scholarly journals An Improved Analytical Model of a Spectrometer for Optical Coherence Tomography

Photonics ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 534
Author(s):  
Evgeny P. Sherstnev ◽  
Pavel A. Shilyagin ◽  
Dmitry A. Terpelov ◽  
Valentin M. Gelikonov ◽  
Grigory V. Gelikonov
Keyword(s):  
Experimental Data ◽  
Optical Coherence Tomography ◽  
Frequency Response ◽  
Analytical Model ◽  
Spectral Resolution ◽  
Electrical Circuit ◽  
Optical Coherence ◽  
Digital Converter ◽  
Analog To Digital ◽  
Depth Sensitivity

We present an improved analytical model of a spectrometer for optical coherence tomography (OCT), which more accurately describes the OCT in-depth sensitivity fall-off. The model considers the intrinsic spectral resolution of the dispersive element and the influence of additional components (inequidistance-correcting prism). The model is validated by experimental data obtained both from other studies and our own experiments. The influence of the frequency response of the CCD electrical circuit and the analog-to-digital converter to the OCT signal fall-off was also detected and was shown to be significant in some cases.

scholarly journals Characterization of an analog-to-digital converter frequency response by a Josephson arbitrary waveform synthesizer

2019 ◽  
Vol 30 (3) ◽  
pp. 035006 ◽  
Author(s):  
Javier Díaz de Aguilar ◽  
J R Salinas ◽  
Oliver Kieler ◽  
Raúl Caballero ◽  
Ralf Behr ◽  
...  
Keyword(s):  
Frequency Response ◽  
Analog To Digital Converter ◽  
Digital Converter ◽  
Analog To Digital ◽  
Arbitrary Waveform

scholarly journals Depth-resolved analytical model and correction algorithm for photothermal optical coherence tomography

2016 ◽  
Vol 7 (7) ◽  
pp. 2607 ◽  
Author(s):  
Maryse Lapierre-Landry ◽  
Jason M. Tucker-Schwartz ◽  
Melissa C. Skala
Keyword(s):  
Optical Coherence Tomography ◽  
Analytical Model ◽  
Optical Coherence ◽  
Correction Algorithm

scholarly journals En face slab optical coherence tomography imaging successfully monitors progressive degenerative changes in the innermost layer of the diabetic retina

2020 ◽  
Vol 8 (1) ◽  
pp. e001120 ◽  
Author(s):  
Atsuko Katsuyama ◽  
Sentaro Kusuhara ◽  
Shun-Ichiro Asahara ◽  
Shun-Ichiro Nakai ◽  
Sotaro Mori ◽  
...  
Keyword(s):  
Experimental Data ◽  
Optical Coherence Tomography ◽  
Significant Negative Correlation ◽  
Blue Color ◽  
Optical Coherence ◽  
Red Color ◽  
En Face ◽  
Retinal Neurodegeneration ◽  
Oct Imaging ◽  
Diabetic Retinal Neurodegeneration

ObjectiveTo evaluate the usefulness of en face slab optical coherence tomography (OCT) imaging for monitoring diabetic retinal neurodegeneration with supporting animal experimental data.Research design and methodsWe retrospectively examined 72 diabetic eyes over 3 years using Cirrus-HD OCT. Two-dimensional en face slab OCT images of the innermost retina were reconstructed and graded according to the ratio of dark area to total area, and relative red, green, and blue color area ratios were calculated and used as indexes for each en face slab OCT image. Values from en face OCT images were used for statistical analyses. To obtain insight into the pathogenesis of diabetic retinal neurodegeneration, we used the InsPr-Cre;Pdk1flox/flox diabetic mouse model.ResultsBoth OCT grade and relative red color area ratio significantly increased with the advancing stage of diabetic retinopathy (p=0.018 and 0.006, respectively). After a mean follow-up period of 4.6 years, the trend was unchanged in the analyses of 42 untreated eyes (p<0.001 and 0.001, respectively). Visual acuity showed a weak but significant negative correlation with the red color ratio on en face slab OCT images, but central retinal thickness did not exhibit a clinically meaningful correlation with values obtained from en face slab OCT images. Immunohistochemical analyses of InsPr-Cre;Pdk1flox/flox diabetic mice demonstrated the loss of ganglion axon bundles and thinning of laminin without apparent retinal vascular change at the age of 20 weeks.ConclusionsEn face slab OCT imaging would be a novel useful modality for the assessment of diabetic retinal neurodegeneration as it could detect subtle optical changes occurring in the innermost retina in diabetic eyes. Our animal experimental data suggest that dark areas observed on en face slab OCT images might be the impairment of the extracellular matrix as well as neurons.

