American Journal of Optics and Photonics最新文献

Three Prenatal Developments in the Retina Allow for Cortico-Retinal Image Processing in Situ in the Eye 视网膜的三种产前发育可在眼内就地进行皮质-视网膜图像处理

American Journal of Optics and Photonics Pub Date : 2024-03-20 DOI: 10.11648/j.ajop.20241201.11

Norbert Lauinger

{"title":"Three Prenatal Developments in the Retina Allow for Cortico-Retinal Image Processing in Situ in the Eye","authors":"Norbert Lauinger","doi":"10.11648/j.ajop.20241201.11","DOIUrl":"https://doi.org/10.11648/j.ajop.20241201.11","url":null,"abstract":"Image processing in the retina of the eye has thus far been mainly dealt with analogous to photographic ray optics i. e., imaging lens optics and photodiode arrays. However, it does not offer an answer to the questions that are crucial to human vision: WHAT a visible object invariantly represents conceptually (a house, a tree, etc.), WHERE it is located in relation to other objects in space or which RGB-colors and/or luminosities collaborate locally. For this purpose, ray optics needs to be supplemented by diffractive wave optics, which can be described as Fresnel near-field interference in cellular or spatial gratings. The fact that interference optics plays a decisive role in vision has already been proven by the fact that in binocular vision the image brightness is preserved when closing one eye. However, with the introduction of interference-wave-optics and especially with Fresnel Nearfield interference optics the cortico-retinal image processing now becomes possible in the eye, i.e. in the retina of the peripheral visual organ. Fresnel Nearfield interference optics especially allows multilayer proceeding and a better understanding of hierarchical imaging systems. It clearly becomes apparent in the di- and trichromatic proceeding and by the separation of color proceeding from invariant object form proceeding. Color - as an example - is not produced at the visual objects and also not in the cortex, but in the Fresnel space of the retina.\u0000","PeriodicalId":246919,"journal":{"name":"American Journal of Optics and Photonics","volume":"10 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140225545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cooling and Trapping of Fröhlich Polaron and Observation of Plasma Formation in Magnetic Field 弗洛里希极子的冷却与捕获以及磁场中等离子体的形成观测

American Journal of Optics and Photonics Pub Date : 2023-11-11 DOI: 10.11648/j.ajop.20231101.12

Njutapmvoui Adamou, Mwebi Ekengoue Clautaire, Kenfack Jiotsa Aurelien, Kenfack Sadem Christian, Fotue Alain Jervé, Lukong Cornelius Fai

引用次数: 0

A Method of Infrared Image Pedestrian Detection with Improved YOLOv3 Algorithm 一种改进YOLOv3算法的红外图像行人检测方法

American Journal of Optics and Photonics Pub Date : 2021-08-26 DOI: 10.11648/J.AJOP.20210903.11

Yue Sun, Yifeng Shao, Guanglin Yang, H. Xie

{"title":"A Method of Infrared Image Pedestrian Detection with Improved YOLOv3 Algorithm","authors":"Yue Sun, Yifeng Shao, Guanglin Yang, H. Xie","doi":"10.11648/J.AJOP.20210903.11","DOIUrl":"https://doi.org/10.11648/J.AJOP.20210903.11","url":null,"abstract":"The principle of infrared image is thermal imaging technology. Infrared pedestrian detection technology can be applied to the safety monitoring of the elderly, which can not only protect personal privacy, but also realize pedestrian identification at night, which has strong application value and social significance. A method of infrared image pedestrian detection with improved YOLOv3 algorithm is proposed to increase the detection accuracy and solve the problem of low detection accuracy caused by infrared pedestrian target edge blurring. And according to the characteristics of infrared pedestrian, a complex sample data set is established which is applied to infrared pedestrian detection. The infrared image enhancement method with WDSR-B is adopted to improve the clarity of the data set. In addition, based on YOLOv3 algorithm, the output of the 4-time down-sampling layer is added to obtain richer context information for small targets and improve the detection performance of the network for small-target pedestrians. And the improved YOLOv3 network is trained by the enhanced infrared data set. Experimental results show that the scheme precision of pedestrian detection is higher than that of YOLOv3 algorithm. Therefore, this method can be applied to the detection of pedestrians at night and the safety monitoring of the elderly.","PeriodicalId":246919,"journal":{"name":"American Journal of Optics and Photonics","volume":"90 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130416235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulation of the Effect of Relative Refractive Index for Light Transmission Through Double Cladding Step Index Optical Fibre 相对折射率对双包层阶梯折射率光纤光传输影响的模拟

