Journal of lasers, optics & photonics最新文献

{"title":"Phase stability in next-generation atomic frequency standards","authors":"D. Howe","doi":"10.4172/2469-410X-C1-019","DOIUrl":"https://doi.org/10.4172/2469-410X-C1-019","url":null,"abstract":"Atomic clocks (or oscillators) formthe basis of standard, everyday timekeeping. Separated, hi-accuracy clocks can maintain nanosecond-level autonomous synchronization for many days. The world’s best Cs time standards are atomic fountains that use a RF quantum transition at 9,192,631,770 Hz and reach total frequency uncertainties of 2.7 – 4 × 10​ with many days of averaging time. But 1 the days of averaging prohibit real-time use of this accuracy, and even the accuracy of today’s commercial Cs of a few × 10​. A new class of optical atomic standards with quantum transitions having ​+​1 × 10​ uncertainty at ~200 THz, which is inconvenient for applications, drives an optical frequency-comb divider (OFD), thus providing exceptional phase stability, or ultra-low phase noise (ULPN), at convenient RF frequencies. Most importantly, this scheme produces exquisite ​real-time accuracy​ at RF, as in the previous example of a few × 10​ accuracy, as quickly as fractions of a second. This single property elevate their usage to a vast array of applications that extend far beyond everyday timekeeping. “Accuracy” is the agreement with a standard realization of a reference, carrier, or local oscillator (LO) frequency. “Phase stability” quantifies the precision with which we can determine frequency as a function of averaging time in the time domain or phase noise in the frequency domain, a single-sideband (SSB) measurement of noise denoted as ​L​(​f​). The ​L​(​f​) measurement is used in virtually all technology sectors because it fully decomposes and describes phase instability, or phase noise, into all of its components at an offset-frequency from the carrier on a frequency-by-frequency basis. I show how accurate oscillators with low-phase noise dramatically improves: (1) position, navigation, and timing; (2) high-speed communications, (3) private messaging and cryptology, and (4) spectrum sharing. This talk outlines game-changing possibilities in these four areas, given next-generation, nearly phase-noise free, quantum-based (or atomic) frequency generators with ​+​1 x 10​ accuracy whose properties are sustained across an application’s environmental range. I show how the combination of high atomic accuracy and low-phase noise coupled with reduced size, weight, and power usage pushes certain limits of physics to unlock a new paradigm – creating networks of separated oscillators that maintain extended phase coherence, or a virtual lock, with no means of synchronization whatsoever except at the start. “Phase coherence” means that separate oscillators maintain at least 0.1 rad phase difference at a common, or normalized, carrier frequency for long periods after synchronization. Quantum-based fractional-frequency accuracy within ​+​1 × 10​ when combined with equally low-phase noise synchronization at 1 × 10​ (1 fs in 1 s), means the relative phase difference increases only as ​√τ​ · 10​ · carrier frequency (ω​о​). In terms of time, this means that a 1 ns time differenc","PeriodicalId":92245,"journal":{"name":"Journal of lasers, optics & photonics","volume":"319 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77135148","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}

{"title":"Motley string or from 10 to 4","authors":"G. Matveev","doi":"10.4172/2469-410X.1000190","DOIUrl":"https://doi.org/10.4172/2469-410X.1000190","url":null,"abstract":"In 1926 O. Klein proposed [5] that extra spacial dimension in Kaluza theory got curled up in a circle of small radius (aka \"compactified\"). Same idea applied to Superstring theory means that some spacial dimensions (6) are compactified, while others (3) are not, which leaves unanswered question why some dimensions are better then others. Also it implies the existence of standing waves in compactified dimensions (so called Kaluza-Klein tower) which are not observed experimentally.","PeriodicalId":92245,"journal":{"name":"Journal of lasers, optics & photonics","volume":"3 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2018-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82714563","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}

{"title":"Laser Technology to Guide Rainfall to a Particular Region","authors":"Subramaniam Tk","doi":"10.4172/2469-410X.1000173","DOIUrl":"https://doi.org/10.4172/2469-410X.1000173","url":null,"abstract":"Rain bearing clouds can be effectively guided to a specific region during monsoon or other seasons so that rainfall shall be equitably distributed without creating drought situations. Lasers sent into the lower troposphere region with intensities sufficient to create a temperature gradient and thereby creating a low pressure area in a specific region can invite rain bearing clouds to a region opposite to where heat is generated by laser effect, so as to bring convective rainfall during a season","PeriodicalId":92245,"journal":{"name":"Journal of lasers, optics & photonics","volume":"1155 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2018-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72701281","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}

{"title":"Deuteron States Model","authors":"G. He","doi":"10.4172/2469-410X.1000172","DOIUrl":"https://doi.org/10.4172/2469-410X.1000172","url":null,"abstract":"","PeriodicalId":92245,"journal":{"name":"Journal of lasers, optics & photonics","volume":"44 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87006355","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}

{"title":"Infrared Laser Excitation to Study Transitions in Fullerene (C60) Molecule","authors":"Subramaniam Ty, P. Premanand","doi":"10.4172/2469-410X.1000189","DOIUrl":"https://doi.org/10.4172/2469-410X.1000189","url":null,"abstract":"Raman spectroscopy is the study of inelastic scattering of light. A Raman active sample should show a change in polarizability. It provides amongst other things, important information about the vibrational state of matter. Raman studies in scattering entails a sum of both creation and annihilation of photons and law of energy conservation applies to only the overall process and not to individual events. Infrared laser beam is a good choice for studying absorption and emission characteristics of fullerene molecule. The photo physical, photochemical and optical properties have already been studied in detail by many scientists. We intend to study the infrared laser induced characteristics of fullerene molecule. It is expected that laser interaction with C60 molecule can break the carbon bond, creating more free electrons resulting in formation of new compounds. Citation: Subramaniam TY, Premanand P (2018) Infrared Laser Excitation to Study Transitions in Fullerene (C60) Molecule. J Laser Opt Photonics 5: 189. doi: 10.4172/2469-410X.1000189","PeriodicalId":92245,"journal":{"name":"Journal of lasers, optics & photonics","volume":"4 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87728959","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}

