IMPROVEMENT OF AXIAL RESOLUTION IN CONFOCAL MICROSCOPY USING AN ANNULAR PUPIL

Reported in this paper arc results on the improvement in axial resolution in scanning confocal microscopy when an annular pupil is combined with a finite-sized pinhole in front of the detector. Theoretical analyses show the optimum relationship of the axial resolution to the pinhole size and the radius of central obstruction. The magnitude of the signal level is also explored. The experimental results are well in agreement with the theoretical predictions.