Instantaneous polarization measurement system and method

A system for real-time imaging of retardance of a sample, comprising

• a sample region for receiving the sample;
• a source of substantially circularly polarized illumination light;
• illumination optics for directing the illumination light toward the sample region;
• analysis optics for receiving incident light from the sample region;
• a plurality of photodetector regions;
• beamsplitting optics for dividing the incident light into a plurality of sub-beams and for directing each sub-beam to a respective one of the plural photodetector regions;
• a plurality of elliptical polarizers located in the sub-beams for transmitting incident light whose polarization state lies within a distance ε of a chosen pole on a Poincare sphere;
• and
• a processor for calculating retardance from intensity signals generated at the photodetector regions onto which the sub-beams are directed;
• wherein the sample is one of a biological cell, a tissue sample, and an oocyte.

A method for imaging retardance of a sample in real-time, comprising the steps of:

• illuminating the sample with light that is substantially circularly polarized;
• receiving light that has interacted with the sample;
• dividing the received light into N sub-beams, where N≧2;
• disposing elliptical polarizers in the N sub-beams, corresponding to states within a distance ε of a pole on a Poincare sphere;
• analyzing a polarization state of each of the N sub-beams with the elliptical polarizers;
• forming an image of the sample with each sub-beam;
• measuring intensity at a plurality of points in the image at each of the N sub-beams;
• and
• calculating the sample retardance based on the N image intensity measurements.