Scanning heterodyne confocal differential phase and intensity microscope

The construction and results obtained with a scanning heterodyne differential microscope capable of simultaneously imaging in differential phase and differential intensity modes are described. Interfering the two signal beams with a common reference beam (indirect interference) permits an optimum differential phase and intensity performance to be obtained simultaneously. The considerations that ensure satisfactory performance are discussed. Results that demonstrate the ability to alter electronically the imaging mode and the optical transfer function within each imaging mode are presented. This permits the system performance to be matched to the requirements of each sample.