A Fresnel lens is a lens that works like a convex lens, but which eliminates the bulk of such a lens by the use of a series of angled steps in the front surface of an otherwise flat sheet of glass or plastic. The steps are angled in such a way as to concentrate light at the focus.
Recent news and developments
- December 2012: Bernhard Müller has published findings based on his experimentation with a twin Fresnel lens reflector solar cooker. This cooker was never meant to be a production prototype, and his company, Mueller Solartechnik, no longer manufactures solar cookers. As an engineering exercise, he has shown that incorporating the Fresnel lens produces quite high temperatures(278.6°C/534°F). However, the usable cooking area is small. Read more: Twin Fresnel Cooker
Audio and video
- Designing a fresnel lens and mirror solar cooker - rimstar.org