Sparsity-based continuous wave terahertz lens-free on-chip holography with sub-wavelength resolution

Li, Zeyu; Yan, Qiang; Qin, Yu; Kong, Weipeng; Li, Guangbin; Zou, Mingrui; Wang, Du; Zhou, You; Zhou, Xun

doi:10.1364/oe.27.000702

Cited by 22 publications

(6 citation statements)

References 27 publications

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“…The basic outline of the dehydrated mosquito could be observed in the reconstructed images. In 2019, Li et al further modified the in-line CW THD system based on a 4.3 THz QCL and a microbolometer detector [64,65]. Both the synthetic aperture algorithm and shortening the distance together can improve the resolution.…”

Section: Cw Thz Digital Holographymentioning

confidence: 99%

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Continuous-Wave THz Imaging for Biomedical Samples

et al. 2020

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In the past few decades, the applications of terahertz (THz) spectroscopy and imaging technology have seen significant developments in the fields of biology, medical diagnosis, food safety, and nondestructive testing. Label-free diagnosis of malignant tumours has been obtained and also achieved significant development in THz biomedical imaging. This review mainly presents the research status and prospects of several common continuous-wave (CW) THz medical imaging systems and applications of THz medical imaging in biological tissues. Here, we first introduce the properties of THz waves and how these properties play a role in biomedical imaging. Then, we analyse both the advantages and disadvantages of the CW THz imaging methods and the progress of these methods in THz biomedical imaging in recent ten years. Finally, we summarise the obstacles in the way of the application of THz bio-imaging application technology in clinical detection, which need to be investigated and overcome in the future.

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Section: Cw Thz Digital Holographymentioning

confidence: 99%

“…The profile characteristics and relative optical thickness distribution of the asparagus fern were obtained by unwrapped phase'images. 3 THz QCL and a microbolometer detector [64,65]. Both the synthetic aperture algorithm and shortening the distance together can improve the resolution.…”

Section: Cw Thz Digital Holographymentioning

confidence: 99%

Continuous-Wave THz Imaging for Biomedical Samples

et al. 2020

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“…This implies a large overlap between consecutive images, leading to an increase of the signal-to-noise ratio as high as ffiffiffiffiffiffiffi ffi N xy p in the pixels measured N xy times. As an additional benefit, such shifts allow us to average out diffraction effects associated with optics and camera edges, which are often an issue when imaging with coherent THz radiation [21].…”

Section: N Xymentioning

confidence: 99%

Coherent reconstruction of a textile and a hidden object with terahertz radiation

Valzania

Zolliker

Hack

2019

Optica

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Imaging through scattering materials is of utmost importance, especially for security and biomedical imaging. Unlike the rest of the electromagnetic spectrum, terahertz radiation is a non-ionizing probe and allows imaging deep through non-conducting materials with sub-millimeter resolution. Here, we propose a coherent imaging technique reconstructing two objects, hidden one behind the other, from relative shifts between them. Experimental reconstructions at λ 96.5 μm of amplitude and phase objects hidden behind a glass fabric sample are presented. The hidden objects are retrieved with a lateral resolution of ≈1.5λ and a depth resolution of ≈λ∕10. Besides envisioning its use in noninvasive imaging, we anticipate that, in selected applications, the suggested approach can replace a similar phase retrieval technique, namely ptychography.

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“…Microbolometers have been intensively applied for long-wave infrared coherent imaging [81]. Interestingly, the microbolometers designed for the wavelength range 8-14 µm possess better sensitivities than THz microbolometers around 100 µm [82] and thus have become the cameras of choice for lensless imaging applications [35,36,[83][84][85][86][87]. Notice that, however, care should be taken because their pixels are venerable to dazzling or permanent damage caused by a low-power (several µW) laser focused on several pixels.…”

Section: Thz Detectorsmentioning

confidence: 99%

“…Recently, Li et al reported a resolution of 0.7λ adding a L 1 -sparsity constraint to the support constraint at the object plane [87]. Further strategies for the correction of experimental inaccuracies were reported.…”

Section: In-line Digital Holographymentioning

confidence: 99%

THz coherent lensless imaging

et al. 2019

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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.

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Sparsity-based continuous wave terahertz lens-free on-chip holography with sub-wavelength resolution

Cited by 22 publications

References 27 publications

Continuous-Wave THz Imaging for Biomedical Samples

Continuous-Wave THz Imaging for Biomedical Samples

Coherent reconstruction of a textile and a hidden object with terahertz radiation

THz coherent lensless imaging

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