Phase-Sensitive Optical Coherence Microscopy (OCM) - Biomedical Optical Phase Microscopy and Nanoscopy - page 252

CHAPTER 13
Phase-Sensitive Optical Coherence
Microscopy (OCM)

Itay Shock and Natan T. Shaked
Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel

Editor: Zeev Zalevsky

13.1 Introduction

As previously presented in this topic, developments in quantitative phase-imaging techniques
have given insights to dynamic mechanisms in living, unstained biological cells with fast
acquisition rates and unprecedented accuracies. When measuring fluctuations in time, these
techniques can give us knowledge on physiological processes as well as pathological
conditions with subnanometric optical path delay (OPD) or optical thickness accuracy.

Optical coherence microscopy (OCM) is an imaging technique that is capable of recording
the amplitude and phase information of light that has interacted with live biological tissues
for line or point measurement [1] . By analyzing the phase information retrieved by a standard
OCM setup, it is possible to obtain quantitative OPD or optical thickness accuracy, when
measuring accuracy of several tens of picometers, at least an order of magnitude better
compared to wide-field interferometric methods such as digital holographic microscopy [2] ,
presented in the second part of the topic.

In standard OCM, the amplitude of the interference pattern is analyzed. Since the phase
oscillates 2 rad at every shift of half a wavelength of the light source, high-sensitivity phase

measurements of the fringes provide an ultrahigh-accuracy measurement of the change in the
OPD. Because of its high sensitivity to phase changes, several system designs have been
implemented to increase phase stability and reduce fluctuations due to ground vibrations, air
turbulences, acoustic noise, temperature change, and other ambient noises.

π

Section 13.2 gives a brief overview of OCM principles which is the basis of phase OCM. After
giving the basics of OCM, the section then describes how phase OCM can be derived from the
OCM data. Section 13.4 describes several phase OCM application for biomedical research.