Search results for: optical dating
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1765

Search results for: optical dating

1765 Unconventional Dating of Old Peepal Tree of Chandigarh (India) Using Optically Stimulated Luminescence

Authors: Rita Rani, Ramesh Kumar

Abstract:

The intend of the current study is to date an old grand Peepal tree that is still alive. The tree is situated in Kalibard village, Sector 9, Chandigarh (India). Due to its huge structure, it has got the status of ‘Heritage tree.’ Optically Stimulated Luminescence of sediments beneath the roots is used to determine the age of the tree. Optical dating is preferred over conventional dating methods due to more precession. The methodology includes OSL of quartz grain using SAR protocol for accumulated dose measurement. The age determination of an alive tree using sedimentary quartz is in close agreement with the approximated age provided by the related agency. This is the first attempt at using optically stimulated luminescence in the age determination of alive trees in this region. The study concludes that the Luminescence dating of alive trees is the nondestructive and more precise method.

Keywords: luminescence, dose rate, optical dating, sediments

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1764 Dating Violence and Cultural Acceptance among Mexican High School Students

Authors: Libia Yanelli Yanez-Penunuri, Carlos Alejandro Hidalgo-Rasmussen, Cesar Armando Rey-Anacona

Abstract:

Cultural and social norms have a great influence on individual behavior, including the use of violence. In this way, culture can protect against violence, but it can also support and encourage the use of violence. The aim of this study was to analyze differences in cultural acceptance and dating violence among Mexican high school students. A Cross-sectional study was carried out with 867 adolescent Mexican students of high school aged 14 to 18 years old in a dating relationship for at least a month in Guzman City, Mexico. To measure cultural acceptance and dating violence, the questionnaire abuse in dating (CMO) was applied. Informed consent to parents and students was requested. Analyses of descriptive and inferential statistics were performed. Participants were adolescent girls (61.4%) and adolescent boys (38.6%). About 63.7% of adolescents reported cultural acceptance of dating violence in their dating relationships. Associations between physical, sexual, economical dating violence and cultural acceptance were found. No association was found between psychological dating violence and cultural acceptance. The effect size in all dimensions was small. For future research, it is very important to take into consideration the change and evaluation of culture norms to prevent dating violence among adolescents.

Keywords: adolescents, culture, social norms, dating violence, students

Procedia PDF Downloads 160
1763 Loving is Universal, Dating is not: Dating Experiences of International Students in Vancouver

Authors: Nel Jayson Santos

Abstract:

The growing number of international students in post-secondary institutions in Canada has positively contributed to the country’s economy and educational systems while also enriching cultural diversity in the classrooms. However, international students face social and relational challenges as they try to adapt to their host nation’s culture. One specific area of cultural adaptation among international students that has yet to be studied extensively is dating experiences and romantic relationships. Although numerous studies have been done regarding the relational challenges and dating experiences of American international students, only a few studies have focused on international students based in Canada. Hence, this study examines the dating preferences, dating challenges, and dating adaptations of international students based in Vancouver, Canada. Using a social constructivist approach, a semi-structured interview was conducted among fifteen heterosexual international college students. Inductive thematic analysis was then used to analyze the gathered data and identify common themes. Findings suggest that students’ (1) preferences were influenced by racial background and parental approval of dating partners; (2) students experienced language barriers and cultural differences; (3) students adapted through constant communication and being open-minded. Finally, the analysis intends to help counselors and psychologists in various colleges to help understand the issues of international students in terms of intimate and romantic relationships.

