SINGLE-PINHOLE CONFOCAL DIFFERENTIAL PHASE-CONTRAST MICROSCOPY

A new technique for obtaining confocal differential phase contrast is outlined. It is shown that this method involving a single pinhole and a split detector is easier to align and calibrate than the standard me thod of two pinholes and two detectors. Experimental calibration curve s, which show that this arrangement does perform differential phase co ntrast imaging and that it can be used to measure surface height varia tions of the order of lambda/600 per micrometer, are presented. Confoc al scanning-beam reflection and transmission differential phase contra st images are presented.