Browsing by Keywords "Optical pumping"

Now showing items 1-19 of 19

    • 1 mJ pulse bursts from a Yb-doped fiber amplifier 

      Kalaycıoğlu, Hamit; Eldeniz, Y. B.; Akçaalan, Önder; Yavaş Seydi; Gürel, Kutan; Efe, M.; İlday, Ömer Fatih (Optical Society of America, 2012-05)
      We demonstrate burst-mode operation of a polarization-maintaining Yb-doped fiber amplifier capable of generating 60 μJ pulses within bursts of 11 pulses with extremely uniform energy distribution facilitated by a novel ...

    • Advances in femtosecond single-crystal sum-frequency generating optical parametric oscillators 

      Köprülü, Kahraman G.; Kartaloğlu, Tolga; Dikmelik, Yamaç; Aytür, Orhan (IEEE, 1998)
      The effect of compensating the group velocity mismatch between the orthogonal pump components on the conversion efficiency of the optical parametric oscillators (OPOs) was investigated. A femtosecond single-crystal ...

    • Comparison of terahertz technologies for detection and identification of explosives 

      Beigang, R.; Biedron, S. G.; Dyjak, S.; Ellrich, F.; Haakestad, M.W.; Hübsch, D.; Kartaloglu, Tolga; Özbay, Ekmel; Ospald, F.; Palka, N.; Puc, U.; Czerwiñska, E.; Sahin, A. B.; Sešek, A.; Trontelj, J.; Švigelj, A.; Altan, H.; Van Rheenen, A.D.; Walczakowski, M. (SPIE, 2014-05)
      We present results on the comparison of different THz technologies for the detection and identification of a variety of explosives from our laboratory tests that were carried out in the framework of NATO SET-193 THz ...

    • Fiber amplification of pulse bursts up to 20 μj pulse energy at 1 kHz repetition rate 

      Kalaycıoğlu, Hamit; Eken, K.; İlday, F. Ömer (Optical of Society of America, 2011-08-23)
      We demonstrate burst-mode operation of a polarization-maintaining Yb-doped fiber amplifier. Groups of pulses with a temporal spacing of 10 ns and 1 kHz overall repetition rate are amplified to an average pulse energy of ...

    • Generation of dissipative solitons in normal-dispersion Raman fiber laser 

      Teğin, Uğur; Elahi, Parviz; Şenel, Ç.; Ergeçen, E.; İlday, Fatih Ömer (IEEE, 2016)
      Dissipative soliton pulses in a synchronously pumped all-normal-dispersion Raman fiber laser is presented theoretically and experimentally. The laser generates 7.1 nJ intra-cavity pulses at 1.12 μm and is compressed to 136 fs.

    • 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 ...

    • 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 mode-locked femtosecond Cr: LiSAF laser 

      Canbaz F.; Kakenov, N.; Kocabas, C.; Demirbas, U.; Sennaroglu, A. (Optical Society of America (OSA), 2015)
      We report the first demonstration of femtosecond pulse generation from a Cr:LiSAF laser mode-locked with a monolayer graphene saturable absorber. Nearly transform-limited 72-fs pulses were generated at 850 nm with only two ...

    • Influence of modulation of pump and seed signals on fiber amplification of broadband pulses 

      Gürel, Kutan; Elahi, Parviz; Budunoğlu, İbrahim Levent; Şenel, Çağrı; Paltani, Punya Prasanna; İlday, Fatih Ömer (OSA, 2011)
      We report on characterization of the transfer of pump and seed signal modulations, including noise, during fiber amplification. We demonstrate experimentally and theoretically that pump (signal) modulations are transferred ...

    • Influence of pump noise and modulation on in-fiber amplification of broadband pulses 

      Gürel, Kutan; Budunoğlu, İbrahim Levent; Şenel, Çağrı; Paltani, Punya Prasanna; İlday, F. Ömer (Optical Society of America, 2011)
      We investigate experimentally and theoretically the coupling of pump laser modulation and noise fluctuations to the output power of a fiber amplifier for broadband pulse trains using the modulation transfer function approach. ...

