Scatter-plate microscopy with spatially coherent illumination and temporal scatter modulation

Ludwig, Stephan; Ruchka, Pavel; Pedrini, Giancarlo; Peng, Xiang

doi:10.1364/oe.412047

Cited by 10 publications

(3 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This causes speckle to be generated and evaluated at the imaging plane. To overcome this, structured illumination using a rotating diffuser [18,19] can be used to investigate objects with smooth surfaces. In the following, two measurement scenarios will be discussed, one for the extreme case where NA ill > NA img , indicating no speckle contrast, and the second for NA ill = NA img .…”

Section: Increasing the Illumination Aperturementioning

confidence: 99%

Extended-Aperture Shape Measurements Using Spatially Partially Coherent Illumination (ExASPICE)

Agour,

Falldorf,

Bergmann

2024

Sensors

View full text Add to dashboard Cite

We have recently demonstrated that the 3D shape of micro-parts can be measured using LED illumination based on speckle contrast evaluation in the recently developed SPICE profilometry (shape measurements based on imaging with spatially partially coherent illumination). The main advantage of SPICE is its improved robustness and measurement speed compared to confocal or white light interferometry. The limited spatial coherence of the LED illumination is used for depth discrimination. An electrically tunable lens in a 4f-configuration is used for fast depth scanning without mechanically moving parts. The approach is efficient, takes less than a second to capture required images, is eye-safe and offers a depth of focus of a few millimeters. However, SPICE’s main limitation is its assumption of a small illumination aperture. Such a small illumination aperture affects the axial scan resolution, which dominates the measurement uncertainty. In this paper, we propose a novel method to overcome the aperture angle limitation of SPICE by illuminating the object from different directions with several independent LED sources. This approach reduces the full width at half maximum of the contrast envelope to one-eighth, resulting in a twofold improvement in measurement accuracy. As a proof of concept, shape measurements of various metal objects are presented.

show abstract

Section: Increasing the Illumination Aperturementioning

confidence: 99%

Extended-Aperture Shape Measurements Using Spatially Partially Coherent Illumination (ExASPICE)

Agour,

Falldorf,

Bergmann

2024

Sensors

View full text Add to dashboard Cite

show abstract

“…The SCCI method can reconstruct the hidden object image without iteration by introducing a reference point. In recent years, the SCCI method has been proven to be suitable for both coherent and incoherent systems in microscopy [30], 3D imaging [31], and target localization [7]. In SCCI, when the object and reference point are strictly coplanar, the object image with high resolution can be reconstructed, thus possessing the ability of depth resolution.…”

Section: Introductionmentioning

confidence: 99%

Depth-resolved imaging through dynamic scattering media via speckle cross-correlation under near-infrared illumination

Wang,

Zhou,

Zhang

et al. 2024

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Speckle cross-correlation imaging (SCCI) method has the depth-resolved capability, benefiting from the introduction of a reference point. However, the quality of the reconstructed image is degraded due to the background noise, which becomes more prominent when imaging through dynamic scattering media. Here, we propose a composite-differential filter-assisted (CDF-SCCI) method, allowing for effectively reducing the background noise of the reconstructed image. The signal-to-background ratios of the reconstructed images by employing the CDF-SCCI method can be enhanced by a maximum of 4.15 dB (corresponding to 2.6 times) compared to the SCCI method. Furthermore, we apply the near-infrared (NIR) illumination to the imaging system of dynamic scattering media and prove that the NIR illumination not only enhances the penetration depth of imaging, but also improves the quality of reconstructed images compared to the visible illumination. The depth-resolved imaging through various dynamic biological scattering media, including the milk and anticoagulated pig blood, further demonstrates the potential application of the proposed CDF-SCCI method in biomedical imaging.

show abstract

“…To reconstruct the object information from the captured Send correspondence to Tom Glosemeyer: tom.glosemeyer@tu-dresden.de speckle pattern, different techniques based on speckle correlation for imaging through scattering media exploiting the optical memory effect were proposed. [22][23][24][25][26][27][28] However, these algorithms are too slow for a real-time application and rely on a strong memory effect. Neural Networks have demonstrated the ability to decode objects from speckle patterns fast even without a strong memory effect.…”

Section: Introductionmentioning

confidence: 99%

Step-by-step transfer function reversal for single-shot 3D fiber endoscopy using a diffuser

Glosemeyer

Lich

Kuschmierz

et al. 2023

Three-Dimensional and Multidimensional Microscopy: Image Acquisition and Processing XXX

View full text Add to dashboard Cite

Endoscopy through coherent fiber bundles plays a significant role in industrial and medical 2D imaging. By replacing the lens on the distal side with a diffuser, the 3D information of the measurement volume is encoded as 2D speckle patterns on the camera. Neural Networks can then be employed to reconstruct the 3D object. Therefore, minimally invasive single-shot 3D imaging through a flexible low-cost endoscope with a diameter of less than 1 mm is enabled. However, the number of fiber cores is limiting the transferable information and reduces the reconstruction quality. In this paper, separate reconstruction for the diffuser and the coherent fiber bundle for different core numbers is explored. This approach enables biomedical applications for in vivo diagnostics, e.g. with fluorescence imaging in 3D.

show abstract

Scatter-plate microscopy with spatially coherent illumination and temporal scatter modulation

Cited by 10 publications

References 15 publications

Extended-Aperture Shape Measurements Using Spatially Partially Coherent Illumination (ExASPICE)

Extended-Aperture Shape Measurements Using Spatially Partially Coherent Illumination (ExASPICE)

Depth-resolved imaging through dynamic scattering media via speckle cross-correlation under near-infrared illumination

Step-by-step transfer function reversal for single-shot 3D fiber endoscopy using a diffuser

Contact Info

Product

Resources

About