Three-dimensional analysis by a microlens-array confocal arrangement

Scanning confocal microscopy is now well developed and applied. As an alternative to a laser spot to be scanned, parallel processing can be obtained when a two-dimensional structure is moved through the focal plane and a series of image sections is recorded. Surface topography is determined by analysis of the normalized intensity of the appropriate image points, i.e., a search of the intensity maximum leads to surface coordinates. With a high numerical aperture of the optical system, the half-width of I(z) is small, and the topography can be calculated with high accuracy. But with a high numerical aperture, only small object fields can be reproduced. As an alternative to the Nipkow disk for parallel processing, high-numerical-aperture microlenses are combined in an array. The reproducible object field is then limited by the size of the array and the number of lens and detector elements.