Application of autofocusing methods in continuous-wave terahertz in-line digital holography

Huang, Haochong; Wang, Dayong; Rong, Lü; Zhou, Xun; Li, Zeyu; Wang, Yunxin

doi:10.1016/j.optcom.2015.01.077

Cited by 27 publications

(6 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As can be seen, the contrast of the hologram is degraded when the PTFE plate is presented because of the inhomogeneity of the covered mask. An autofocus algorithm 27 was applied to determine the reconstructed distance. The distance was 63.0 mm in the uncovered case and 63.65 mm in the covered case because of the optical path difference caused by the different refractive index of the air and PTFE.…”

Section: Reconstructed Results Of the Single Hologrammentioning

confidence: 99%

Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography

et al. 2019

Self Cite

View full text Add to dashboard Cite

Terahertz waves have unique propagation and penetration ability, and these reasons have been widely used in nondestructive testing. Compared with other terahertz imaging approaches, terahertz digital holography can retrieve both quantitative amplitude and phase information about an object wavefront in real time. A continuous-wave terahertz reflective digital holographic method is proposed for measuring the profile of covered objects. Subpixel image registration and image fusion algorithms are presented to expand the field-ofview (FOV) of the system. The validity of the proposed method is verified by the experiment using an optical pumped far-IR gas laser and a pyroelectric array detector. The profile of a metallic bookmark covered by a polytetrafluoroethylene plate is obtained. The FOV is expanded by a factor of 1.75 compared with that of a reconstruction performed employing single hologram.

show abstract

Section: Reconstructed Results Of the Single Hologrammentioning

confidence: 99%

Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is mandatory that an appropriate propagation distance is estimated before reconstructing the focused sample distribution. In other words, the focused sample has clearly defined edge information [26]. Therefore, in order to estimate the edges, in our simulations, the Laplacian of Gaussian (LoG) filter is employed.…”

Section: Methodsmentioning

confidence: 99%

Sparsity based terahertz reflective off-axis digital holography

et al. 2017

Self Cite

View full text Add to dashboard Cite

“…Chen et al developed a denoising method for THz in-line digital holographic reconstructions, based on a Markov chain Monte Carlo sampling [151]. Different auto-focusing algorithms and corrections were investigated by Huang et al [125,127] and applied to reconstruct a pair of objects at different distances from the detector [121].…”

Section: In-line Digital Holographymentioning

confidence: 99%

THz coherent lensless imaging

et al. 2019

Self Cite

View full text Add to dashboard Cite

Imaging with THz radiation has proved an important tool for both fundamental science and industrial use. Here we review a class of THz imaging implementations, named coherent lensless imaging, that reconstruct the coherent response of arbitrary samples with a minimized experimental setup based only on a coherent source and a camera. After discussing the appropriate sources and detectors to perform them, we detail the fundamental principles and implementations of THz digital holography and phase retrieval. These techniques owe a lot to imaging with different wavelengths, yet innovative concepts are also being developed in the THz range and are ready to be applied in other spectral ranges. This makes our review useful for both the THz and imaging communities, and we hope it will foster their interaction.

show abstract

Application of autofocusing methods in continuous-wave terahertz in-line digital holography

Cited by 27 publications

References 25 publications

Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography

Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography

Sparsity based terahertz reflective off-axis digital holography

THz coherent lensless imaging

Contact Info

Product

Resources

About