Assessing near infrared optical properties of ceramic orthodontic brackets using cross-polarization optical coherence tomography

Modern trends in optical bioimaging require novel nanoproducts combining high image contrast with efficient treatment capabilities. Silicon nanoparticles are a wide class of nanoobjects with tunable optical properties, which has potential as contrasting agents for fluorescence imaging and optical coherence tomography. In this paper we report on developing a novel technique for fabricating silicon nanoparticles by means of picosecond laser ablation of porous silicon films and silicon nanowire arrays in water and ethanol. Structural and optical properties of these particles were studied using scanning electron and atomic force microscopy, Raman scattering, spectrophotometry, fluorescence, and optical coherence tomography measurements. The essential features of the fabricated silicon nanoparticles are sizes smaller than 100 nm and crystalline phase presence. Effective fluorescence and light scattering of the laser-ablated silicon nanoparticles in the visible and near infrared ranges opens new prospects of their employment as contrasting agents in biophotonics, which was confirmed by pilot experiments on optical imaging.

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Low-cost semiconductor swept source laser for near-infrared Optical Coherence Tomography

2020 IEEE Photonics Conference (IPC) ◽

10.1109/ipc47351.2020.9252550 ◽

2020 ◽

Author(s):

Aritra Roy ◽

Saroj Kanta Patra ◽

Tomasz Piwonski

Keyword(s):

Optical Coherence Tomography ◽

Near Infrared ◽

Low Cost ◽

Optical Coherence ◽

Swept Source

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Coherence tomography with broad bandwidth extreme ultraviolet and soft X-ray radiation

Applied Physics B ◽

10.1007/s00340-021-07586-w ◽

2021 ◽

Vol 127 (4) ◽

Author(s):

S. Skruszewicz ◽

S. Fuchs ◽

J. J. Abel ◽

J. Nathanael ◽

J. Reinhard ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Near Infrared ◽

Extreme Ultraviolet ◽

Infrared Light ◽

Imaging Method ◽

Optical Coherence ◽

Axial Resolution ◽

Cross Sectional ◽

X Ray ◽

Broad Bandwidth

AbstractWe present an overview of recent results on optical coherence tomography with the use of extreme ultraviolet and soft X-ray radiation (XCT). XCT is a cross-sectional imaging method that has emerged as a derivative of optical coherence tomography (OCT). In contrast to OCT, which typically uses near-infrared light, XCT utilizes broad bandwidth extreme ultraviolet (XUV) and soft X-ray (SXR) radiation (Fuchs et al in Sci Rep 6:20658, 2016). As in OCT, XCT’s axial resolution only scales with the coherence length of the light source. Thus, an axial resolution down to the nanometer range can be achieved. This is an improvement of up to three orders of magnitude in comparison to OCT. XCT measures the reflected spectrum in a common-path interferometric setup to retrieve the axial structure of nanometer-sized samples. The technique has been demonstrated with broad bandwidth XUV/SXR radiation from synchrotron facilities and recently with compact laboratory-based laser-driven sources. Axial resolutions down to 2.2 nm have been achieved experimentally. XCT has potential applications in three-dimensional imaging of silicon-based semiconductors, lithography masks, and layered structures like XUV mirrors and solar cells.

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