Keywords: higher education, international students, dating experiences, cultural adaptation

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1762 Different Cultures, Different Communication Styles: Dating Interaction in Australian and Chinese TV Dating Shows

Authors: Ping Yang

Abstract:

Dating interaction between males and females remains an interesting and mysterious event, particularly in different cultural contexts. This paper focuses on a comparative study of different communication styles males and females use while engaged in dating interaction in the Australian and Chinese contexts. Using communication accommodation theory (CAT) as an analytical framework, the researcher studies how the Australian males and females used a generally different communication style in an Australian dating show (Married at First Sight) than that used by their Chinese counterparts in a Chinese one (非诚勿扰, You Are the One). Based on the qualitative data analysis through NVivo 12 as a research tool, the researcher finds that Australian males and females generally use a divergent communication style characterized by self-orientation, directness, and confrontation, while Chinese counterparts use a convergent communication style characterized by other-orientation, indirectness, and non-confrontation. The researcher concludes with two possible reasons behind the similar TV dating event but with different dramas. One is due to different cultures with varying styles of communication, and the other is because of different drama effect designs suitable for different audience expectations in different cultural contexts.

Keywords: communication styles, cultural contexts, face-to-face interaction, TV dating.

Procedia PDF Downloads 55
1761 The Experience of Gay Men Using Dating Applications in Their Emerging Adulthood

Authors: Chuang Bing-Kai, Shih Hsiang-Ju

Abstract:

Previous studies showed that emergent adults used dating applications the most since it would satisfy their needs for intimacy. It's also found that those emergent adults were mostly non-heterosexual. What’s more, in this digital era, more and more bisexuals and homosexuals choose to establish connections with others through Internet to seek a sense of belonging. However, studies rarely focused on gay men in their emergent adulthood to explore their experiences of dating applications. The purpose of this study was to explore the experience of gay men using dating applications in their emerging adulthood and to understand their self-presentations and the process of it among different relationships while interacting with others upon using dating applications. The semi-structured interview was conducted with those gay men who aged from 18 to 29, felt attracted to people with same gender physically and mentally, considered themselves homosexual from their subjective understanding and had been using dating applications for more than half a year. Research invitations were distributed with the assistance of social media platforms and LGBTQ+ friends in the community. This study adopted a qualitative research approach and applied hermeneutic phenomenology as the method to analyze the transcripts transcribed from the recorded audio, and to explore their using experiences and self-presentations while interacting with others while using dating apps. It’s expected to find out that there are four stages in the self-presentation process including establishing personal identity, self-exploration and experimentation, exploring shared interest and values, developing and maintaining connections. Plus, gay men’s motives to use dating apps play an important role in this process and thus influence how they position the apps in their life. Through this study, professional workers can better understand gay men’s considerations and strategies in their self-presentation process as well as the impact of using motives.

Keywords: dating applications, emerging adulthood, gay men, hermeneutic phenomenology

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1760 Sediment Dating Effectiveness Using Pb210 Dating Technique at Changshou Lake in Three Gorges Reservoir Region, China

Authors: Raheel Anjum, Jinzhang Gao, Qiang Tang, Xiubin He, Xinbao Zhang, Yi Long, Zhonglin Shi, Mingfeng Wang

Abstract:

Reconstruction of the historic natural and anthropogenic effects on lake ecology has been of increasing concern to protect and improve degrading ecosystems. The dates of the Changshou Lake sediment core were estimated using Lead-210 (²¹⁰Pb) Constant rate of supply (CRS) and Constant Initial Concentration (CIC) models. While historic records such as Cesium-137 (¹³⁷Cs), C/N signals and rainfall erosivity are used as multiple proxies of the reality of the sediment profile dates. The results showed that the combined use of ¹³⁷Cs and ²¹⁰Pb chronologies using the CIC model at Changshou Lake is an effective way to address the average sedimentation rate of (1.65 cm y-1) and consistency between the estimated dates. Whereas, the CRS model estimated relatively older ages for the Changshou Lake native river bed and a misleading average sedimentation rate of (0.09 cm y-1) due to possible turbidity flows or preferential association of ²¹⁰Pb with organic matter. Alternate dating index logically reconstructed the lake ecological variations for total organic carbon, total nitrogen and carbon to nitrogen ratio with respect to historic natural and anthropogenic activities in the catchment. It can be concluded that the CIC dating model provided reliable sedimentation rate and age estimates as compared to ¹³⁷Cs and multiple proxies proposed dating index, whereas the CRS model was not suitable for dating sediment from Changshou Lake. There is a need to investigate advanced techniques for sediment dating problems at Changshou Lake.

