Real-time quantitative phase measurement using a photorefractive novelty filter microscope

摘要

In this contribution, we use a novelty filter microscope for measuring transient phase changes introduced by moving phase objects and fluid flows. We describe the techniques used to eliminate contour formation and the procedures used to calibrate the filter for phase measurement. We show that, with our device, a phase resolution as low as λ/20 @ 532 nm can be achieved. We consider two practical examples to demonstrate the phase measuring capability of the device. The first example involves measurement of phase changes introduced by moving homogeneous and inhomogeneous phase objects. The second example pertains to the detection of fluid flows in microscopic scales. It demonstrates the applicability of the novelty filter microscope in the field of micro particle image velocimetry (PIV).