Browsing NTNU Open by Author "Tolstik, Nikolai"

Now showing items 21-40 of 49

    • Femtosecond laser writing of the depressed cladding buried channel waveguides in ZnS crystal 

      Okhrimchuk, A.; Smayev, M.; Likhov, V.; Sorokin, Evgeni; Tolstik, Nikolai; Sorokina, Irina T (Chapter, 2018)
      We report the first direct laser-writing of buried channel waveguides in ZnS. A depressed cladding waveguide with propagation loss of 0.62 dB/cm at 1030 nm allowed to obtain spectral broadening under femtosecond-pumping ...

    • Femtosecond operation and self‐doubling of Cr:ZnS laser 

      Sorokin, Evgeni; Sorokina, Irina T; Tolstik, Nikolai (Chapter, 2011)
      Prismless dispersion‐controlled Cr:ZnS laser generates first femtosecond (110 fs) pulses at 180 MHz repetition rate around 2400 nm with average power 200 mW. Copropagating second‐harmonic pulse at 1200 nm is simultaneously ...

    • Femtosecond SESAM-modelocked Cr:ZnS laser 

      Sorokin, Evgeni; Tolstik, Nikolai; Schaffers, Kathleen I.; Sorokina, Irina T (Journal article; Peer reviewed, 2012)
      We report self-starting femtosecond operation of a 180-MHz SESAM-controlled prismless Cr:ZnS laser around 2400 nm at open air and room temperature. Dispersion compensation was achieved by a combination of bulk materials ...

    • Flat-top supercontinuum and tunable femtosecond fiber laser sources at 1.9-2.5 μm 

      Klimentov, Dmitry; Tolstik, Nikolai; Dvoyrin, Vladislav V; Richter, Roland Axel; Sorokina, Irina T (Journal article; Peer reviewed, 2016)
      We report the high-energy flat-top supercontinuum covering the midinfrared wavelength range of 1.9-2.5 μm as well as electronically tunable femtosecond pulses between 1.98 and 2.22 μm directly from the thulium-doped fiber ...

    • Gigahertz Femtosecond Cr:ZnS Laser 

      Tolstik, Nikolai; Evgeni, Sorokin; Sorokina, Irina T. (Chapter, 2014)
      We demonstrate the first Cr:ZnS laser with a gigahertz pulse repetition rate. The passively mode-locked by the graphene-based mirror laser provides 105 mW output power with 180 fs pulse duration and 110 pJ pulse energy.

    • Graphene mode-locked Cr: ZnS chirped-pulse oscillator 

      Tolstik, Nikolai; Pospischil, Andreas; Sorokin, Evgeni; Sorokina, Irina T (Journal article; Peer reviewed, 2014)
      We report the first to our knowledge high-energy graphene mode-locked solid-state laser operating in the positive dispersion regime. Pulses with 15.5 nJ energy and 42 nm spectral bandwidth with 0.87 ps duration were obtained ...

    • Graphene Mode-locked Cr:ZnS Laser with 41 fs Pulse Duration 

      Tolstik, Nikolai; Sorokin, Evgeni; Sorokina, Irina T (Journal article; Peer reviewed, 2014)
      We report the ultrashort-pulse Cr:ZnS laser mode-locked by graphene-based saturable absorber mirror. Using the combination of bulk material and a chirped mirror, we demonstrate the shortest reported so far mid-IR pulses ...

    • Graphene mode-locked Cr:ZnS laser with 44 fs pulse duration 

      Tolstik, Nikolai; Pospischil, Andreas; Sorokin, E.; Sorokina, Irina T (Chapter, 2013)
      The first Cr:ZnS laser mode-locked by graphene-based saturable absorber mirror generates the shortest reported so far mid-IR pulses of only 5.5 optical cycles (44 fs) at 2.35 μm with 139 nm spectral bandwidth.

    • Graphene-mode-locked Holmium Fiber Laser Operating Beyond 2.1 µm 

      Dvoyrin, Vladislav; Tolstik, Nikolai; Sorokin, E.; Sorokina, Irina T; Kurkov, A. (Chapter, 2015)

    • High energy 2.1 micron short-pulsed fiber MOPA laser 

      Skogen, Marius (Master thesis, 2019)
      Denne master oppgaven er sammensatt av flere eksperimenter og numeriske modeller som sammen har ført til utviklingen av en ny kort-pulset, høy energi diode bassert Holmium "Master Oscillator Power Amplifier (MOPA)" laser ...

