Now showing items 1-20 of 24

    • 83 W, 1 ns, 3.1 MHz all-fiber laser for micromachining 

      Özgören, K.; Oktem, B.; Yilmaz, S.; Ömer Ilday F.; Pasin, E.; Eken, K. (2011)
      Fiber lasers are commonly used for various material processing applications. The advantages (such as simplicity of the system, high material removal rate) and disadvantages (larger heat-affected zone, reduced precision) ...
    • All-fiber nonlinearity-and dispersion-managed dissipative soliton nanotube mode-locked laser 

      Zhang Z.; Popa, D.; Wittwer, V. J.; Milana, S.; Hasan, T.; Jiang, Z.; Ferrari, A. C.; Ilday F. Ö. (American Institute of Physics, 2015)
      We report dissipative soliton generation from an Yb-doped all-fiber nonlinearity- and dispersion-managed nanotube mode-locked laser. A simple all-fiber ring cavity exploits a photonic crystal fiber for both nonlinearity ...
    • Development and investigation of high power ytterbium-doped fiber lasers operating At 1018 nm 

      Efunbajo, Oyewole Benjamin (Bilkent University, 2017-07)
      The development of ytterbium-doped ber lasers (YDFL) operating around 1018 nm with two major pumping schemes are reported. The study on the developed all ber lasers were characterized based on parameters such as ...
    • Development of high power Cw Yb-Doped fiber laser system 

      Özkan, Elif Gül (Bilkent University, 2015-01)
      High-average-power fiber lasers are interesting for many applications, including scientific instrumentation, industrial material processing, imaging, medical and military technologies. Fiber concept has well established ...
    • Effects of laser ablated silver nanoparticles on Lemna minor 

      Üçüncü, E.; Özkan, A. D.; Kurşungöz, C.; Ülger, Z. E.; Ölmez, T. T.; Tekinay, T.; Ortaç, B.; Tunca E. (Elsevier, 2014)
    • Enhancement and inhibition of photoluminescence in hydrogenated amorphous silicon nitride microcavities 

      Serpenguzel, A.; Aydinli, A.; Bek, A. (Optical Society of America, 1997-09-01)
      A Fabry-Perot microcavity is used for the enhancement and inhibition of photoluminescence in hydrogenated amorphous silicon nitride. The amplitude of the photoluminescence is enhanced 4 times, while its linewidth is reduced ...
    • Femtosecond optical parametric oscillator based on periodically poled KTiOPO4 

      Kartaloğlu, T.; Köprülü, K. G.; Aytür, O.; Sundheimer, M.; Risk, W. P. (1998-01-01)
      We report a femtosecond optical parametric oscillator based on a periodically poled KTiOPO4 crystal for which quasi-phase matching is achieved with a 24-μm poling period. The singly resonant parametric oscillator, synchronously ...
    • High-Q silicon-on-insulator optical rib waveguide racetrack resonators 

      Kiyat I.; Aydinli, A.; Dagli, N. (Optical Society of American (OSA), 2005)
      In this work, detailed design and realization of high quality factor (Q) racetrack resonators based on silicon-on-insulator rib waveguides are presented. Aiming to achieve critical coupling, suitable waveguide geometry is ...
    • InGaN/GaN light-emitting diode with a polarization tunnel junction 

      Zhang Z.-H.; Tan S.T.; Kyaw, Z.; Ji Y.; Liu W.; Ju, Z.; Hasanov N.; Sun, X. W.; Demir, H. V. (American Institute of Physics, 2013)
      We report InGaN/GaN light-emitting diodes (LED) comprising in situ integrated p(+)-GaN/InGaN/n(+)-GaN polarization tunnel junctions. Improved current spreading and carrier tunneling probability were obtained in the proposed ...
    • Laser action studies of φ-conjugated polymer microcavities 

      Tulek, A.; Vardeny, Z.V. (2008)
      Unidirectional laser emission was observed from φ-conjugated polymer microcavities with spiral geometry, and from microdisks containing line defects. For both type of cavities directionality contrast of the laser emission ...
    • Lasing in a Slow Plasmon Moiré Cavity 

      Karademir, E.; Balci, S.; Kocabas, C.; Aydinli, A. (American Chemical Society, 2015)
      We report on lasing from dye-based excitons coupled to slow plasmon states inside metallic Moiré cavities. Surface plasmon polaritons (SPPs) inside the cavity were slowed down to a maximum group velocity of 0.3c. Varying ...
    • Multiplex systems for the amplification of short tandem repeat loci: evaluation of laser fluorescence detection 