Keywords: radiochronology, lead dating, CIC, CRS, rainfall erosivity, alternate dating

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1759 Comparison between Radiocarbon and Dendrochronology Ages Obtained on a 700 Years Tree-Ring Sequence from Northern Romania

Authors: G. Sava, I. Popa, T. Sava, A. Ion, M. Ilie, C. Manailescu, A. Robu

Abstract:

At the RoAMS laboratory in Bucharest we have looked for a head-to-head meeting between AMS radiocarbon dating and dendrochronology dating, aiming to point out and explain any differences or similarities that might appear between their output results. As a subject of this investigation, we have fixed our attention on a sequence of tree rings spanning on a period of 700 years, starting with 1000 AD. The samples were collected from the northern Romanian territory within Moldavia region, and were provided by the ‘Marin Dracea - National Institute for Research and Development in Forestry’. All the 23 single ring wood samples were radiocarbon dated using alpha-cellulose extraction, followed by graphitization in an AGE3 installation. A wiggle matching procedure was applied to reduce the radiocarbon uncertainties for the calibrated ages. The results showed a good agreement on 3 out of 4 wood cores, the age-shifting of one of the wood cores being interpreted as an uncertain dendrochronology matching, which was further corrected.

Keywords: wiggle matching, tree-ring radiocarbon dating, dendrochronology, AMS radiocarbon dating, radiocarbon dating in Romania

Procedia PDF Downloads 147
1758 Effects, Causes, and Prevention of Teen Dating Violence

Authors: Isabel Jones

Abstract:

As adolescence is a formative time, experiences during adolescence often affect the rest of one’s life. Therefore, dating, specifically violence in dating, can have lasting effects on the rest of one’s life. In order to find sources, searches were conducted on PsycINFO, specifically EBSCO, and narrowed down under the criteria that the source contained information about adolescent dating violence rather than adult, and focused on causes, effects, or prevention methods. This literature review examines research regarding the effects and causes of TDV, and then what methods are effective in the prevention of TDV development. This will allow for a clear image of how these prevention methods are effective and why they are important. Effects of TDV extend beyond the physical, including psychological and sexual long-lasting effects. These are caused by a number of concepts, including learned behavior, inhibitory issues/substance abuse, and cultural factors. When both of these are taken into account, preventative measures such as school-based interventions, parental/adult monitoring, and the presence of positive family examples are more clear as to their effectiveness. This literature review may provide further awareness to this public health crisis and give the public a view of how adolescents are affected by TDV on their path from child to adult.

Keywords: adolescence, dating violence, risk factors, predictors, relationship

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1757 Assisting Dating of Greek Papyri Images with Deep Learning

Authors: Asimina Paparrigopoulou, John Pavlopoulos, Maria Konstantinidou

Abstract:

Dating papyri accurately is crucial not only to editing their texts but also for our understanding of palaeography and the history of writing, ancient scholarship, material culture, networks in antiquity, etc. Most ancient manuscripts offer little evidence regarding the time of their production, forcing papyrologists to date them on palaeographical grounds, a method often criticized for its subjectivity. By experimenting with data obtained from the Collaborative Database of Dateable Greek Bookhands and the PapPal online collections of objectively dated Greek papyri, this study shows that deep learning dating models, pre-trained on generic images, can achieve accurate chronological estimates for a test subset (67,97% accuracy for book hands and 55,25% for documents). To compare the estimates of these models with those of humans, experts were asked to complete a questionnaire with samples of literary and documentary hands that had to be sorted chronologically by century. The same samples were dated by the models in question. The results are presented and analysed.

