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Symmetry in optics and photonics:a group theory approach

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Science Bulletin 2018年第4期63卷 244-251页

作者： B.M.Rodriguez-Lara Ramy EI-Ganainy Julio Guerrero Tecnologico de Monterrey.Escuela de Ingenieria y Ciencias Monterrey 64849Mexico instituto nacional de astrofisica Optica y Electr6nicaPueblaCP 72840Mexico department of Physics and Hexes Center for Quantum Phenomena Michigan Technological UniversityHoughton.MI 49931USA departamento de Matematicas Facultad de Ciendas Experimentales y de la SaludCampus Las LagunillasUniversidad de Jaen23071JaenSpain departamento de Ingenierfa y Tecnologia de Computadores Facultad de lnformdticaCampus EspinardoUnivesidad de Murcia30100 MurciaSpain

Group theory(GT) provides a rigorous framework for studying symmetries in various disciplines in physics ranging from quantum field theories and the standard model to fluid mechanics and chaos theory. To date, the application of such a powerful tool in optical physics remains limited. Over the past few years however, several quantum-inspired symmetry principles(such as parity-time invariance and supersymmetry) have been introduced in optics and photonics for the first time. despite the intense activities in these new research directions, only few works utilized the power of group theory. Motivated by this status quo, here we present a brief overview of the application of GT in optics, deliberately choosing examples that illustrate the power of this tool in both continuous and discrete setups. We hope that this review will stimulate further research that exploits the full potential of GT for investigating various symmetry paradigms in optics, eventually leading to new photonic devices.

关键词： Group theoryHelmholtz equationDiscrete opticsParity-time (PT) symmetry

Holograms in Albumins and Optical Properties Recorded in Real Time

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Optics and Photonics Journal 2015年第5期5卷 177-192页

作者： Arturo Olivares-Pérez Manuel Jorge Ordónez-Padilla Santa Toxqui-López Optics department Instituto Nacional de Astrofisica Opticay ElectronicaPueblaMexico Facultad de Ingenieria Benemerita Universidad Autonoma de PueblaPueblaMexico

Holographic recording analysis was performed on the films that were sensitized with ammonium dichromate with albumin of hen and quail (Gallus gallus and Callipepla cali) as abiopolymeric photosensitive matrix. The samples were exposed to an He-Cd laser, λ = 442 nm, at various concentrations, and diffraction efficiencies were measured as a function to the energy, thickness, protein density, aging time, and spatial frequencies. The photosensitivity was measured as a function of storage time, and the gratings were recorded in real time. The photochemical processes involved in the formation of holographic image are described. The results indicate the behavior of colloidal systems based on albumin bird build holographic recording materials.

关键词： Biopolymer Proteins Holograms Albumins Diffraction Gratings Diffraction devices

Transfer of Machined Patterns on an Aluminum Plate to Pyrex Glass Using Reactive Ion Etching SF_(6) Plasma without Masks

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Journal of Surface Engineered Materials and Advanced Technology 2014年第5期4卷 262-269页

作者： Carlos M.Ortiz-Lima Fernando J.Quinones-Novelo Alberto Jaramillo-Nunez Jorge Castro-Ramos Insitituto nacional de astrofisica Optica y ElectronicaPueblaMexico

A method for etching the surface of a Pyrex glass substrate using the Reactive Ion Etching process without the use of masks is reported. Variations in the machined surface on an auxiliary plate, manufactured in aluminum and placed below a Pyrex glass slide, were transferred to the upper surface of the substrate. SF6 as etching gas and low pressure chamber to promote the increase of mean free path of ions were used. Two etching ratios were found, general, that affects the entire surface of the substrate, and differential, which generates the relief on the surface of the glass. Differential etching depth showed a linear behavior with respect to time;the mean differential etching rate obtained was 43 nm/min. The same phase between the auxiliary plate machining and the etched pattern on the substrate is preserved. With this technique it was possible to manufacture convex and concave surfaces;some examples are given. The arithmetic mean roughness achieved with the proposed method was found to be N1 class, ideal for the development of optical corrector plates.