      Ricciardone, M. D.; Lins, A. M.; Schumm, J. W.; Holland, M. M. (1997)
      Short tandem repeat (STR) loci are ideal markers for personal identification and for genomic mapping. Two fluorescent multiplex systems, each designed for simultaneous PCR amplification of four polymorphic STR loci (HUMCSF1PO, ...
    • Negative refraction and focusing by a left-handed material slab in free space 

      Aydin, K.; Ozbay, E. (2006)
      Negative refraction and focusing by a left-handed metamaterial (LHM) slab are experimentally verified. We measured refractive index of slab as -1.86. The flat lens behavior of LHM is demonstrated for two different point ...
    • Nonlinear chirped-pulse amplification of a soliton-similariton laser to ~1 µJ at 1550 nm 

      İlbey, Emrah; Pavlov, Ihor; Dülgergil, E.; Öktem, Bülent; Yavas, Seydi; Rybak, Andrii; Zhang, Zuxing; İlday, Fatih Ömer (Optical Society of America, 2012)
      We demonstrate all-fiber-integrated nonlinear CPA system operating at 1550 nm, seeded by a soliton-similariton laser. Chirped 2-μJ pulses are compressed to 700-fs, 0.5-μJ pulses at 1 MHz. Amplifier output is through a ...
    • Operation of a novel hot electron vertical cavity surface emitting laser 

      Balkan, N.; O'Brien-Davies, A.; Thoms, A. B.; Potter, R. J.; Poolton, N.; Adams, M. J.; Masum J.; Bek, A.; Serpenguzel, A.; Aydinli, A.; Roberts J. S. (SPIE - The International Society for Optical Engineering, 1998-01)
      The hot Electron Light Emission and Lasing in Semiconductor Heterostructures devices (HELLISH-1) is novel surface emitter consisting of a GaAs quantum well, within the depletion region, on the n side of Ga 1-xAlxAs p- n ...
    • Physics and applications of photonic nanocrystals 

      Ozbay E.; Guven K.; Aydin K.; Bayindir M. (2004)
      Photonic nanocrystals are periodic dielectric or metallic structures having photonic bands in analogy to electronic bands of semiconductors. The presence of photonic band-gaps, where the propagation of photons of certain ...
    • A plasmonic enhanced photodetector based on silicon nanocrystals obtained through laser ablation 

      Alkis, S.; Oruç, F. B.; Ortaç, B.; Koşger, A. C.; Okyay, A., K. (Institute of Physics Publishing, 2012-10-18)
      We present a proof-of-concept photodetector which is sensitive in the visible spectrum. Silicon nanocrystals (Si-NCs) obtained by laser ablation are used as the active absorption region. Si-NC films are formed from a ...
    • Spectrally breathing femtosecond pulses from an Er-doped fiber laser 

      Oktem, B.; Ülgüdür, C.; Ilday, F. Ö. (2008)
      We report order-of-magnitude spectral breathing in a dispersion-managed Er-fiber laser with an intracavity bandpass filter. This is to our knowledge the highest of any laser reported. Pulse energy is 1.7 nJ, width is 110 ...
    • Study of strong turbulence effects for optical wireless links 

      Yuksel, H.; Meric, H.; Kunter, F. (S P I E - International Society for Optical Engineering, 2012)
      Strong turbulence measurements that are taken using real time optical wireless experimental setups are valuable when studying the effects of turbulence regimes on a propagating optical beam. In any kind of FSO system, for ...
    • Texturing of titanium (Ti6Al4V) medical implant surfaces with MHz-repetition-rate femtosecond and picosecond Yb-doped fiber lasers 

      Erdoǧan, M.; Öktem, B.; Kalaycioǧlu H.; Yavaş, S.; Mukhopadhyay P.K.; Eken, K.; Özgören, K.; Aykaç, Y.; Tazebay, U.H.; Ilday F.O. (Optical Society of American (OSA), 2011)
      We propose and demonstrate the use of short pulsed fiber lasers in surface texturing using MHz-repetition-rate, microjoule- and sub-microjoule-energy pulses. Texturing of titanium-based (Ti6Al4V) dental implant surfaces ...