Keywords: image classification, papyri images, dating

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1756 Monitoring and Prediction of Intra-Crosstalk in All-Optical Network

Authors: Ahmed Jedidi, Mesfer Mohammed Alshamrani, Alwi Mohammad A. Bamhdi

Abstract:

Optical performance monitoring and optical network management are essential in building a reliable, high-capacity, and service-differentiation enabled all-optical network. One of the serious problems in this network is the fact that optical crosstalk is additive, and thus the aggregate effect of crosstalk over a whole AON may be more nefarious than a single point of crosstalk. As results, we note a huge degradation of the Quality of Service (QoS) in our network. For that, it is necessary to identify and monitor the impairments in whole network. In this way, this paper presents new system to identify and monitor crosstalk in AONs in real-time fashion. particular, it proposes a new technique to manage intra-crosstalk in objective to relax QoS of the network.

Keywords: all-optical networks, optical crosstalk, optical cross-connect, crosstalk, monitoring crosstalk

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1755 Optical Multicast over OBS Networks: An Approach Based on Code-Words and Tunable Decoders

Authors: Maha Sliti, Walid Abdallah, Noureddine Boudriga

Abstract:

In the frame of this work, we present an optical multicasting approach based on optical code-words. Our approach associates, in the edge node, an optical code-word to a group multicast address. In the core node, a set of tunable decoders are used to send a traffic data to multiple destinations based on the received code-word. The use of code-words, which correspond to the combination of an input port and a set of output ports, allows the implementation of an optical switching matrix. At the reception of a burst, it will be delayed in an optical memory. And, the received optical code-word is split to a set of tunable optical decoders. When it matches a configured code-word, the delayed burst is switched to a set of output ports.

Keywords: optical multicast, optical burst switching networks, optical code-words, tunable decoder, virtual optical memory

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1754 Enhanced Constraint-Based Optical Network (ECON) for Enhancing OSNR

Authors: G. R. Kavitha, T. S. Indumathi

Abstract:

With the constantly rising demands of the multimedia services, the requirements of long haul transport network are constantly changing in the area of optical network. Maximum data transmission using optimization of the communication channel poses the biggest challenge. Although there has been a constant focus on this area from the past decade, there was no evidence of a significant result that has been accomplished. Hence, after reviewing some potential design of optical network from literatures, it was understood that optical signal to noise ratio was one of the elementary attributes that can define the performance of the optical network. In this paper, we propose a framework termed as ECON (Enhanced Constraint-based Optical Network) that primarily optimize the optical signal to noise ratio using ROADM. The simulation is performed in Matlab and optical signal to noise ratio is extracted considering the system matrix. The outcome of the proposed study shows that optimized OSNR as compared to the existing studies.

Keywords: component, optical network, reconfigurable optical add-drop multiplexer, optical signal-to-noise ratio

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1753 Fabrication of Optical Tissue Phantoms Simulating Human Skin and Their Application

Authors: Jihoon Park, Sungkon Yu, Byungjo Jung

Abstract:

Although various optical tissue phantoms (OTPs) simulating human skin have been actively studied, their completeness is unclear because skin tissue has the intricate optical property and complicated structure disturbing the optical simulation. In this study, we designed multilayer OTP mimicking skin structure, and fabricated OTP models simulating skin-blood vessel and skin pigmentation in the skin, which are useful in Biomedical optics filed. The OTPs were characterized with the optical property and the cross-sectional structure, and analyzed by using various optical tools such as a laser speckle imaging system, OCT and a digital microscope to show the practicality. The measured optical property was within 5% error, and the thickness of each layer was uniform within 10% error in micrometer scale.

Keywords: blood vessel, optical tissue phantom, optical property, skin tissue, pigmentation

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1752 All-Optical Function Based on Self-Similar Spectral Broadening for 2R Regeneration in High-Bit-Rate Optical Transmission Systems

Authors: Leila Graini

Abstract:

In this paper, we demonstrate basic all-optical functions for 2R regeneration (Re-amplification and Re-shaping) based on self-similar spectral broadening in low normal dispersion and highly nonlinear fiber (ND-HNLF) to regenerate the signal through optical filtering including the transfer function characteristics, and output extinction ratio. Our approach of all-optical 2R regeneration is based on those of Mamyshev. The numerical study reveals the self-similar spectral broadening very effective for 2R all-optical regeneration; the proposed design presents high stability compared to a conventional regenerator using SPM broadening with reduction of the intensity fluctuations and improvement of the extinction ratio.

