Miniature wide angle lens under development at UCSD

Sep 27, 2013 at 21:40 GMT

Researchers at UCSD's Jacobs School of Engineering are working on a miniature wide angle lens by taking advantage of the benefits of spherical lenses. At just a tenth of the size of a traditional wide angle lens, a spherical lens can create wide angle images without chromatic aberration or loss of resolution at corners. The challenge is capturing the lens' spherical projection on a flat sensor. The team have overcome this by using optical fibers fused to the rear of the lens to relay light to electronic sensors.

Researchers were initially concerned that focusing the lens would require the optical fibers to move back and forth, but found that the system boasts large enough depth of field that movement wasn't necessary. Early tests suggest the lens is capable of rendering images of very high resolution - 0.2 milliradian. That translates to 0.011 degrees resolution, or around 7800 lines per height. 

A prototype lens from UCSD's engineering school. The miniature lens is one tenth of the size of the Canon EF 8-15mm f/4L pictured beside it, yet would boast a resolving power of 0.2 milliradian. However, because of its use of optical fibers and monocentric lens, it's not likely to be used in an interchangeable lens system.

The project's engineers describe the design as using monocentric lenses with a bundle of glass optical fibers aligned to the lens' surface in order to relay the light collected by the lens to electronic sensors. Thanks to the lens' spherical design, resolution is (in theory) the same across the image field, making possible a kind of 'zooming without moving parts' anywhere in the field of view without encountering loss of resolution or off-axis lens aberrations.

The UCSD team is currently working with a design for a 12mm focal length with a 5 megapixel sensor and a 30 megapixel prototype. Next, they're hoping to build a system giving an 85 megapixel image.

It seems unlikely that this kind of optical system would be used by smartphones as the school's press release suggests, and more likely that its 'pan and zoom with no moving parts' capabilities would be put to use in surveillance equipment. The project's DARPA funding suggests that the lens will find a home in military applications, where a very wide angle of view rendered without a loss of resolution would be genuinely useful. It probably won't appear on a camera near you anytime soon, but it's an interesting proof of concept.