关键词： Reactive Ion Etching No Masking RIE SF_(6) Plasma Etching

Laser Wavelength Estimation Method Based on a High-Birefringence Fiber Loop Mirror

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Photonic Sensors 2019年第1期9卷 89-96页

作者： Ricardo I.ALVAREZ-TAMAYO Patricia PRIETO-CORTES Manuel DURAN-SANCHEZ Baldemar IBARRA-ESCAMILLA Antonio BARCELATA-PINZON Evgeny A.KUZIN Faculty of Physical-Mathematical Sciences CONACYT-Universidad Autonoma de Nuevo LeonSan Nicolas de los Garza 66451Mexico Faculty of Physical-Mathematical Sciences Universidad Autonoma de Nuevo LednSan Nicolas de los Garza 66451 Mexico Optics department CONA CYT-Instituto Nacional de AstrofisieaOptica y EleetronieaTonantzintla 72480Mexico Optics department Instituto Nacional de AstrofisicaOptica y ElectronicaTonantzintla 72480Mexico Mechatronics division Universidad Tecnologica de PueblaPuebla 72300Mexico

A simple method for the estimation of the wavelength of a fiber laser system is proposed. The method is based on the use of a high-birefringence-fiber loop mirror(HBFLM).The HBFLM exhibits a periodic transmission/reflection spectrum whose spectral characteristics are determined by the length and temperature of the high-birefringence fiber(HBF).Then,by the previous characterization of the HBFLM spectral transmission response,the central wavelength of the generated laser line can be *** using a photodetector,the *** of the laser line is estimated during an HBF temperature scanning by measuring the temperature at which the maximum transmitted power of the HBFLM is *** proposed method is demonstrated in a linear cavity tunable Er/Yb fiber *** method is a reliable and low-cost alternative for laser wavelength determination in short wavelength ranges without the use of specialized and expensive equipment.

关键词： Wavelength meter fiber lasers fiber optical loop mirror high-birefringence fiber

Compound Hidden Markov Model for Activity Labelling

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International Journal of Intelligence Science 2015年第5期5卷 177-195页

作者： Jose Israel Figueroa-Angulo Jesus Savage Ernesto Bribiesca Boris Escalante Luis Enrique Sucar Biorobotics Laboratory Universidad Nacional Autonoma de Mexico Mexico City Mexico Computer Science department Universidad Nacional Autonoma de Mexico Mexico City Mexico Electrical Engineer department Universidad Nacional Autonoma de Mexico Mexico City Mexico Computer Science department Instituto Nacional de Astrofisica Optica y Electronica Puebla Mexico

This research presents a novel way of labelling human activities from the skeleton output computed from RGB-D data from vision-based motion capture systems. The activities are labelled by means of a Compound Hidden Markov Model. The linkage of several Linear Hidden Markov Models to common states, makes a Compound Hidden Markov Model. Each separate Linear Hidden Markov Model has motion information of a human activity. The sequence of most likely states, from a sequence of observations, indicates which activities are performed by a person in an interval of time. The purpose of this research is to provide a service robot with the capability of human activity awareness, which can be used for action planning with implicit and indirect Human-Robot Interaction. The proposed Compound Hidden Markov Model, made of Linear Hidden Markov Models per activity, labels activities from unknown subjects with an average accuracy of 59.37%, which is higher than the average labelling accuracy for activities of unknown subjects of an Ergodic Hidden Markov Model (6.25%), and a Compound Hidden Markov Model with activities modelled by a single state (18.75%).

