Blar i Institutt for fysikk på forfatter "Kalashnikov, Vladimir"

Viser treff 1-11 av 11

    • Atmospheric dispersion management in mid-IR mode-locked oscillators 

      Sorokin, Evgeni; Rudenkov, Alexander; Tolstik, Nikolai; Kalashnikov, Vladimir; Demesh, Maksim; Sorokina, Irina (Peer reviewed; Journal article, 2023)
      The atmospheric dispersion in the mid-infrared transparency windows presents an important albeit often neglected factor when developing ultrashort-pulsed lasers. We show that it can amount to hundreds of fs2 in 2–3 µm ...

    • Chaotic chirped-pulse oscillators 

      Sorokin, Evgeni; Tolstik, Nikolai; Kalashnikov, Vladimir; Sorokina, Irina T (Journal article; Peer reviewed, 2013)
      We present results of experimental investigation of the chaotic and quasi-periodic regime in the chirped-pulsed (dissipative soliton) Cr:ZnS and Cr:ZnSe mid-IR oscillators with significant third-order dispersion. The ...

    • Continuum generation in Mid-IR from Tm-doped germanate fiber using femtosecond Cr:ZnS laser 

      Tolstik, Nikolai; Klimentov, Dmitry; Dvoyrin, Vladislav; Sorokina, Irina T; Kalashnikov, Vladimir; Sorokin, Evgeni (Chapter, 2012)
      The mid-IR supercontinuum generation in fibers has received much attention due to its broad applicability to high-resolution spectroscopy and trace gas analysis, frequency metrology and optical coherence tomography (OCT). ...

    • High peak power and energy scaling in the mid-IR chirped-pulse oscillator-amplifier laser systems 

      Rudenkov, Alexander; Kalashnikov, Vladimir; Sorokin, Evgeni; Demesh, Maksim; Sorokina, Irina (Peer reviewed; Journal article, 2023)
      The paper introduces a new route towards the ultrafast high laser peak power and energy scaling in a hybrid mid-IR chirped pulse oscillator-amplifier (CPO-CPA) system, without sacrificing neither the pulse duration nor ...

    • 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 ...

    • Rotational Curves of the Milky Way Galaxy and Andromeda Galaxy in Light of Vacuum Polarization around Eicheon † 

      Cherkas, Sergey L.; Kalashnikov, Vladimir (Peer reviewed; Journal article, 2023)
      Eicheon properties are discussed. It is shown that the eicheon surface allows setting a boundary condition for the vacuum polarization and obtaining a solution describing the dark matter tail in the Milky Way Galaxy. That ...

    • Soliton absorption spectroscopy in normal-dispersion lasers 

      Kalashnikov, Vladimir; Sorokin, Evgeni; Sorokina, Irina T (Chapter, 2010)
      An all-normal-dispersion oscillator with narrowband intracavity absorption acquires spectral features which follow the index of refraction of the absorber, as confirmed by experimental obsevation. Compared to the conventional ...

    • Spectral Broadening of mid-IR Femtosecond Pulses in Highly Germanium Doped Fiber 

      Tolstik, Nikolai; Klimentov, Dmitry; Dvoyrin, Vladislav; Sorokina, Irina T; Sorokin, Evgeni; Kalashnikov, Vladimir (Chapter, 2012)
      We demonstrate significant spectral broadening of femtosecond mid-IR pulses directly from the oscillator in a simple step-index single-mode highly Ge-doped fiber at only 150 pJ pulse energies in the spectral window around 2.38 µm.

    • Supercontinuum generation in Mid-IR using Chalcogenide and Germanate Nonlinear Fiber 

      Tolstik, Nikolai; Sorokin, Evgeni; Kalashnikov, Vladimir; Klimentov, Dmitry; Dvoyrin, Vladislav; Sorokina, Irina T (Journal article; Peer reviewed, 2013)
      We demonstrate mid-infrared (mid-IR) supercontinuum generation with bandwidth from 2 to 2.8 μm at 20 dB below the peak in nonlinear step-index chalcogenide fiber using femtosecond mid-IR pulses directly from the oscillator. ...

    • Vacuum Polarization Instead of “Dark Matter” in a Galaxy 

      Cherkas, Sergey L.; Kalashnikov, Vladimir (Journal article; Peer reviewed, 2022)
      We considered a vacuum polarization inside a galaxy in the eikonal approximation and found that two possible types of polarization exist. The first type is described by the equation of state p=ρ/3, similar to radiation. ...

    • Æther as an Inevitable Consequence of Quantum Gravity 

      Cherkas, Sergey; Kalashnikov, Vladimir (Peer reviewed; Journal article, 2022)
      The fact that quantum gravity does not admit an invariant vacuum state has far-reaching consequences for all physics. It points out that space could not be empty, and we return to the notion of an æther. Such a concept ...