A photorefractive novelty filter module for commercial microscope systems: Design, development and applications.

Photorefractive novelty filter, when combined with a conventional microscope, is a versatile device for real-time motion detection and quantitative phase measurement. The enormous potential of this system to measure optical phase changes as small as l/20 (at 532 nm) makes it an ideal device for real-time observation and diagnosis of live biological systems and dynamic fluid flows. In this contribution, we demonstrate and discuss the design and development of a compact and robust novelty filter module integrated in a commercial microscope system. We present the highlights of this module with special emphasis on the universality of the design and the compatibility of the device for the investigation of extremely sensitive biological systems. With the help of videos, we demonstrate the applicability of this microscope system in the fields of fluid dynamics and biology. We present examples of the study of fluid flow properties and fluid mixing in micro-channels - one of the basic building blocks of the lab-on-a-chip paradigm. We also show the exemplary results of the observation and study of micro-currents generated by microorganisms used in sewage water-cleaning plants. This novelty filter module, with its beneficial assets of real-time phase-to-intensity conversion and large contrast enhancement, has all the potential to become the choice for the investigation of dynamic processes in micro- and nano-scale regimes.