Keywords: all-optical function, 2R optical regeneration, self-similar broadening, Mamyshev regenerator

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1751 Characterization of Optical Communication Channels as Non-Deterministic Model

Authors: Valentina Alessandra Carvalho do Vale, Elmo Thiago Lins Cöuras Ford

Abstract:

Increasingly telecommunications sectors are adopting optical technologies, due to its ability to transmit large amounts of data over long distances. However, as in all systems of data transmission, optical communication channels suffer from undesirable and non-deterministic effects, being essential to know the same. Thus, this research allows the assessment of these effects, as well as their characterization and beneficial uses of these effects.

Keywords: optical communication, optical fiber, non-deterministic effects, telecommunication

Procedia PDF Downloads 749
1750 Study of the Optical Illusion Effects of Color Contrasts on Body Image Perception

Authors: A. Hadj Taieb, H. Ennouri

Abstract:

The current study aimed to investigate the effect that optical illusion garments have on a woman’s self-perception of her own body shape. First, we created different optical illusion garment by using color contrasts. Second, a short survey based on visual perception is addressed to women in order to compare the different optical illusion garments to determine if they met the established 'ideal' body shape. A ‘visual analysis method’ was used to investigate the clothing models with optical illusions. The theories in relation with the optical illusion were used through this method. The effects of the optical illusion of color contrast on body shape in the fashion sector were tried to be revealed.

Keywords: optical illusion, color contrasts, body image perception, self-esteem

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1749 Wavelength Conversion of Dispersion Managed Solitons at 100 Gbps through Semiconductor Optical Amplifier

Authors: Kadam Bhambri, Neena Gupta

Abstract:

All optical wavelength conversion is essential in present day optical networks for transparent interoperability, contention resolution, and wavelength routing. The incorporation of all optical wavelength convertors leads to better utilization of the network resources and hence improves the efficiency of optical networks. Wavelength convertors that can work with Dispersion Managed (DM) solitons are attractive due to their superior transmission capabilities. In this paper, wavelength conversion for dispersion managed soliton signals was demonstrated at 100 Gbps through semiconductor optical amplifier and an optical filter. The wavelength conversion was achieved for a 1550 nm input signal to1555nm output signal. The output signal was measured in terms of BER, Q factor and system margin.    

Keywords: all optical wavelength conversion, dispersion managed solitons, semiconductor optical amplifier, cross gain modultation

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1748 Tinder as a Queer Identity Building Tool: An Ethnographic Study of How Dating Apps Are Used as Identity Markers among Queer Women in Bologna, Italy

Authors: Lovis Ingrid Hakala

Abstract:

This paper provides an example of how the dating app Tinder can be used as a tool in queer research and what the use of the app among lesbians can tell us about the production of particular kinds of lesbian identities paired with technology. This study seeks to understand the ways in which the app is understood by lesbian women and how it is brought into their understandings of what being a lesbian means. Dating apps are becoming increasingly common as tools for meeting a potential partner and research has shown how these apps gain new meaning depending on the context. This paper will show both how Tinder has gained a particular meaning in a lesbian context in Bologna, and also how the use of Tinder produces specific ideas of what lesbians are and how they act. While doing ethnographic fieldwork among young lesbians (20-30 years old) in Bologna in the autumn of 2017, as a part of the research methodology, Tinder was used together with interviews and participant observation. By signing up on Tinder and contacting potential informants on the app the aim was to reach women who were not necessarily involved in the queer activist spaces in the city and who might thus provide a different perspective than their activist counterparts. Using Tinder as a tool in research proved to be a useful methodology both when it came to contacting potential informants as well as in gaining a better understanding for queer identity building, and the role Tinder played in defining lesbianism in Bologna. The app itself was often deemed useless, and informants often complained about the lack of women on the app who had their profile showing an interest in women. Apart from being away for the interlocutors to get in touch with potential romantic or sexual partners, the app did provide a concrete object around which to define particular lesbian behavior. Lesbians were described to be slow at answering and not being very eager to meet. This placed lesbian women, in contrast to gay men who were seen as doing the opposite, using dating apps a lot and be quick to propose meetings. Tinder among lesbians in Bologna thus proved to have a dual function as both a way of creating connections between queer women but also as a tool to define what a lesbian is. This paper provides insight into the ways in which dating apps provides a community and identity building function and how a certain behavior on said apps can be a part of defining identity. This work stands out among other literature on dating apps since it does not only focus on the methodological aspects of using Tinder as a tool in research but also provides an insight in how the way in which individuals use the app comes to add to an understanding of what a lesbian is.

