An easy-to-build long working distance microscope

In order to obtain sharp images of objects inside an optical cryostat, we have designed a microscope with all optical elements outside the cryostat. This microscope resolves 2 mu m at a working distance of 20 cm. It is easy to build and not expensive, as only standard components are used except for one single lens. (C) 2000 Elsevier Science B.V. All rights reserved.