关键词： Hidden Markov Model Compound Hidden Markov Model Activity Recognition Human Activity Human Motion Motion Capture Skeleton Computer Vision Machine Learning Motion Analysis

A close-in substellar object orbiting the sd OB-type eclipsing-binary system NSVS 14256825

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Research in Astronomy and Astrophysics 2019年第9期19卷 129-136页

作者： Li-Ying Zhu Sheng-Bang Qian Eduardo Fernaez Lajus Zhi-Hua Wang Lin-Jia Li Yunnan Observatories Chinese Academy of SciencesKunming650216China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming650216China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing100101China University of Chinese Academy of Sciences Beijing100049China Facultad de Ciencias Astronomicas y Geofisicas Universidad Nacional de La Plata1900La PlataBuenos AiresArgentina instituto de astrofisica de La Plata(CCT La Plata C CONICET/UNLP) Paseo del Bosque s/nLa PlataBAB1900FWAArgentina

NSVS 14256825 is the second discovered sdOB+dM eclipsing-binary system with an orbital period of 2.65 h. This special binary was reported to contain circumbinary planets or brown dwarfs by using the timing method. However, different results were derived by different authors because of the insufficient coverage of eclipse timings. Since 2008, we have monitored this binary for about 10 yr using several telescopes and 84 new times of light minimum were obtained with high precision. It is found that the O-C curve has been increasing recently and it shows a cyclic variation with a period of 8.83 yr and an amplitude of 46.31 seconds. The cyclic change cannot be explained by magnetic activity cycles of the red dwarf component because the required energy is much larger than that radiated by this component in one whole period. This cyclic change detected in NSVS 14256825 could be explained by the light-travel time effect via the presence of a third body. The lowest mass of the third body is determined to be 14.15 Mjupwhich is in the transition range between planets and brown dwarfs. The substellar object is orbiting around this evolved binary at an orbital separation of around 3 AU with an eccentricity of 0.12. These results indicate that NSVS 14256825 is the first sdOB-type eclipsing binary consisting of a hierarchical substellar *** detection of a close-in substellar companion to NSVS 14256825 will provide some insights on the formation and evolution of sdOB-type binaries and their companions.

关键词： binaries:close binaries:eclipsing stars:evolution stars:individual(NSVS 14256825)

Topological protection of partially coherent light

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Photonics Research 2022年第5期10卷 1223-1231页

作者： KONRAD TSCHERNIG GABRIEL MARTINEZ-NICONOFF KURT BUSCH MIGUEL A.BANDRES ARMANDO PEREZ-LEIJA Max-Born-lnstitut 12489 BerlinGermany Humboldt-Universität zu Berlin Institut fur PhysikAG Theoretische Optik&Photonik12489 BerlinGermany Coordinacidn deÓptica Instituto Nacional de AstrofisicaÓpticay Electronica72840 TonantzintlaPueblaMexico CREOL The College of Optics and PhotonicsUniversity of Central FloridaOrlandoFlorida 32816USA

Topological physics exploits concepts from geometry and topology to implement systems capable of guiding waves in an unprecedented *** ideas have led to the development of photonic topological insulators,which are optical systems whose eigenspectral topology allows the creation of light states that propagate along the edge of the system without any coupling into the bulk or backscattering even in the presence of ***,topological protection is a fully coherent effect,and it is not clear to what extent topological effects endure when the wavefronts become partially ***,we study the interplay of topological protection and the degree of spatial coherence of classical light propagating in disordered photonic topological *** results reveal the existence of a well-defined spectral window in which partially coherent light is topologically *** opens up the design space to a wider selection of light sources,possibly yielding smaller,cheaper,and more robust devices based on the topological transport of light.