American Journal of Optics and Photonics Pub Date : 2021-07-15 DOI: 10.11648/J.AJOP.20210902.11

K. A. Busari, O. O. Galadima, Suleiman Lawan Garba, Taiwo Abduljelil Busari, Muhammed Yusuf Gambo, Musbaudeen Alaba Afolabi, Hassan Adamu

{"title":"Simulation of the Effect of Relative Refractive Index for Light Transmission Through Double Cladding Step Index Optical Fibre","authors":"K. A. Busari, O. O. Galadima, Suleiman Lawan Garba, Taiwo Abduljelil Busari, Muhammed Yusuf Gambo, Musbaudeen Alaba Afolabi, Hassan Adamu","doi":"10.11648/J.AJOP.20210902.11","DOIUrl":"https://doi.org/10.11648/J.AJOP.20210902.11","url":null,"abstract":"This work establishes computational analysis of relative refractive index property for light transmission via fiber optics using MATLAB simulation. Optical fiber is a dielectric wave guide which transmits signal with a low attenuation and dispersion at higher bandwidth or data rate. Recent advances in fiber optics introduced a largely new dimension into optical technology with the effect of improving transmission through the application of cladding system. Cladding in fiber communication is importantly applied to ease light transmission in the fiber-core interface by total internal reflection at the boundary between two light propagation region of a typical fiber. Optical fiber communication is a well recognized aspect of optical light transmission where clad fibers of different refractive indices recount for a measurable Numerical aperture and Acceptance angle in fiber networking and communication technology. This has lead to the efficient and effective optical transmission due to the adequate emergence and utilization of optical properties and parameters in optical fiber applications. A double cladding was set for the fiber and a maximum relative refractive index of 2.000% is obtained for an acceptance angle and numerical aperture range of 59°-64° and 0.859-0.900 respectively. This implies fast light transmission, high bandwidth and small bending sensitivity for fiber networking with applications in medicine and telecommunication compared to single cladding fiber.","PeriodicalId":246919,"journal":{"name":"American Journal of Optics and Photonics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130696791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Seed-mediated Growth of Silver Nanoplates and Investigation on Their Nonlinear Optical Behaviors 银纳米片的种子介导生长及其非线性光学行为研究

American Journal of Optics and Photonics Pub Date : 2021-03-26 DOI: 10.11648/J.AJOP.20210901.13

Yalan Wang, Xiang Li, Anle Wang, Jin Zhang, Jianghai Wo, Ququan Wang

{"title":"Seed-mediated Growth of Silver Nanoplates and Investigation on Their Nonlinear Optical Behaviors","authors":"Yalan Wang, Xiang Li, Anle Wang, Jin Zhang, Jianghai Wo, Ququan Wang","doi":"10.11648/J.AJOP.20210901.13","DOIUrl":"https://doi.org/10.11648/J.AJOP.20210901.13","url":null,"abstract":"Silver nanoplates have obvious advantages compared with other silver structural nanoparticles due to their wide tunability of the local surface plasmon resonance (LSPR) and significant local field enhancement around the sharp corners. Nonlinear optical absorption (NLA) and nonlinear optical refraction (NLR) are widely employed to characterize the nonlinear optical properties due to their simply testing requirement and comparable valuable results. Z-scan method is widely used in optical characterization of nonlinear properties of different materials. Here, a seed-mediated growth method of the silver nanoplates with well controlled size and local surface plasmon wavelength is presented. The nanoparticle size increases gradually and becomes more uniform distribution as the red-shift of the plasmon resonance wavelength from 650 nm to 950 nm. In particular, we show the dependence of NLA and NLR of the silver nanoplates on the LSPR. The absolute value of effective NLA coefficient increases from 1.38 to 4 cm/GW and that of the NLR index increases as large as 3 times when the LSPR wavelength changes from 728 nm to 898 nm, which is attributed to the strong plasmon absorption and local filed enhancement of larger size silver nanoplates. These findings have great potentials in the explorations of functional non-linear devices.","PeriodicalId":246919,"journal":{"name":"American Journal of Optics and Photonics","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128448217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

