Researcher:
Humayun, Muhammad Hamza

Profile Picture
ORCID

Job Title

Master Student

First Name

Muhammad Hamza

Last Name

Humayun

Name

Name Variants

Humayun, Muhammad Hamza

Email Address

Birth Date

Filters

2015 - 20183

Advanced Search

Filter by

Settings

Researcher Of Publications: search.filters.isAuthorOfPublication.19f72ff4-5309-4d09-a3f2-3a3cfb3bb553

Search Results

Now showing 1 - 3 of 3
  • Placeholder
    PublicationMetadata only
    Far-infrared elastic scattering proposal for the Avogadro Project's silicon spheres
    (Elsevier, 2018) Department of Physics; N/A; N/A; N/A; N/A; N/A; N/A; Serpengüzel, Ali; Humayun, Muhammad Hamza; Khan, Imran; Azeem, Farhan; Chaudhry, Muhammad Rehan; Gökay, Ulaş Sabahattin; Murib, Mohammed Sharif; Faculty Member; Researcher; Master Student; Researcher; Researcher; PhD Student; Researcher; Department of Physics; College of Sciences; College of Sciences; Graduate School of Sciences and Engineering; College of Sciences; College of Sciences; Graduate School of Sciences and Engineering; College of Sciences; 27855; N/A; N/A; N/A; N/A; N/A; N/A
    Avogadro constant determines the number of particles in one mole of a substance, thus relating the molar mass of the substance to the mass of this substance. Avogadro constant is related to Systeme Internationale base units by defining the very concept of chemical quantity. Revisions of the base units created a need to redefine the Avogadro constant, where a collaborative work called the Avogadro Project is established to employ optical interferometry to measure the diameter of high quality 100 mm silicon spheres. We propose far-infrared spectroscopy for determining the Avogadro constant by using elastic scattering from the 100 mm Avogadro Project silicon spheres. Similar spectroscopic methods are already in use in the near-infrared, relating whispering gallery modes of the 1 mm silicon spheres to the diameter of the spheres. We present numerical simulations in the far-infrared and the near-infrared, as well as spatially scaled down elastic scattering measurements in the near-infrared. These numerical and experimental results show that, the diameter measurements of 100 mm single crystal silicon spheres with elastic scattering in the far-infrared can be considered as an alternative to optical interferometry.
  • Placeholder
    PublicationMetadata only
    Spatial intensity profiling of elastic and inelastic scattering in isotropic and anisotropic liquids by immersion of a spherical silicon photocell
    (Optical Soc Amer, 2017) Taira, Kenichi; Omura, Etsuji; Nakata, Josuke; N/A; N/A; N/A; N/A; N/A; Department of Physics; Humayun, Muhammad Hamza; Bukhari, Syed Sultan Shah; Zakwan, Muhammad; Bayer, Mustafa Mert; Gökay, Ulaş Sabahattin; Serpengüzel, Ali; Master Student; PhD Student; PhD Student; Master Student; PhD Student; Faculty Member; Department of Physics; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Sciences; N/A; N/A; N/A; N/A; N/A; 27855
    The transverse spatial intensity distribution of elastic and inelastic light scattering in passive and active as well as weak and strong scattering liquid media has been studied by using Sphelar One p-n junction silicon spherical photocells. We immersed a Sphelar One in these scattering solutions and measured the photoconductive response in reverse biased photodiode (PD) configuration. The passive weak scattering medium was pure ethanol (EtOH), whereas the passive strong scattering medium was 5CB nematic liquid crystal (NLC). Solutions of 0.1 mM Rhodamine 640 perchlorate laser dye in EtOH and in 5CB NLC were used as active scattering media. The response of Sphelar One was strongly enhanced in 5CB NLC compared to EtOH, as well as in active solutions compared to passive solutions. The morphology of the Sphelar One is already advantageous over conventional one-sided planar PDs inside liquid solutions. This omnidirectional response of the Sphelar One can further be enhanced by optimizing the properties of the surrounding passive elastic and active inelastic scatterers.
  • Placeholder
    PublicationMetadata only
    Silicon microspheres in metrology
    (Electromagnetics Academy, 2015) N/A; N/A; N/A; N/A; N/A; Department of Physics; Humayun, Muhammad Hamza; Azeem, Farhan; Khan, Imran; Gökay, Ulaş Sabahattin; Serpengüzel, Ali; Master Student; Master Student; Master Student; PhD Student; Faculty Member; Department of Physics; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Sciences; N/A; N/A; N/A; N/A; 27855
    The Système International unit of mass is the kilogram. The present definition of the kg is based on a prototype dating back to 1880s. New approaches to define the unit of mass are being investigated. Avogadro Project uses 10 cm diameter single crystal silicon spheres. The technique commonly observed to measure the radius of the silicon sphere is optical interferometry. Here, we propose an alternate method of measuring the diameter of the single crystal silicon sphere using near-infrared spectroscopy. We demonstrate our approach by numerically simulating the electromagnetic coupling of a silicon microdisk of radius 5 µm to an optical waveguide of width 0.5 µm, thereby approximating the coupling of a microsphere to a rectangular optical waveguide. It might be possible to have a precise technique for determining the radius of the sphere, which can be used for the definition of the kilogram.