Keywords: dating apps, identity, Italy, lesbian, queer

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1747 Optical Whitening of Textiles: Teaching and Learning Materials

Authors: C. W. Kan

Abstract:

This study examines the results of optical whitening process of different textiles such as cotton, wool and polyester. The optical whitening agents used are commercially available products, and the optical whitening agents were applied to the textiles with manufacturers’ suggested methods. The aim of this study is to illustrate the proper application methods of optical whitening agent to different textiles and hence to provide guidance note to the students in learning this topic. Acknowledgment: Authors would like to thank the financial support from the Hong Kong Polytechnic University for this work.

Keywords: learning materials, optical whitening agent, wool, cotton, polyester

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1746 Magnetic and Optical Properties of Quaternary GaFeMnN

Authors: B. Bouadjemi, S. Bentata, A. Abbad, W.Benstaali

Abstract:

The full-potential linearized augmented plane wave method (FP-LAPW) within the Generalized Gradient Approximation (GGA) is used to calculate the magnetic and optical properties of quaternary GaFeMnN. The results show that the compound becomes magnetic and half metallic and there is an apparition of peaks at low frequencies for the optical properties.

Keywords: optical properties, DFT, Spintronic, wave

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1745 Study and Analysis of Optical Intersatellite Links

Authors: Boudene Maamar, Xu Mai

Abstract:

Optical Intersatellite Links (OISLs) are wireless communications using optical signals to interconnect satellites. It is expected to be the next generation wireless communication technology according to its inherent characteristics like: an increased bandwidth, a high data rate, a data transmission security, an immunity to interference, and an unregulated spectrum etc. Optical space links are the best choice for the classical communication schemes due to its distinctive properties; high frequency, small antenna diameter and lowest transmitted power, which are critical factors to define a space communication. This paper discusses the development of free space technology and analyses the parameters and factors to establish a reliable intersatellite links using an optical signal to exchange data between satellites.

Keywords: optical intersatellite links, optical wireless communications, free space optical communications, next generation wireless communication

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1744 Theoretical Investigations on Optical Properties of GaFeMnN Quaternary Compound

Authors: H. A. Bentounes, A. Abbad, W. Benstaali

Abstract:

Using first principles calculations based on the density functional theory and local spin density approximation, we investigate optical properties of GaFeMnN quaternary compound. Results show that optical properties confirm that GaFeMnN can be a good candidate in the design of thin film solar cells in the visible and ultraviolet parts of the spectrum, and a good sensor in the infrared

Keywords: GaN, optical absorption, semi-metallic, dielectric function

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1743 Connected Objects with Optical Rectenna for Wireless Information Systems

Authors: Chayma Bahar, Chokri Baccouch, Hedi Sakli, Nizar Sakli

Abstract:

Harvesting and transport of optical and radiofrequency signals are a topical subject with multiple challenges. In this paper, we present a Optical RECTENNA system. We propose here a hybrid system solar cell antenna for 5G mobile communications networks. Thus, we propose rectifying circuit. A parametric study is done to follow the influence of load resistance and input power on Optical RECTENNA system performance. Thus, we propose a solar cell antenna structure in the frequency band of future 5G standard in 2.45 GHz bands.

