Pupil plane differential detection microscopy.

ABSTRACT

Differential interference contrast (DIC) microscopy is a powerful technique for imaging phase objects in transparent samples but does not work with scattering samples. This Letter, to the best of our knowledge, describes a new technique for obtaining DIC-like phase-gradient images in scattering media based on differential detection of forward-scattered light, using detectors arranged in a ring configuration around the microscope objective pupil or its conjugate pupil plane. This method, called pupil plane differential detection (P2D2) microscopy, does not need polarization optics or a confocal pinhole, yet produces images that are free of speckles and interference noises. We compared the P2D2 imaging technique with reflectance confocal microscopy and demonstrated P2D2 as a simple add-on to conventional laser scanning microscopes.