Now showing items 1-19 of 19

    • 3.5-W, femtosecond chirped pulse amplification fiber laser system at 1560 nm 

      Elahi, Parviz; Li, Huihui; İlday, Fatih Ömer (IEEE, 2017)
      We report a single-mode, 42 MHz, 3.5-W average power chirped pulse amplification fiber laser system operating at 1560 nm. The laser system comprises a dispersion-managed mode-locked oscillator and twoamplifier stages. The ...
    • CO2 laser polishing of microfluidic channels fabricated by femtosecond laser assisted carving 

      Serhatlioglu, M.; Ortaç, B.; Elbuken, C.; Bıyıklı, Necmi; Solmaz, M. E. (Institute of Physics Publishing, 2016-10)
      In this study, we investigate the effects of CO2 laser polishing on microscopic structures fabricated by femtosecond laser assisted carving (FLAC). FLAC is the peripheral laser irradiation of 2.5D structures suitable for ...
    • Doping management for high-power fiber lasers: 100 W, few-picosecond pulse generation from an all-fiber-integrated amplifier 

      Elahi, P.; Yilmaz, S.; Akçaalan, Ö.; Kalaycioğlu, H.; Öktem, B.; Şenel, Ç.; Ilday, F. Ö.; Eken, K. (Optical Society of America, 2012-07-16)
      Thermal effects, which limit the average power, can be minimized by using low-doped, longer gain fibers, whereas the presence of nonlinear effects requires use of high-doped, shorter fibers to maximize the peak power. We ...
    • Femtosecond laser crystallization of amorphous Ge 

      Salihoglu, O.; Kürüm, U.; Yaglıoglu, G. H.; Elmali, A.; Aydınlı, Atilla (American Institute of Physics, 2011)
      Ultrafast crystallization of amorphous germanium (a-Ge) in ambient has been studied. Plasma enhanced chemical vapor deposition grown a-Ge was irradiated with single femtosecond laser pulses of various durations with a range ...
    • Femtosecond laser fabrication of fiber based optofluidic platform for flow cytometry applications 

      Serhatlioglu, Murat; Elbuken, Çağlar; Ortac, Bülend; Solmaz, Mehmet E. (SPIE, 2017)
      Miniaturized optofluidic platforms play an important role in bio-analysis, detection and diagnostic applications. The advantages of such miniaturized devices are extremely low sample requirement, low cost development and ...
    • Femtosecond laser written waveguides deep inside silicon 

      Pavlov, I.; Tokel, O.; Pavlova, S.; Kadan, V.; Makey, G.; Turnalı, A.; Yavuz, Ö.; Ilday, F. Ö. (Optical Society of America, 2017)
      Photonic devices that can guide, transfer, or modulate light are highly desired in electronics and integrated silicon (Si) photonics. Here, we demonstrate for the first time, to the best of our knowledge, the creation of ...
    • Femtosecond laser-induced TiO2 nano structures on titanium 

      Öktem, Bülent; Kalaycıoğlu, Hamit; İlday, F. Ömer (Optical Society of America, 2010)
      We report formation of polarization-dependent nanostructures (nanolines, nanocircles) by high repetition-rate femtosecond laser pulses on titanium surface through a novel mechanism, converting Ti to TiO2. Arbitrarily ...
    • Femtosecond pulse generation from an extended cavity Cr4+: Forsterite laser using graphene on YAG 

      Baylam I.; Ozharar, S.; Natali Cizmeciyan, M.; Balcı, Osman; Pince, Erçağ; Kocabaş, Coşkun; Sennaroglu, A. (Optical Society of America, 2013)
      A room temperature, multipass-cavity, femtosecond Cr4+:forsterite laser was modelocked with a single-layer graphene saturable absorber on a YAG substrate. The resonator produced nearly transform-limited 92 fs pulses near ...
    • Femtosecond self-doubling optical parametric oscillator based on KTiOAsO4 

      Kartaloğlu, T.; Aytür, O. (IEEE, 2003)
      We report a femtosecond intracavity-frequency-doubled optical parametric oscillator that employs a single KTiOAsO4 crystal for both parametric generation and frequency doubling. This device generates a yellow output beam ...
    • Generation of Sub-20-fs Pulses From a Graphene Mode-Locked Laser 