    • High Energy Broadband Femtosecond Pulse Generation From Tm-doped Fiber MOPA 

      Klimentov, Dmitry; Dvoyrin, Vladislav; Tolstik, Nikolai; Sorokina, Irina T (Chapter, 2016)
      We report generation of high energy (up to 280 nJ), broadband (over 450 nm between 1.95 - 2.4 µm), 200 fs pulses at 2.1 W average power directly from a Tm-fiber MOPA laser.

    • High-energy Mid-Infrared Cr:ZnS Chirped-pulse oscillator 

      Tolstik, Nikolai; Sorokin, Evgeni; Sorokina, Irina T (Chapter; Peer reviewed, 2013)
      Femtosecond coherent light sources emitting in the mid-infrared are of particular interest for a number of applications like environmental sensing, medicine, metrology, material processing and telecommunications. Among the ...

    • Kerr-Lens Mode-locked Cr:ZnS Laser 

      Sorokin, Evgeni; Tolstik, Nikolai; Sorokina, Irina T (Chapter, 2012)
      The first Kerr-Lens mode-locked Cr:ZnS laser generates the shortest and highest-energy mid-IR near transform-limited pulses of 69 fs duration at 550 mW output power. The 3.7 nJ pulses have 193 nm wide spectrum around 2.39 µm

    • Kerr-lens mode-locked Cr:ZnS laser 

      Tolstik, Nikolai; Sorokin, Evgeni; Sorokina, Irina T (Journal article; Peer reviewed, 2013)
      We report the soft-aperture Kerr-lens mode-locked Cr:ZnS laser, generating 550 mW of 69 fs nearly transform-limited pulses at 2.39 μm wavelength. The pulse energy reached 3.8 nJ at 145 MHz repetition rate, limited by the ...

    • MBE-grown Cr:ZnS Thin Film Laser Media 

      Tolstik, Nikolai; Sorokin, Evgeni; Karhu, Eric Andrew; Polyakov, Stanislav; Gibson, Ursula; Sorokina, Irina T (Chapter, 2016)
      We report results of spectroscopic analysis of the first first laser-quality MBE-grown Cr:ZnS films. Comparison of spectral-luminescent properties with bulk Cr:ZnS indicates their good laser properties, opening the way ...

    • Mid-Infrared Femtosecond Laser 

      Sorokin, E.; Tolstik, Nikolai; Sorokina, Irina T (Chapter, 2013)
      Recent breakthroughs in femtosecond lasers operating directly in the mid-infrared wavelength region enabled generation of Watt-level output with ~10-nJ pulses and only 5 optical cycles duration, demonstrating interesting ...

    • Mid-IR ultrashort pulsed fiber-based lasers 

      Sorokina, Irina T; Dvoyrin, Vladislav; Tolstik, Nikolai; Sorokin, Evgeni (Journal article; Peer reviewed, 2014)
      We review the latest breakthroughs in ultrafast fiber laser technology in the mid-IR wavelength range ≥2 μm. In particular, we concentrate on two novel laser systems built around passively mode-locked Tm:fiber lasers and ...

    • Nonlinear Propagation of mid-IR Femtosecond Pulses in ZBLAN Fiber 

      Tolstik, Nikolai; Sorokin, Evgeni; Kalashnikov, Vladimir; Sorokina, Irina T (Chapter, 2012)
      We demonstrate environmentally protected delivery of high-power femtosecond mid-IR pulses in a single-mode ZBLAN fiber by soliton formation. A 70-fs Cr:ZnS laser at 2.4 µm reaches this regime already at ~1.5 nJ launched ...

    • Octave-spanning Supercontinuum From As2S3-silica Double-nanospike Waveguide Pumped by Femtosecond Cr:ZnS Laser at 2.35 μm 

      Tolstik, Nikolai; Xie, Shangran; Sorokin, E.; Travers, J.; Troles, J.; Russell, Philip; Sorokina, Irina T (Chapter, 2015)
      We generate a 1.2 to 3.6 μm supercontinuum using a As2S3-silica double-nanospike waveguide pumped by femtosecond Cr:ZnS laser. Varying the core diameter allows the group velocity dispersion to be fine-tuned, thus maximizing ...

    • Optical Coatings as Active Media for Mid-Infrared lasers 

      Karhu, Eric Andrew; Tolstik, Nikolai; Sorokin, Evgeni; Furtula, Vedran; Sorokina, Irina T.; Gibson, Ursula (Chapter, 2016)
      Thin films of Cr and Fe-doped ZnS with high infrared transparency have been deposited by molecular beam epitaxy and show optical properties suitable for use as active media in mid-infrared laser applications.