The Experts below are selected from a list of 145101 Experts worldwide ranked by ideXlab platform

Jicheng Wang - One of the best experts on this subject based on the ideXlab platform.

  • a graphene based fabry perot spectrometer in mid Infrared Region
    Scientific Reports, 2016
    Co-Authors: Xiaosai Wang, Chen Chen, Jicheng Wang
    Abstract:

    Mid-Infrared spectroscopy is of great importance in many areas and its integration with thin-film technology can economically enrich the functionalities of many existing devices. In this paper we propose a graphene-based ultra-compact spectrometer (several micrometers in size) that is compatible with complementary metal-oxide-semiconductor (CMOS) processing. The proposed structure uses a monolayer graphene as a mid-Infrared surface waveguide, whose optical response is spatially modulated using electric fields to form a Fabry-Perot cavity. By varying the voltage acting on the cavity, we can control the transmitted wavelength of the spectrometer at room temperature. This design has potential applications in the graphene-silicon-based optoelectronic devices as it offers new possibilities for developing new ultra-compact spectrometers and low-cost hyperspectral imaging sensors in mid-Infrared Region.

S P Varma - One of the best experts on this subject based on the ideXlab platform.

  • Standard of Specular Reflectance at Glancing Incidence for the Infrared Region
    Metrologia, 1993
    Co-Authors: D Gupta, S P Varma
    Abstract:

    The performance of high power carbon dioxide and free electron lasers depends upon the quality of mirrors used in them. A precise characterization of mirrors is required, and this is achieved by employing reference standards. Standards for the calibration of reflectance scale for the Infrared Region are not available. The present work describes the development of a specular reflectance standard at glancing angles of incidence from 10° to 70° for the 2,5 μm to 25 μm Infrared Region. Whereas aluminium and gold mirrors have been used as high reflectance value standards, single and double surface polished silicon and germanium have been employed as standards at low reflectance values.

D Gupta - One of the best experts on this subject based on the ideXlab platform.

  • Standard of Specular Reflectance at Glancing Incidence for the Infrared Region
    Metrologia, 1993
    Co-Authors: D Gupta, S P Varma
    Abstract:

    The performance of high power carbon dioxide and free electron lasers depends upon the quality of mirrors used in them. A precise characterization of mirrors is required, and this is achieved by employing reference standards. Standards for the calibration of reflectance scale for the Infrared Region are not available. The present work describes the development of a specular reflectance standard at glancing angles of incidence from 10° to 70° for the 2,5 μm to 25 μm Infrared Region. Whereas aluminium and gold mirrors have been used as high reflectance value standards, single and double surface polished silicon and germanium have been employed as standards at low reflectance values.

M. G. Ryskin - One of the best experts on this subject based on the ideXlab platform.

  • The LHC can probe small x PDFs; the treatment of the Infrared Region
    arXiv: High Energy Physics - Phenomenology, 2013
    Co-Authors: Alan D. Martin, E. G. De Oliveira, M. G. Ryskin
    Abstract:

    First, we show how to reduce the sensitivity of the NLO predictions of the Drell-Yan production of low-mass, lepton-pairs, at high rapidity, to the choice of factorization scale. In this way, observations of this process at the LHC can make direct measurements of parton distribution functions in the low x domain; x ≲10−4. Second, we find an inconsistency in the conventional NLO treatment of the Infrared Region. We illustrate the problem using the NLO coefficient function of Drell-Yan production.

  • The treatment of the Infrared Region in perturbative QCD
    Journal of High Energy Physics, 2013
    Co-Authors: E. G. De Oliveira, Alan D. Martin, M. G. Ryskin
    Abstract:

    We discuss the contribution coming from the Infrared Region to NLO matrix elements and/or coefficient functions of hard QCD processes. Strictly speaking, this contribution is not known theoretically, since it is beyond perturbative QCD. For DGLAP evolution all the Infrared contributions are collected in the phenomenological input parton distribution functions (PDFs), at some relatively low scale Q0; functions which are obtained from a fit to the ‘global’ data. However dimensional regularization sometimes produces a non-zero result coming from the Infrared Region. Instead of this conventional regularization treatment, we argue that the proper procedure is to first subtract from the NLO matrix element the contribution already generated at the same order in α s by the LO DGLAP splitting function convoluted with the LO matrix element. This prescription eliminates the logarithmic Infrared divergence, giving a well-defined result which is consistent with the original idea that everything below Q0 is collected in the PDF input. We quantify the difference between the proposed treatment and the conventional approach using low-mass Drell-Yan production and deep inelastic electron-proton scattering as examples; and discuss the potential impact on the ‘global’ PDF analyses. We present arguments to show that the difference cannot be regarded as simply the use of an alternative factorization scheme.

V.i. Zakharov - One of the best experts on this subject based on the ideXlab platform.

  • Short strings and gluon propagator in the Infrared Region
    arXiv: High Energy Physics - Lattice, 2000
    Co-Authors: M. N. Chernodub, F. V. Gubarev, M. I. Polikarpov, V.i. Zakharov
    Abstract:

    Abstract We discuss how Infrared Region influence on short distance physics via new object, called “short string”. This object exists in confining theories and violates the operator product expansion. Most analytical results are obtained for the dual Abelian Higgs theory, while phenomenological arguments are given for QCD.

  • Short strings and gluon propagator in the Infrared Region
    Nuclear Physics B - Proceedings Supplements, 2000
    Co-Authors: M. N. Chernodub, F. V. Gubarev, M. I. Polikarpov, V.i. Zakharov
    Abstract:

    We discuss how Infrared Region influence on short distance physics via new object, called ``short string''. This object exists in confining theories and violates the operator product expansion. Most analytical results are obtained for the dual Abelian Higgs theory, while phenomenological arguments are given for QCD.Comment: LATTICE99(confine) - 6 page