Polarization and Spectral Interferometric Techniques for Quantitative Phase Microscopy - Biomedical Optical Phase Microscopy and Nanoscopy - page 281

side, possibly caused by the disturbance to the fiber during scanning. Yet it does not affect
the DIC image, demonstrating the excellent decoupling of gradient signal from intensity
using the spectral-domain demodulation approach and signifying one of the important
advantages of the proposed system.

Live cell dynamics were monitored by recording the DIC signal at the circled spot
( Figure 14.5A ) for 120 s with a sample rate of 83 Hz, which is limited by spectrometer data
acquisition speed. The top curves in Figure 14.5C show that two pulsatile motion events
were observed, each with a duration of 0.5 s. For comparison, a background signal was
recorded outside the cell, showing a resolution of 36 pm, which is similar to that obtained

Figure 14.5
Live cardiomyocyte measurements. (A) OPL gradient image of an isolated cardiomyocyte; double
arrow indicates shear direction. (B) Corresponding brightfield image. (C) Upper: stochastic
beating events at the circle in (A) for 2 min; inset shows enlarged view of the two beating events;
Lower: background signal taken at the upper-left corner of the image. (D) Regular beating
sequence of another cardiomyocyte shown in (E), where the bright spot indicates illuminated
location. Scale bars are 20 μ m. Source: From Ref. [23] .