    • Low-threshold optical gain and lasing of colloidal nanoplatelets 

      Keleştemur, Yusuf; Güzeltürk, Burak; Olutaş, Murat; Delikanlı, Savaş; Demir, Hilmi Volkan (IEEE, 2014-10)
      Semiconductor nanocrystals, which are also known as colloidal quantum dots (CQDs), are highly attractive materials for high performance optoelectronic device applications such as lasers. With their size, shape and composition ...

    • Modulation behaviors, conductivities, and carrier dynamics of single and multilayer graphenes 

      Kaya, E.; Kakenov, Nurbek; Kocabaş, Coşkun; Altan, H.; Esentürk, O. (IEEE Computer Society, 2019)
      Time domain and time resolved terahertz studies of single- and multi-layer graphene (SLG and MLG) samples and modulator devices will be presented. A high performance up to 100% of modulators were observed with the devices ...

    • Multimode pumping of optical parametric oscillators 

      Marshall, L. R.; Kaz, A.; Aytur, O. (Institute of Electrical and Electronics Engineers, 1996-02)
      Calculations suggest that optical parametric oscillators (OPO's) can be efficiently pumped using multimode, divergent pump sources. The influence of pump beam divergence and mode structure upon OPO performance is measured ...

    • Nonlinearity-tailored fiber laser technology for low-noise, ultra-wideband tunable femtosecond light generation 

      Liu, X.; Laegsgaard, J.; Iegorov, R.; Svane, A. S.; Ilday, F. Ö.; Tu, H.; Boppart, S. A.; Turchinovich, D. (OSA - The Optical Society, 2017)
      The emission wavelength of a laser is physically predetermined by the gain medium used. Consequently, arbitrary wavelength generation is a fundamental challenge in the science of light. Present solutions include optical ...

    • Optical waveguides written deep inside silicon by femtosecond laser 

      Pavlov, Ihor; Tokel, Onur; Pavlova, S.; Kadan, V.; Makey, Ghaith; Turnalı, Ahmet; Çolakoğlu, T.; Yavuz, O.; İlday, Fatih Ömer (OSA, 2017)
      Summary form only given. Photonic devices that can guide, transfer or modulate light are highly desired in electronics and integrated silicon photonics. Through the nonlinear processes taking place during ultrafast ...

    • Simultaneous optical parametric oscillation and sum-frequency generation within a single crystal for converting 1064 nm into 627 nm 

      Figen, Z. Gürkan; Aytür, Orhan (IEEE, 2005-07)
      We report a 1064-nm pumped optical parametric oscillator based on a single KTiOAsO4 crystal that simultaneously generates the sum frequency of the pump and signal wavelengths, providing a 627 nm output with a high conversion ...

    • Single-crystal sum-frequency generating optical parametric oscillator 

      Köprülü, Kahraman G.; Kartaloğlu, Tolga; Aytür, Orhan (IEEE, 1997)
      A sum-frequency generating optical parametric oscillator (OPO), where a single crystal is employed for both parametric oscillation and sum frequency generation, is presented. The OPO is based on a KTiOPO4 crystal that is ...

    • Type-tunable amplified spontaneous emission from core-seeded CdSe/CdS nanorods controlled by exciton-exciton interaction 

      Kelestemur Y.; Cihan, A. F.; Guzelturk, B.; Demir, Hilmi Volkan (Royal Society of Chemistry, 2014)
      Type-tunable optical gain performance of core-seeded CdSe/CdS nanorods is studied via two-photon optical pumping. Controlling the exciton-exciton interaction by varying the core and shell size, blue-shifted and red-shifted ...

    • Warm white light generating nanocrystal hybridized LEDs with high color rendering index 

      Demir, Hilmi Volkan; Nizamoğlu, Sedat; Zengin, Güliş (IEEE, 2008-11)
      By hybridizing custom-design CdSe/ZnS core-shell NC emitters on InGaN/GaN based blue LEDs, we demonstrated three warm-white light sources with desirably low CCT ranging from 3227 K to 1982 K as is required for SSL indoor ...