Publication detail

The Role of Coherence in Image Formation in Holographic Microscopy

CHMELÍK, R. SLABÁ, M. KOLLÁROVÁ, V. SLABÝ, T. LOŠŤÁK, M. ČOLLÁKOVÁ, J. DOSTÁL, Z.

Original Title

The Role of Coherence in Image Formation in Holographic Microscopy

English Title

The Role of Coherence in Image Formation in Holographic Microscopy

Type

journal article in Web of Science

Language

en

Original Abstract

Off-axis digital holographic microscopes (DHM) working with incoherent light have been designed and constructed. Their imaging properties can be changed by variation of the coherence of light. This spans from emulation of classic coherent-light DHM allowing for numerical focusing to incoherent-light DHM characterized by high-quality imaging, no coherence noise, halved limit of lateral resolution, and by coherence-gating effect making imaging in turbid media and optical sectioning possible. We describe theoretically the imaging process of a holographic microscope (HM) and how it is influenced by the coherence of illumination. The 3D coherent transfer function (CTF) reveals the dependence of a spatial frequency passband on the coherence properties of a source. Reduction of coherence leads to the passband broadening i.e. to the resolution enhancement. This effect is obvious also from the form of 3D point spread functions, which allows us to characterize imaging by 3D convolution. Imaging and numerical focusing of planar objects are described by 2D CTF derived from 3D CTF for various defocusing. Results for 2D objects are presented also in a simplified approximate form, which gives deeper insight into the fundaments of imaging. In this approximation, the image formation in a turbid medium by coherence gating is elucidated. In addition, it is shown that the mutual lateral shift of the object and reference beams amplifies higher spatial frequencies of a defocused object and allows an object in a turbid medium to be imaged by diffuse (non-ballistic) light. Important theoretical results are verified experimentally.

English abstract

Off-axis digital holographic microscopes (DHM) working with incoherent light have been designed and constructed. Their imaging properties can be changed by variation of the coherence of light. This spans from emulation of classic coherent-light DHM allowing for numerical focusing to incoherent-light DHM characterized by high-quality imaging, no coherence noise, halved limit of lateral resolution, and by coherence-gating effect making imaging in turbid media and optical sectioning possible. We describe theoretically the imaging process of a holographic microscope (HM) and how it is influenced by the coherence of illumination. The 3D coherent transfer function (CTF) reveals the dependence of a spatial frequency passband on the coherence properties of a source. Reduction of coherence leads to the passband broadening i.e. to the resolution enhancement. This effect is obvious also from the form of 3D point spread functions, which allows us to characterize imaging by 3D convolution. Imaging and numerical focusing of planar objects are described by 2D CTF derived from 3D CTF for various defocusing. Results for 2D objects are presented also in a simplified approximate form, which gives deeper insight into the fundaments of imaging. In this approximation, the image formation in a turbid medium by coherence gating is elucidated. In addition, it is shown that the mutual lateral shift of the object and reference beams amplifies higher spatial frequencies of a defocused object and allows an object in a turbid medium to be imaged by diffuse (non-ballistic) light. Important theoretical results are verified experimentally.

Keywords

Digital holographic microscopy; Off-axis holography; Coherence of light; Coherent transfer function; Point spread function; Numerical focusing; Imaging in turbid media; Coherence gating; Quantitative phase imaging

RIV year

2014

Released

19.05.2014

Publisher

Elsevier Academic Press

Location

San Diego, CA, USA

ISBN

0079-6638

Periodical

PROGRESS IN OPTICS

Year of study

59

Number

1

State

NL

Pages from

267

Pages to

336

Pages count

70

Documents

BibTex


@article{BUT107549,
  author="Radim {Chmelík} and Michala {Slabá} and Věra {Kollárová} and Tomáš {Slabý} and Martin {Lošťák} and Jana {Čolláková} and Zbyněk {Dostál}",
  title="The Role of Coherence in Image Formation in Holographic Microscopy",
  annote="Off-axis digital holographic microscopes (DHM) working with incoherent light have been designed and constructed. Their imaging properties can be changed by variation of the coherence of light. This spans from emulation of classic coherent-light DHM allowing for numerical focusing to incoherent-light DHM characterized by high-quality imaging, no coherence noise, halved limit of lateral resolution, and by coherence-gating effect making imaging in turbid media and optical sectioning possible. We describe theoretically the imaging process of a holographic microscope (HM) and how it is influenced by the coherence of illumination. The 3D coherent transfer function (CTF) reveals the dependence of a spatial frequency passband on the coherence properties of a source. Reduction of coherence leads to the passband broadening i.e. to the resolution enhancement. This effect is obvious also from the form of 3D point spread functions, which allows us to characterize imaging by 3D convolution. Imaging and numerical focusing of planar objects are described by 2D CTF derived from 3D CTF for various defocusing. Results for 2D objects are presented also in a simplified approximate form, which gives deeper insight into the fundaments of imaging. In this approximation, the image formation in a turbid medium by coherence gating is elucidated. In addition, it is shown that the mutual lateral shift of the object and reference beams amplifies higher spatial frequencies of a defocused object and allows an object in a turbid medium to be imaged by diffuse (non-ballistic) light. Important theoretical results are verified experimentally.",
  address="Elsevier Academic Press",
  chapter="107549",
  doi="10.1016/B978-0-444-63379-8.00005-2",
  institution="Elsevier Academic Press",
  number="1",
  volume="59",
  year="2014",
  month="may",
  pages="267--336",
  publisher="Elsevier Academic Press",
  type="journal article in Web of Science"
}