Common-path spectral phase microscopy

Quantitative phase microscopy is an emerging non-contact method for quantifying physical properties (refractive index, thickness) of materials. The high spatial resolution achieved with millisecond-scale resolution using this non-staining method over a wide-field of view is highly advantageous for mapping dynamic changes in the sample properties due to temperature, pressure and molecular interactions. Since refractive index dispersion is intrinsic to a material, he spectral measurement of refractive index changes will allow characterization and analytical quantification of material. Here, we introduce common-path spectral phase microscopic (CP-SPM) imaging of microscopic objects. CP-SPM is based on a common path interferometer with a tunable laser beam With this method, we are able to characterize both the refractive index of particles over a continuous wavelength band, and also the characteristics of several types of particles simultaneously.