Most 3D microscopes use multiple lenses or cameras that move around an object. A new lens created by Allen Yi and colleagues, Ohio State University, USA, is the first single, stationary lens to create microscopic 3D images.

The freeform lens was milled on a precision cutting machine which shaved the lens in increments of 10 nm. The prototype was made of polymethyl methacrylate and resembled a cut gemstone, with a faceted top and a wide, flat bottom. It was installed in a microscope with a camera positioned to look through the faceted side. Each facet captured an image from a different angle, which could be used to generate a 3D computer image.

The team hope to adapt the lens for use with liquid samples and note that the new lens is compatible with microscopes already in use.

Photo by Kevin Fitzsimons, courtesy of Ohio State University

• Design and fabrication of a freeform prism array for 3D microscopy
  L. Li, A. Y. Yi,
  J. Opt. Soc. Am. A 2010, 27, 2613–2620.
  DOI: 10.1364/JOSAA.27.002613