Juskaitis, R., Wilson, T., Neil, M. A. A. and Kozubek, M.
Efficient real-time confocal microscoy with white light sources. Nature 383: 804-806 (1996).

The main advantage of confocal microscopes over their conventional counterparts arises from their ability to optically 'section' nearly transparent materials; the thin image slices thus obtained can be used to reconstruct three-dimensional images, a capability which is particularly useful for the study of biological specimens. Confocal microscopes have previously used either a single laserilluminated point-source and single point-detector (which are scanned in tandem across the object) or white-light illumination with multiple point-sources and detectors. Single-point-source systems, however, do not usually form images in real time and are restricted to using available laser wavelengths. Multiple-point-source systems, on the other hand, produce images in real time but use light very inefficiently-typically 1% or less is used for imaging. Here we demonstrate a white-light, multiple-pointsource method which can in principle produce images in real time with light efficiencies as high as 50%. This system is likely to find broad practical application, particularly in the imaging of weakly reflecting or weakly fluorescent specimens.