Intensity and Phase correction Enhanced interferometric scattering microscopy (iSCAT)

TL;DR

This paper develops a model for contrast and phase modulation in interferometric scattering microscopy with oblique illumination, enabling enhanced contrast measurement and providing new insights into contrast improvement techniques.

Contribution

The authors establish a novel model for contrast and phase modulation in iSCAT microscopy and demonstrate a calibration method for uniform contrast measurement without rotation.

Findings

Contrast enhancement verified with oblique illumination

Phase map calibration enables uniform contrast measurement

Model provides new insights into contrast and phase modulation

Abstract

Interferometric scattering microscopy was widely applied in nanoscopic detection and tracking due to its high sensitivity and label-free manner. The sensitivity is limited by contrast. Oblique illumination provided high contrast with lower power density. However, no model has been established to illustrate the schematic and complex rotation setup was needed. Here, we established a model of contrast and the unexpected reflections both in intensity and phase modulation. Then, the contrast enhancement was verified in oblique illumination. To provide a uniform contrast measurement, the phase map of oblique illumination was calibrated through scanning without the need for rotation. Our work gives new insights in oblique illumination and may inspire new idea to enhance contrast with phase and intensity modulation.