Harmonically decoupled gradient light interference microscopy (HD-GLIM)

Abstract

Differential phase sensitive methods, such as Nomarski microscopy, play an important role in quantitative phase imaging due to their compatibility with partially coherent illumination and excellent optical sectioning ability. In this Letter, we propose a new system, to the best of our knowledge, to retrieve differential phase information from transparent samples. It is based on a 4f optical system with an amplitude-type spatial light modulator (SLM), which removes the need for traditional differential interference contrast (DIC) optics and specialized phase-only SLMs. We demonstrate the principle of harmonically decoupled gradient light interference microscopy using standard samples, as well as static and dynamic biospecimens.

Fig. 1.

Schematic demonstration of HD-GLIM system. Four phase-shifted patterns with Δδ = π/2 are added on the SLM.

Fig. 2.

(a) Phase distribution of 4.5 μm polymetric microbeads. (b) Simulation and measurement data.

Fig. 3.

(a) and (b) Spatiotemporal noise distribution with log operation at k_x = 0 and k_x = π. (c) Spatial noise distribution. (d) Temporal phase fluctuation of the point marked in (c). Color bar in (a) and (b) is rad²/[rad/ μm]² [rad/s].

Fig. 4.

(a)-(d) Four differential interference data used for phase demodulation. (e)-(f) Phase of CW620 cells and its corresponding details.

Fig. 5.

(a)-(d) Four differential interference data used for phase demodulation. (e)-(g) Phase of pancreas tissue and its different details.

Fig. 6.

(a) and (b) Phase results under NAc = 0.09. (c) and (d) are the phase results under NAc = 0.55.