Research Project: Kuantum Bilişimi için Elmas Fotonik Devrelerin Femtosaniye Lazerle Mikroüretimi, İncelenmesi, Mikroyuvar Çınlaçlarla Bağlaşımı
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Contributors
Funders
ID
TB.00202
Authors
Serpengüzel, Ali
Faculty Member
Publications
Observation of whispering-gallery modes in a diamond microsphere
(IEEE-Inst Electrical Electronics Engineers Inc, 2018) Bayer, Mustafa Mert; Çirkinoğlu, Hüseyin Ozan; Serpengüzel, Ali; Department of Physics; Graduate School of Sciences and Engineering; Microphotonics Research Laboratory; Yes; College of Sciences; GRADUATE SCHOOL OF SCIENCES AND ENGINEERING; Laboratory
We demonstrate a Type Ib diamond (nitrogen impurity of >5 ppm) microsphere whispering-gallery mode resonator in the near-infrared wavelengths between 1426.10 nm and 1427.42 nm in the 90 degrees elastic-light-scattering for both transverse magnetic (TM) and transverse electric (TE) polarizations. The highest measured whispering-gallery mode quality-factor is in the order of 10(4), and the mode spacing is 0.332 nm both for TM and TE polarizations. The coupling of the continuous-wave tunable infrared excitation laser to the diamond microsphere is achieved by a single-mode silica optical-fiber half-coupler. Such a diamond resonator can further be used as stable optical-frequency-comb generating or lasing microcavities by exploiting the nitrogen-vacancy centers present within the diamond.
Femtosecond laser written diamond waveguide excitation of the whispering gallery modes in a silicon microsphere
(Elsevier, 2019) Çirkinoğlu, Hüseyin Ozan; Serpengüzel, Ali; Bayer, Mustafa Mert; Rampini, Stefano; Sotillo, Belen; Bharadwaj, Vibhav; Ramponi, Roberta; Eaton, Shane Michael; Department of Physics; Microphotonics Research Laboratory; Yes; College of Sciences; Laboratory
We demonstrate light coupling from femtosecond laser written diamond waveguide operating at the telecommunication wavelengths to a silicon microsphere resonator. Type II waveguides are written on a diamond platform and Fahry-Perot resonances are excited in the diamond waveguides by bare fiber coupling in and out of the waveguide. The Fabry-Perot resonances have a free spectral range of 87 pm, and a maximum Q-factor of 3.9 x 10(4). The diamond waveguide is used to excite TM-polarized whispering gallery modes of the 1 mm silicon microsphere, since the type II waveguides support TM modes better as compared to TE modes. The whispering gallery mode spacing is measured as 0.257 nm and the highest Q-factor is 6.2 x 10(4). This evanescent coupling method to high Q-factor silicon microsphere resonances by femtosecond laser written diamond waveguides can be further used for filtering and sensing applications in various photonic lightwave circuits.
Spatial intensity profiling of elastic and inelastic scattering in isotropic and anisotropic liquids by immersion of a spherical silicon photocell
(The Optical Society, 2017) Bayer, Mustafa Mert; Bukhari, Syed Sultan Shah; Gökay, Ulaş Sabahattin; Humayun, Muhammad Hamza; Serpengüzel, Ali; Zakwan, Muhammad; Taira, Kenichi; Omura, Etsuji; Nakata, Josuke; Department of Physics; Microphotonics Research Laboratory; Yes; College of Sciences; Laboratory
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.
Far-infrared elastic scattering proposal for the Avogadro Project's silicon spheres
(Elsevier Ltd, 2018) Azeem, Farhan; Chaudhry, Muhammad Rehan; Gökay, Ulaş Sabahattin; Humayun, Muhammad Hamza; Khan, Imran; Murib, Mohammed Sharif; Serpengüzel, Ali; Department of Physics; Yes; College of Sciences
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.
Silicon microsphere whispering gallery modes excited by femtosecond-laser-inscribed glass waveguides
(Optical Society of America, 2018) Bayer, Mustafa Mert; Çirkinoğlu, Hüseyin Ozan; Gökay, Ulaş Sabahattin; Serpengüzel, Ali; Sotillo, Belen; Bharadwaj, Vibhav; Ramponi, Roberta; Eaton, Shane Michael; Department of Physics; Microphotonics Research Laboratory; Yes; College of Sciences; Laboratory
We report on the coupling of whispering gallery modes in a 500-mu m-radius silicon microsphere to a femtosecond-laser-inscribed glass optical waveguide. The shallow glass waveguide with a large mode field diameter in the near-infrared is written at a depth of 25 mu m below the glass surface, resulting in a high excitation impact parameter of 525 mu m for the microsphere. The excited whispering gallery modes of the silicon microsphere have quality factors of approximately 10(5) in the 90 degrees elastic scattering and 0 degrees transmission. Integration of such spherical silicon microresonators on femtosecond-laser-inscribed glass waveguides is promising for photonic communication, computation, and sensing applications. (C) 2018 Optical Society of America.
