Dynamic quantitative phase microscopy: a single-shot approach using geometric phase interferometry

There is a significant gap in cost-effective quantitative phase microscopy (QPM) systems for studying dynamic cellular processes while maintaining accuracy for long-term cellular monitoring. Current QPM systems often rely on complex and expensive voltage-controllable components like Spatial Light Modulators or two-beam interferometry. To address this, we introduce a QPM system optimized for time-varying phase samples using azobenzene liquid crystal as a Zernike filter with a polarization-sensing camera. This system operates without input voltage or moving components, reducing complexity and cost. Optimized for gentle illumination to minimize phototoxicity, it achieves a 1 Hz frame rate for prolonged monitoring. The system demonstrated accuracy with a maximum standard deviation of +/- 42 nm and low noise fluctuations of +/- 2.5 nm. Designed for simplicity and single-shot operations, our QPM system is efficient, robust, and precisely calibrated for reliable measurements. Using inexpensive optical components, it offers an economical solution for long-term, noninvasive biological monitoring and research applications. Current quantitative phase microscopy (QPM) systems to study dynamic cellular processes are often expensive and complex. The authors develop a cost-effective QPM system using azobenzene liquid crystals, which operate without input voltage or moving parts. This system achieves accurate, low-noise measurements and is ideal for dynamic and non-invasive biological monitoring.