{"title":"Synthesis and Electrical Transport Properties of CuInGaTe2","authors":"Salem A, Salwa As, Hussein Sa, Ezzeldien M","doi":"10.4172/2469-410X.1000183","DOIUrl":"https://doi.org/10.4172/2469-410X.1000183","url":null,"abstract":"Copper Indium Gallium di-telluride (CIGT) single crystals were synthesized by a special modified Bridgman technique for crystal growth. Our XRD patterns clearly exhibited single phase. The temperature dependence of the electrical conductivity σ(T), Hall coefficient RH(T) in CuInGaTe2 single crystals have been demonstrated over the temperature range 143-558 K for the first time. The Hall coefficient sign confirms the samples displays the p-type conducting. The temperature dependence of the conductivity, Hall coefficient, Hall mobility, and charge carriers concentration were investigated were presented with a clear and effective pictures. CuInGaTe2 single crystals revealed electrical band gaps (or \"transport gaps\") ranging from 0.64 eV to 0.85 eV. The results obtained from electrical conductivity and carrier concentration revealed the sample p-type with acceptor energy level equal to ≈ 0.027 eV. From the obtained experimental data, the main fundamental physical constants and others for crystals under consideration have been estimated.","PeriodicalId":92245,"journal":{"name":"Journal of lasers, optics & photonics","volume":"34 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80808059","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}

{"title":"Nonlinear mean-field versus linear quantum electrodynamics descriptions of a two-particle interacting bound-state quantum system","authors":"G. Reinisch","doi":"10.4172/2469-410X-C3-030","DOIUrl":"https://doi.org/10.4172/2469-410X-C3-030","url":null,"abstract":"","PeriodicalId":92245,"journal":{"name":"Journal of lasers, optics & photonics","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82134475","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}

{"title":"Synthesis, Structural, Spectral, Optical and Mechanical Study of Benzimidazolium Phthalate crystals for NLO Applications","authors":"S. N., A. B, A. Kumar R, Mathammal R","doi":"10.4172/2469-410X.1000184","DOIUrl":"https://doi.org/10.4172/2469-410X.1000184","url":null,"abstract":"Organic nonlinear crystal benzimidazolium phthalate have been grown by slow evaporation solution growth technique. The crystal belongs to orthorhombic crystal system space group P21. The functional groups present in the crystal were identified by FT-IR spectrum. The UV-Visible spectrum study reveals that the crystal has excellent transmittance the cut-off region being 205 nm. The photoluminescence spectrum shows violet emission. The chromaticity coordinates are calculated from the emission spectra and the emission intensity of the grown crystal is characterized through color chromaticity diagram. Dielectric studies find a way for the crystal to be used for opto electronic devices. Vicker’s hardness test shows its mechanical behavior. The NLO property was confirmed by green emission in SHG test. Figure 1: As grown crystal of BPA by slow evaporation method. Citation: Sudha N, Abinaya B, Arun Kumar R, Mathammal R (2018) Synthesis, Structural, Spectral, Optical and Mechanical Study of Benzimidazolium Phthalate crystals for NLO Applications. J Laser Opt Photonics 5: 184. doi: 10.4172/2469-410X.1000184","PeriodicalId":92245,"journal":{"name":"Journal of lasers, optics & photonics","volume":"49 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79211341","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}

{"title":"The NiO nanorode formation and its activate photocatalist by reduced graphene oxide","authors":"A. Yazdani, K. Rahimi","doi":"10.4172/2469-410X-C4-033","DOIUrl":"https://doi.org/10.4172/2469-410X-C4-033","url":null,"abstract":"","PeriodicalId":92245,"journal":{"name":"Journal of lasers, optics & photonics","volume":"05 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88841753","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}

{"title":"A Quantum Field Approach for Advancing Optical Coherence Tomography Part I: First Order Correlations, Single Photon Interference, and Quantum Noise.","authors":"M E Brezinski","doi":"10.4172/2469-410X.1000176","DOIUrl":"https://doi.org/10.4172/2469-410X.1000176","url":null,"abstract":"<p><p>Optical coherence tomography has become an important imaging technology in cardiology and ophthalmology, with other applications under investigations. Major advances in optical coherence tomography (OCT) imaging are likely to occur through a quantum field approach to the technology. In this paper, which is the first part in a series on the topic, the quantum basis of OCT first order correlations is expressed in terms of full field quantization. Specifically first order correlations are treated as the linear sum of single photon interferences along indistinguishable paths. Photons and the electromagnetic (EM) field are described in terms of quantum harmonic oscillators. While the author feels the study of quantum second order correlations will lead to greater paradigm shifts in the field, addressed in part II, advances from the study of quantum first order correlations are given. In particular, ranging errors are discussed (with remedies) from vacuum fluctuations through the detector port, photon counting errors, and position probability amplitude uncertainty. In addition, the principles of quantum field theory and first order correlations are needed for studying second order correlations in part II.</p>","PeriodicalId":92245,"journal":{"name":"Journal of lasers, optics & photonics","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4172/2469-410X.1000176","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40439898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}