V-type Three-Level Laser Coupled to Squeezed Vacuum Reservoir v型三能级激光耦合压缩真空储层

American Journal of Optics and Photonics Pub Date : 2021-03-03 DOI: 10.11648/J.AJOP.20210901.11

Gomera Biyazn, Misrak Gatahun

{"title":"V-type Three-Level Laser Coupled to Squeezed Vacuum Reservoir","authors":"Gomera Biyazn, Misrak Gatahun","doi":"10.11648/J.AJOP.20210901.11","DOIUrl":"https://doi.org/10.11648/J.AJOP.20210901.11","url":null,"abstract":"The squeezing, entanglement, and statistical properties of cavity modes produced by V-type three-level laser coupled to squeezed vacuum reservoir were studied employing the steady state solutions of the expectation values of the cavity mode operators. The study showed that a light in squeezing state can be produced by the system under consideration under the condition that the cavity decay constant is larger than linear gain coefficient and the squeezing occurs in the plus-quadrature. The cavity modes do not exhibit entanglement properties. It is also observed that the degree of squeezing increases with the linear gain coefficient and squeezing parameter. We also determined the mean and variance of the photon number, intensity difference fluctuations, and the second order correlation function of the two modes. The mean and variance of the photon number as well as the correlation function of two modes decrease as the difference of the probability of the two states at initial time increases. The photons have super-poissionian statistics. The point, η, at which the maximum intensity difference fluctuation occurred depends on linear gain coefficient but not squeezing parameter. The result shows that the correlation of the two modes decreases as η the linear gain coefficient and squeezing parameter.","PeriodicalId":246919,"journal":{"name":"American Journal of Optics and Photonics","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131977562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Space Object Detection Algorithm Leveraging Absolute Photo-Detector Calibration 利用绝对光电探测器校准的空间目标检测算法

American Journal of Optics and Photonics Pub Date : 2021-03-03 DOI: 10.11648/J.AJOP.20210901.12

S. Cain

{"title":"Space Object Detection Algorithm Leveraging Absolute Photo-Detector Calibration","authors":"S. Cain","doi":"10.11648/J.AJOP.20210901.12","DOIUrl":"https://doi.org/10.11648/J.AJOP.20210901.12","url":null,"abstract":"This paper introduces a new space object detection algorithm that is designed to process image data taken from astronomical telescopes for the purposes of finding sources of optical radiation in space. Specifically, the algorithm is designed to find unresolvable space objects or objects that possess an angular size that is too small to appear as anything, but a point source as viewed through the telescope conducting the search. The proposed approach involves calibrating the image data into units of photoelectrons and then executing an estimation algorithm to compute the strength of the hypothetical sources in the image. A Likelihood Ratio Test (LRT) is then implemented to make a determination if the hypothetical sources are classified as space objects or not. The proposed algorithm is demonstrated to achieve a higher probability of detecting unresolvable objects than the matched filter, which is still the state-of-the-art approach for finding optical sources in astronomical images. The new approach involves a pre-processing step where the amplitude of the optical source in a given test location is estimated under the hypothesis that at optical source exists at that location. The median filter is used to estimate the background level in the vicinity of the test location. Once these parameters are estimated, A likelihood ratio test is used to determine whether an object is present at the test location. The new algorithm is tested against the matched filter detector using two sets of measured short exposure data of the star Polaris and two stars in its vicinity taken with a small telescope. Receiver Operating Characteristic (ROC) curves are produced for the two detection schemes showing that the new algorithm out-performs the old one with a difference of 10 percent in the probability of detection, which is demonstrated to be statistically significant in these experiments with confidence as high as 90%.","PeriodicalId":246919,"journal":{"name":"American Journal of Optics and Photonics","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126749728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Image Registration Method Based on Optimized SURF Algorithm 基于优化SURF算法的图像配准方法

American Journal of Optics and Photonics Pub Date : 2019-12-18 DOI: 10.11648/J.AJOP.20190704.11