      Canbaz, F.; Kakenov, N.; Kocabas, C.; Demirbas, U.; Sennaroglu, A. (OSA - The Optical Society, 2017)
      We demonstrate, what is to our knowledge, the shortest pulses directly generated to date from a solid-state laser, mode locked with a graphene saturable absorber (GSA). In the experiments, a low-threshold diode-pumped ...
    • Geometric parametric instability of femtosecond pulses in graded-index multimode fiber 

      Teğin, Ugur; Ortaç, Bülend (Optical Society of America, 2017)
      We numerically and experimentally study the spatio-temporal femtosecond pulse evolution in graded-index multimode fiber at normal dispersion regime. We report the first demonstration of geometric parametric instability ...
    • Graphene mode-locked Cr:LiSAF laser at 850 nm 

      Canbaz F.; Kakenov, N.; Kocabas, C.; Demirbas, U.; Sennaroglu, A. (OSA - The Optical Society, 2015)
      We report, for the first time to our knowledge, a mode-locked femtosecond Cr:LiSAF laser initiated with a high-quality monolayer graphene saturable absorber (GSA), synthesized by chemical-vapor deposition. The tight-focusing ...
    • Graphene supercapacitor as a voltage controlled saturable absorber for femtosecond pulse generation 

      Baylam, I.; Çizmeciyan, M. N.; Özharar, S.; Polat, Emre Ozan; Kocabaş, Coşkun; Sennaroğlu, A. (OSA, 2014)
      For the first time to our knowledge, we employed a graphene supercapacitor as a voltage controlled saturable absorber at bias voltages of 0.5-1V to generate 84-fs pulses from a solid-state laser near 1255 nm.
    • Graphene-gold supercapacitor as a voltage controlled saturable absorber for femtosecond pulse generation 

      Baylam, I.; Balci, O.; Kakenov, N.; Kocabas, C.; Sennaroglu, A. (Optical Society of America, 2016-02)
      We report, for the first time to the best of our knowledge, use of a graphene-gold supercapacitor as a voltage controlled fast saturable absorber for femtosecond pulse generation. The unique design involving only one ...
    • An integrated femtosecond timing distribution system for XFELS 

      Kim, J.; Burnham, J.; Chen, J.; Kartner, F. X.; İlday, Fatih Ömer; Ludwig, F.; Schlarb, H.; Winter, A.; Ferianis, M.; Cheever, D. (Massachusetts Institute of Technology, 2006)
      Tightly synchronized lasers and RF-systems with timing jitter in the few femtoseconds range are necessary sub-systems for future X-ray free electron laser facilities. In this paper, we present an optical-microwave phase ...
    • Properties of a microjoule-class fiber oscillator mode-locked with a SESAM 

      Lecaplain, C.; Ortac, Bülend; MacHinet G.; Boullet J.; Baumgartl, M.; Schreiber, T.; Cormier, E.; Hideur, A. (IEEE, 2011)
      Energy scaling of ultrafast Yb-doped fiber oscillators has experienced rapid progress largely driven by many applications that require high average power femtosecond pulses. The fundamental challenge for ultrafast fiber ...
    • Spatiotemporal instability of femtosecond pulses in graded-index multimode fibers 

      Teǧin, U.; Ortaç, B. (Institute of Electrical and Electronics Engineers Inc., 2017)
      We study the spatiotemporal instability generated by a universal unstable attractor in normal dispersion graded-index multimode fiber for femtosecond pulses for the first time. Experimentally observed spatiotemporal ...
    • Spectrally breathing femtosecond pulses from an Er-doped fiber laser 

      Öktem, Bülent; Ülgüdür, Coşkun; İlday, Fatih Ömer (IEEE, 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 fs.
    • Tailoring nonlinear temperature profile in laser-material processing 

      Kesim, Denizhan Koray (Bilkent University, 2019-03)
      Ablation cooled material removal opened up great opportunities for understanding nonlinear processes. Especially using lasers as a tool to tailor nonlinear temperature gradient of material and engineering them to achieve ...