Article
Optics
Xiupin Wu, Wanrong Gao, Haiyi Bian
Summary: This study presents a self-denoising method for OCT images using single spectrogram-based deep learning. It can customize different noises in different images with low computation. Experimental results show that the method effectively reduces speckle patterns and stripes, improving the signal-to-noise ratio and image contrast.
Article
Optics
Yusi Miao, Jun Song, Myeong Jin Ju
Summary: A fast and practical computational cross-calibration method for multiple spectrometers is described, which constructs a signal correlation matrix and can be used for physical alignment or numerical matching of spectra. The performance is comparable to the previously reported optimization approach.
Article
Optics
Dong Yang, Zhongming Yang, Yanfeng Zhang
Summary: This paper proposes and demonstrates a nano-displacement measurement system based on WSI-OAM, which features compact size and easy alignment. It achieves high accuracy and linearity with a resolution of 0.1 nm and an uncertainty of 0.013 nm for measuring nanoscale displacements.
Article
Optics
Qingrui Li, Tianduo Lai, Zhenyang Ding, Kuiyuan Tao, Fengyu Zhu, Hao Kuang, Peidong Hua, Yin Yu, Tiegen Liu
Summary: This paper compares polarization imaging methods based on Jones matrix and Mueller matrix, finding that Mueller matrix performs better in handling non-coaxial diattenuation. Experimental results show that Mueller matrix with incoherent averaging method has better performance in areas with low signal to noise ratio.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Optics
Zhenhe Ma, Ning Ding, Zhen Li, Keliang Zhu, Ang Li, Zhanhong Lin, Yi Wang, Yuqian Zhao, Yao Yu, Jingmin Luan, Xin Zhu, Jian Liu
Summary: This article introduces a method to extract the photoacoustic (PA) signal from the contrast reduction in the interference spectrum obtained from spectral domain optical coherence tomography (SDOCT). The method utilizes the specular reflection on the water surface to achieve all-optical detection in a non-contact manner. By analyzing the phase changes in the interference spectrum induced by water surface vibration, the method enables quantification of the interference contrast reduction for PA imaging.
Article
Optics
Yue Zhang, Wanrong Gao, Chenxia Xie
Summary: This paper proposes a new method to remove noise in blood flow images using the spatial frequency information of motion noise. The effectiveness of the adaptive denoising algorithm is verified through finger blood flow imaging. It is found that applying the algorithm improves the signal-to-noise ratio and contrast-to-noise ratio of OCTA images.
Article
Engineering, Electrical & Electronic
Jonathan M. Wheeler, Jacob N. Chamoun, Michel J. F. Digonnet
Summary: Phase noise can be modulated onto laser output using an electro-optic phase modulator to create an incoherent source with low intensity noise. Adjusting amplifier parameters can vary carrier suppression, with simulations showing suppressions better than -30 dB attainable. These parameter selections help mitigate effects of voltage fluctuations due to temperature changes and component aging.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Optics
Xiangsen Guo, Guangyuan Ren, Jianbo Tang
Summary: In this study, an autocorrelation analysis-based optical coherence tomography (OCT) method was introduced for accurate measurement of blood flow velocity in the capillary network. The axial blood flow velocity was obtained from the phase change in the decorrelation period of the first-order field autocorrelation function (g1) of the OCT field data. The proposed method showed accurate measurement of axial speed in the range of 0.5-15 mm/s in phantom experiments, and it achieved robust axial velocity measurements with more than five times shorter acquisition time compared to phase-resolved Doppler optical coherence tomography (pr-DOCT) in living animals.
Article
Computer Science, Hardware & Architecture
Mamta Juneja, Gurunameh Singh Chhatwal, Shatabarto Bhattacharya, Niharika Thakur, Prashant Jindal
Summary: Optical Coherence Tomography (OCT) is an advanced imaging technique used for diagnosing retinal abnormalities by capturing the retinal layers using low coherence light waves. However, the presence of speckle noise hinders accurate diagnosis. This paper proposes an approach using an Autoencoder-based Dense Denoiser (ADD) neural network and Block-based Wiener Filter (BBWF) to eliminate speckle noise without compromising important image details.
COMPUTERS & ELECTRICAL ENGINEERING
(2023)
Article
Cardiac & Cardiovascular Systems
Laurens J. C. van Zandvoort, Kenichiro Otsuka, Martin Villiger, Tara Neleman, Jouke Dijkstra, Felix Zijlstra, Nicolas M. van Mieghem, Brett E. Bouma, Joost Daemen
Summary: In this study, PS-OFDI was used to quantitatively assess the polarization properties of coronary thrombus in ACS patients, revealing significantly higher birefringence in organizing thrombus compared to fresh thrombus. Additionally, ischemic time was identified as a significant predictor for birefringence in thrombus regions from culprit lesions.
CIRCULATION JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Shizi Yu, Meisong Liao, Liang Chen, Tianxing Wang, Wanjun Bi, Weiqing Gao, Weibiao Chen, Lili Hu
Summary: We proposed a method for generating flat supercontinuum in a specified band using non-degenerate Raman four-wave mixing modulation. By controlling the dispersion of the photonic crystal fiber and the peak power of the pump light, we achieved broadband hyperspectral intensities in the short-wavelength direction. This method offers a new light source for optical coherence tomography, with improved axial resolution.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Optics
Xiaojun Yu, Chenkun Ge, Mingshuai Li, Jinna Chen, Perry Ping Shum
Summary: In this study, the influences of statistical noise distributions on OCT despeckling were evaluated, and a noise distribution analysis-based despeckling method was proposed. By establishing a noise model and using a two-step filtering mechanism, the proposed method is capable of effectively suppressing both multiplicative and additive noises while retaining important image structural details.
LASER PHYSICS LETTERS
(2022)
Article
Optics
Shengjian Huang, Chen Tang, Min Xu, Zhenkun Lei
Summary: Removing speckles with structural protection in OCT images is achieved through the proposed cluster-based filtering framework in this research, which consists of preprocessing, structure extraction, and structure denoising stages to protect the structural texture while eliminating noise.
APPLIED PHYSICS B-LASERS AND OPTICS
(2021)
Article
Optics
Jianan Fang, Kun Huang, E. Wu, Ming Yan, Heping Zeng
Summary: This article introduces an infrared 3D imaging system capable of detecting three-dimensional structure and reflectivity information. The system operates at single-photon sensitivity and femtosecond timing resolution, enabling imaging under low-light conditions. By nonlinear frequency upconversion and recording with a silicon camera, the presented system achieves high lateral and depth resolutions for 3D reconstruction. Additionally, a numerical denoiser based on spatiotemporal correlation allows the retrieval of object profile and reflectivity even with a detected flux below 0.05 photons/pixel/second. This infrared 3D imager features high detection sensitivity, precise timing resolution, and wide-field operation, offering new possibilities in life and material sciences.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Optics
Huaiguang Chen
Summary: Optical coherence tomography (OCT) is a key tool in biological research and clinical applications, but speckle noise can degrade image quality and hinder subsequent analysis. A novel fusion algorithm based on point-estimated and block-estimated methods is proposed to remove speckle noise, outperforming existing denoising methods according to experimental results.