关键词： topological coherent topology

A triplet of the only pulsation mode detected in the DAV star G132–12

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Research in Astronomy and Astrophysics 2021年第6期21卷 276-280页

作者： Wen-Chao Su Jian-Ning Fu Jian-Xing Chen Lester Fox-Machado Shi-Jie Zhao Carmen Ayala-Loera Jiang-Tao Wang Yang Pan department of Astronomy Beijing Normal UniversityBeijing 100012China Dipartimento di Fisica e Astronomia Alma Mater Studiorum Universita’di Bolognavia Piero Gobetti 93/21-40129 BolognaItaly INAF-Osservatorio di astrofisica e Scienze dello Spazio di Bologna Via Piero Gobetti 93/31-40129 BolognaItaly instituto de Astronomia Universidad Nacional Autonoma de MexicoApartado Postal 87722800 EnsenadaBaja CaliforniaMexico Institute of Astronomy&Astrophysics Academia SinicaTaipeiChina

Hydrogen atmosphere pulsating white dwarfs,also known as DAV stars,are the most abundant type of pulsating white ***-temperature DAV stars in general exhibit a small number of pulsation modes and stable frequencies.G132-12 is one of the pulsating hydrogen atmosphere white dwarf stars which lies close to the blue edge of the instability *** researches reported that G132-12 might have only one pulsation mode with the period of 212.69 *** study the pulsation properties of G132-12 in detail,we carried out a bi-site observation campaign in October *** series photometric data were collected during around 154 h in total.A Fourier analysis reveals three frequencies which are identified as the triplet of an l=1 g-mode pulsation with the period of 212.499 *** rotational period is derived as Prot=35.0±6.7 h and the inclination of the rotational axis to the line of sight is 70°.G132-12 could be an ideal target for measuring the cooling scale of this white dwarf star with only one excited pulsation mode detected.

关键词： white dwarfs oscillations photometric

BVRI photometric observations,light curve solutions and orbital period analysis of BF Pav

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Research in Astronomy and Astrophysics 2021年第8期21卷 193-202页

作者： Atila Poro Fahri Alicavus Eduardo Fernández-Lajús Fatemeh Davoudi PegahSadat MirshafieKhozani Mark G.Blackford Edwin Budding Behjat Zarei Jalalabadi Jabar Rahimi Farzaneh Ahangarani Farahani The International Occultation Timing Association Middle East section Iran Astronomy department of the Raderon Lab BurnabyBCCanada Canakkale Onsekiz Mart University Faculty of Arts and SciencesDepartment of Physics17020CanakkaleTurkey Canakkale Onsekiz Mart University Astrophysics Research Center and Ulupnar Observatory17020CanakkaleTurkey instituto de astrofisica de La Plata(CCT La Plata-CONICET-UNLP) La PlataArgentina Facultad de Ciencias Astronomicas y Geofisicas Universidad Nacional de La PlataPaseo del BosqueB1900FWALa PlataArgentina Variable Stars South(VSS) Congarinni ObservatoryCongarinniNSW2447Australia Carter Observatory 40 Salamanca RdKelburnWellington 6012New Zealand

A new ephemeris,period change analysis and light curve modeling of the W UMa-type eclipsing binary BF Pav are presented in this *** curves of the system taken in BVRI filters from two observatories,in Australia and Argentina,were modeled using the Wilson-devinney *** results of this analysis demonstrate that BF Pav is a contact binary system with a photometric mass ratio q=1.460 ± 0.014,a fillout factor f=12.5%,an inclination of 87.97 ± 0.45 deg and a cold spot on the secondary *** applying the distance modulus formula,the distance of BF Pav was calculated to be d=268 ± 18 pc which is in good agreement with the Gaia EDR3 *** obtain an orbital period increase at a rate of 0.142 s century-1 due to a quadratic trend in the O-C ***,an alternative sudden period jump probably occurred which could be interpreted as a rapid mass transfer from the lower mass star to its companion of about ΔM=2.45 × 10-6 M⊙.Furthermore,there is an oscillatory behavior with a period of 18.3±0.3 *** BF Pav does not seem to have significant magnetic activity,this behavior could be interpreted as the light-time effect caused by an undetected third body in this *** this case,the probability for the third body to be a low mass star with M≥ 0.075 M⊙or a brown dwarf is 5.4% and 94.6% *** we assume i’=90°,a3=8.04±0.33 *** mass of the secondary component was also determined following two different methods which result close to each other.

关键词： techniques:photometric binaries:eclipsing stars:individual(BF Pav)