Keywords: antenna, IoT, optical rectenna, solar cell

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1742 Soliton Interaction in Multi-Core Optical Fiber: Application to WDM System

Authors: S. Arun Prakash, V. Malathi, M. S. Mani Rajan

Abstract:

The analytical bright two soliton solution of the 3-coupled nonlinear Schrödinger equations with variable coefficients in birefringent optical fiber is obtained by Darboux transformation method. To the design of ultra-speed optical devices, Soliton interaction and control in birefringence fiber is investigated. Lax pair is constructed for N coupled NLS system through AKNS method. Using two soliton solution, we demonstrate different interaction behaviors of solitons in birefringent fiber depending on the choice of control parameters. Our results shows that interactions of optical solitons have some specific applications such as construction of logic gates, optical computing, soliton switching, and soliton amplification in wavelength division multiplexing (WDM) system.

Keywords: optical soliton, soliton interaction, soliton switching, WDM

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1741 The Effect of Aluminum Oxide Nanoparticles on the Optical Properties of (PVP-PEG) Blend

Authors: Hussein Hakim, Zainab Al-Ramadhan, Ahmed Hashim

Abstract:

Polymer nano composites of polyvinylpyrrolidone and poly-ethylene glycol with different concentrations of aluminum oxide (Al2O3) nano particles have been prepared by solution cast method. The optical characterizations have been done by analyzing the absorption (A) spectra in the 300–800 nm spectral region. It was found that the optical energy gap decreases with the increasing of Al2O3 nano particles content. The optical constants (refractive index, extinction coefficient, real and imaginary parts of the dielectric constant) are changing with increasing aluminum oxide nano particle concentrations.

Keywords: nanocomposites, polyvinylpyrrolidone, optical constants, polymers, blend

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1740 Semiconductor Device of Tapered Waveguide for Broadband Optical Communications

Authors: Keita Iwai, Isao Tomita

Abstract:

To expand the optical spectrum for use in broadband optical communications, we study the properties of a semiconductor waveguide device with a tapered structure including its third-order optical nonlinearity. Spectral-broadened output by the tapered structure has the potential to create a compact, built-in device for optical communications. Here we deal with a compound semiconductor waveguide, the material of which is the same as that of laser diodes used in the communication systems, i.e., InₓGa₁₋ₓAsᵧP₁₋ᵧ, which has large optical nonlinearity. We confirm that our structure widens the output spectrum sufficiently by controlling its taper form factor while utilizing the large nonlinear refraction of InₓGa₁₋ₓAsᵧP₁₋ᵧ. We also examine the taper effect for nonlinear optical loss.

Keywords: InₓGa₁₋ₓAsᵧP₁₋ᵧ, waveguide, nonlinear refraction, spectral spreading, taper device

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1739 Optical and Dielectric Properties of Self-Assembled 0D Hybrid Organic-Inorganic Insulator

Authors: S. Kassou, R. El Mrabet, A. Belaaraj, P. Guionneau, N. Hadi, T. Lamcharfi

Abstract:

The organic–inorganic hybrid perovskite-like [C6H5C2H4NH3]2ZnCl4 (PEA-ZnCl4) was synthesized by saturated solutions method. X-ray powder diffraction, Raman spectroscopy, UV-visible transmittance, and capacitance meter measurements have been used to characterize the structure, the functional groups, the optical parameters, and the dielectric constants of the material. The material has a layered structure. The optical transmittance (T %) was recorded and applied to deduce the absorption coefficient (α) and optical band gap (Eg). The hybrid shows an insulator character with a direct band gap about 4.46 eV, and presents high dielectric constants up to a frequency of about 105 Hz, which suggests a ferroelectric behavior. The reported optical and dielectric properties can help to understand the fundamental properties of perovskite materials and also to be used for optimizing or designing new devices.