scholarly journals Dual-Channel Spectral Domain Optical Coherence Tomography Based on a Single Spectrometer Using Compressive Sensing

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 4006 ◽  
Author(s):  
Luying Yi ◽  
Liqun Sun ◽  
Mingli Zou ◽  
Bo Hou
Keyword(s):  
Optical Coherence Tomography ◽  
Compressive Sensing ◽  
Spectral Resolution ◽  
Single Channel ◽  
Optical Coherence ◽  
Channel System ◽  
Dual Channel ◽  
Imaging Depth ◽  
Imaging Speed ◽  
Sd Oct

Dual-channel spectral domain optical coherence tomography (SD-OCT) is one of the effective methods for improving imaging depth and imaging speed. In this paper, we design a dual-channel SD-OCT system based on a single spectrometer that can operate in two modes: (1) Increasing imaging speed and (2) expanding imaging depth. An optical path offset is preintroduced between the two channels to separate the two-channel data. However, this offset increases the requirement for the spectral resolution of the spectrometer in mode (1), so compressive sensing (CS) technology is used herein to overcome this problem. Consequently, in mode (1), when the spectral resolution of the spectrometer is the same as that used in the single-channel system, we use a dual-channel SD-OCT system combined with CS technology to double the imaging speed. In mode (2), when the spectral resolution of the spectrometer is only half of that used in a single-channel system, the imaging depth can be nearly doubled. We demonstrate the feasibility and effectiveness of the method proposed in this work by imaging a mirror, a fish fin, a fish eye, and an onion.

A semi-analytical model accounting for multiple scattering in optical coherence tomography

2005 ◽  
Author(s):  
Boris Karamata ◽  
Patrick Lambelet ◽  
Marcel Leutenegger ◽  
Markus Laubscher ◽  
Stephane Bourquin ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Multiple Scattering ◽  
Analytical Model ◽  
Optical Coherence

FACILITY FOR CALIBRATION OF PHOTOMETERS FOR TEMPORAL LIGHT MODULATION

2021 ◽  
Author(s):  
P.R. Dekker ◽  
A.L. van Bloois
Keyword(s):  
Frequency Response ◽  
Root Mean Square ◽  
Contrast Ratio ◽  
Standard Uncertainty ◽  
Reference Source ◽  
Mean Square ◽  
Light Modulation ◽  
Digital Converter ◽  
Analog To Digital ◽  
Acousto Optic Modulator

We developed a facility for calibration of TLM (temporal light modulation) photometers. The facility is based on a laser-fed reference source, of which the radiance can be modulated with an acousto-optic modulator (AOM). A system of photodiodes, amplifiers, and an analog-to-digital converter (ADC) is used to sample the temporally modulated radiance of the source. With the facility a TLM photometer was calibrated for display contrast ratio RMS (root mean square) with an absolute combined standard uncertainty of 0,037 %. In addition, the facility has been characterised with the aim of measuring flicker and stroboscopic effect, considering the Ecodesign ‘Single Lighting Regulation’. The frequency response of the facility shows to be sufficient to accommodate measurements of flicker and the stroboscopic effect.

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