance with a compact, rugged, lightweight mechanical mechanism consisting of only one moving part. The Aspherized Optically Compensated CIZ, is designed to operate in the 3 to 5 micron spectral band with an aperature of less than f/3.5, a length less than 150 mm with a 4X zoom range covering focal lengths from 50 to 200 mm and a singular field of 5 to 20 degrees. This Phase II program is to complete the optical and mechanical engineering for the Aspherized Optically Compensated CIZ and manufacture two prototype lenses. The Phase II work will include the design and manufacture of all the optics, motion control hardware and mechanics for the lenses. The prototype will be assembled, aligned, and tested to evaluate their optical performance at selected points that span the full field of view from wide angle to narrow angle which is the entire 4X Zoom range of 50 to 200mm. Military environmental tests will be conducted on a prototype for shock, vibration, temperature, humidity and altitude to verify the structural integrity of the one moving part mechanical design.

Benefits:
Improved flight trajectory and more accurate terminal guidance of munitions. Guidance of manned and unmanned space vehicles. Potential use in industrial machine vision, law enforcement and automation systems.

Keywords:
IR ZOOM COMPACT OPTICALLY COMPENSATED ASHPERIC ZOOM