Multimodal optical microscope for imaging biological samples

A multimodal microscope provides a researcher with the ability to capture images with multiple sources of contrast. Previous attempts at multimodal microscopy have been limited to capturing images at different instruments and digitally registering the images empirically using features common in the specimen. Other multimodal microscopes have combined different microscopy techniques, but have been limited in their sources of contrast. We present a unique microscope which contains 5 different imaging modalities, with four different sources of contrast. Quadrature microscopy measures the phase of the electric field of the light transmitted through an optically transparent specimen, by interference with a reference beam, using a polarimetric technique to resolve the ambiguities between phase and amplitude. Differential Interference Contrast (DIC) measures the phase gradient in an optically transparent specimen by combining two spatially separated images interferometrically. Confocal reflectance measures index of refraction changes in a plane or reflection from small scatterers. Confocal fluorescence and 2-photon laser scanning microscopy, measure fluorescent signatures of a specimen. The last three of these are inherently capable of producing three-dimensional images directly, through localized probing.