Optical micrograph of arrays of wavelength sized optical mirrors made from gold, each 2 µm across. They are made by growing metal around the bottom of plastic spheres, which can then be removed. A sort of casting process on the smallest scale.
This image is also available for download in the following formats:
This work is licensed under a Creative Commons Attribution-No Derivative Works 3.0 License. All image post-treatments by Andy Eccleston.