Zhang Sheng, Liu Peihua, Liu Yuli, Qi Mingsi, Ji Changgang, Zhou Meng

引用次数: 4

Comparative Study Between Erythrocytes Blood Cells and Modulated Circular Aperture Using Speckle Photography 用散斑摄影对红细胞、血细胞和调制圆孔径的比较研究

American Journal of Optics and Photonics Pub Date : 2019-10-09 DOI: 10.11648/J.AJOP.20190703.12

A. Hamed, T. A. Al-Saeed

{"title":"Comparative Study Between Erythrocytes Blood Cells and Modulated Circular Aperture Using Speckle Photography","authors":"A. Hamed, T. A. Al-Saeed","doi":"10.11648/J.AJOP.20190703.12","DOIUrl":"https://doi.org/10.11648/J.AJOP.20190703.12","url":null,"abstract":"A manipulation of four circles arranged along the Cartesian coordinates in uniform circular aperture is compared with selected four blood cells forming the object using the technique of speckle photography. The aperture model is considered have two- fold symmetry. A diffuser is placed in the same plane of the object or the model of four circles in order to get the modulated speckle pattern which is the Fourier spectrum of object information convoluted with the Fourier spectrum of the random diffuser. The modulated speckle pattern is smeared by the Point Spread Function computed from the diffraction corresponding to the whole circular aperture. The reconstruction process gave nearly similar speckle images little degraded by the noise originated from the diffuser. The Point Spread Function corresponding to the model of four circles is computed analytically and also using the FFT technique. A comparison is made with the Fourier spectrum of the blood cells and its corresponding autocorrelation function giving nearly similar results. We can acquire the erythrocytes blood cells in the imaging plane by operating the FFT upon the modulated speckle images. The reconstructed images of blood cells are affected by the noise originated from the diffuser. A Mat- Lab code is made in the construction of the aperture and all the images computed in the processing.","PeriodicalId":246919,"journal":{"name":"American Journal of Optics and Photonics","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130951946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

20 G bps Pulse Amplitude Modulation (PAM) Format for Capacity Upgrade in Optical Communications 用于光通信容量升级的20g bps脉冲幅度调制(PAM)格式

American Journal of Optics and Photonics Pub Date : 2019-09-10 DOI: 10.11648/j.ajop.20190702.13

Yegon Geoffrey Kipkoech, Waswa David Wafula, Isoe George Mosoti, Arusei Geoffrey Kipkorir, Rtich Kipkoske Samwel, Timothy Braidwood, L. Andrew

{"title":"20 G bps Pulse Amplitude Modulation (PAM) Format for Capacity Upgrade in Optical Communications","authors":"Yegon Geoffrey Kipkoech, Waswa David Wafula, Isoe George Mosoti, Arusei Geoffrey Kipkorir, Rtich Kipkoske Samwel, Timothy Braidwood, L. Andrew","doi":"10.11648/j.ajop.20190702.13","DOIUrl":"https://doi.org/10.11648/j.ajop.20190702.13","url":null,"abstract":"In the fast growing society, communication is broadening so rapidly such that internet users need to access information rapidly and amount of data flowing through internet is very huge. Various techniques for increasing capacity in data centers have drawn lots of attention in recent years. One way of addressing this demand is introduction of advanced optical modulation formats which has been motivated by the demand for high transmission capacity and better system reliability. In this work, two electrical data streams at bit rate of 10 G bps each were combined to produce 20 G bps multilevel system 4-PAM with four levels. One of the four amplitudes represents a combination of two bits (00, 01, 10, 11) per symbol. This therefore transmits two bits in parallel and therefore the data rate is doubled. The generated data was transmitted over 3.21km G.652 fiber at standard BER of 10-9. This format can be used to simultaneously transmit two bits per symbol per wavelength thereby increasing the overall link transmission speed while maintaining the channel bandwidth. We further demonstrated a digital signal processing assisted receiver to efficiently recover the transmitted signal without employing costly receiver hardware. The ability to use a single photodiode to demodulate the multilevel signal, brings a further reduction in cost on implementing the scheme. This spectral efficient modulation format will achieve even higher data rate per channel when coupled in a Dense Wavelength Division Multiplexing (DWDM) system. This will therefore lead to significant cost saving of capital investment and easing the system management and hence an efficient utilization of bandwidth.","PeriodicalId":246919,"journal":{"name":"American Journal of Optics and Photonics","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123680227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0