Keywords: dielectric constants, optical band gap (eg), optical parameters, Raman spectroscopy, self-assembly organic inorganic hybrid

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1738 Patented Free-Space Optical System for Auto Aligned Optical Beam Allowing to Compensate Mechanical Misalignments

Authors: Aurelien Boutin

Abstract:

In optical systems such as Variable Optical Delay Lines, where a collimated beam has to go back and forth, corner cubes are used in order to keep the reflected beam parallel to the incoming beam. However, the reflected beam can be laterally shifted, which will lead to losses. In this paper, we report on a patented optical design that allows keeping the reflected beam with the exact same position and direction whatever the displacement of the corner cube leading to zero losses. After explaining how the optical design works and theoretically allows to compensate for any defects in the translation of the corner cube, we will present the results of experimental comparisons between a standard layout (i.e., only corner cubes) and our optical layout. To compare both optical layouts, we used a fiber-to-fiber coupling setup. It consists of a couple of lights from one fiber to the other, thanks to two lenses. The ensemble [fiber+lense] is fixed and called a collimator so that the light is coupled from one collimator to another. Each collimator was precisely made in order to have a precise working distance. In the experiment, we measured and compared the Insertion Losses (IL) variations between both collimators with the distance between them (i.e., natural Gaussian beam coupling losses) and between both collimators in the different optical layouts tested, with the same optical length propagation. We will show that the IL variations of our setup are less than 0.05dB with respect to the IL variations of collimators alone.

Keywords: free-space optics, variable optical delay lines, optical cavity, auto-alignment

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1737 Deflection Effect on Mirror for Space Applications

Authors: Maamar Fatouma

Abstract:

Mirror optical performance can experience varying levels of stress and tolerances, which can have a notable impact on optical parametric systems. to ensure proper optical figure and position of mirror mounting within design tolerances, it is crucial to have a robust support structure in place for optical systems. The optical figure tolerance determines the allowable deviation from the ideal form of the mirror and the position tolerance determines the location and orientations of the optical axis of the optical systems. A variety of factors influence the optical figure of the mirror. Included are self-weight (Deflection), excitation from temperature change, temperature gradients and dimensional instability. This study employs an analytical approach and finite element method to examine the effects of stress resulting from mirror mounting on the wavefront passing through the mirror. The combined effect of tolerance and deflection on mirror performance is represented by an error budget. Numerical mirror mounting is presented to illustrate the space application of performance techniques.

Keywords: opto-mechanical, bonded optic, tolerance, self-weight distortion, Rayleigh criteria

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1736 Multicasting Characteristics of All-Optical Triode Based on Negative Feedback Semiconductor Optical Amplifiers

Authors: S. Aisyah Azizan, M. Syafiq Azmi, Yuki Harada, Yoshinobu Maeda, Takaomi Matsutani

Abstract:

We introduced an all-optical multi-casting characteristics with wavelength conversion based on a novel all-optical triode using negative feedback semiconductor optical amplifier. This study was demonstrated with a transfer speed of 10 Gb/s to a non-return zero 231-1 pseudorandom bit sequence system. This multi-wavelength converter device can simultaneously provide three channels of output signal with the support of non-inverted and inverted conversion. We studied that an all-optical multi-casting and wavelength conversion accomplishing cross gain modulation is effective in a semiconductor optical amplifier which is effective to provide an inverted conversion thus negative feedback. The relationship of received power of back to back signal and output signals with wavelength 1535 nm, 1540 nm, 1545 nm, 1550 nm, and 1555 nm with bit error rate was investigated. It was reported that the output signal wavelengths were successfully converted and modulated with a power penalty of less than 8.7 dB, which the highest is 8.6 dB while the lowest is 4.4 dB. It was proved that all-optical multi-casting and wavelength conversion using an optical triode with a negative feedback by three channels at the same time at a speed of 10 Gb/s is a promising device for the new wavelength conversion technology.

Keywords: cross gain modulation, multicasting, negative feedback optical amplifier, semiconductor optical amplifier

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