Browsing by Author "Gailevicius, Darius"

Now showing items 1-20 of 21

    • Angular filtering by Bragg photonic microstructures fabricated by physical vapour deposition 

      Grineviciute, Lina; Babayigit, Ceren; Gailevicius, Darius; Bor, Emre; Turduev, Mirbek; Purlys, Vytautas; Tolenis, Tomas; Kurt, Hamza; Staliunas, Kestutis (2019-07-01)
      Article
      Open Access
      We propose and experimentally demonstrate spatial filtering by photonic crystals in a Bragg configuration. Compared to the Laue configuration, where spatial filtering was already demonstrated before, the Bragg configuration ...

    • Dynamic higher-order Bessel-Gauss beam interference generation of rotating beams 

      Kontenis, Gabrielius; Gailevicius, Darius; Jiménez, Noé; Staliunas, Kestutis (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2022)
      Conference report
      Restricted access - publisher's policy
      One of the key trends in laser material processing is the usage of structured laser beams. One such example is the Bessel beam with an elongated focal area and self-healing properties. Higher-order Bessel beams can be ...

    • Extremely narrow, sharp-peaked resonances at the edge of the continuum 

      Lukošiunas, Ignas; Grineviciute, Lina; Nikitina, Julianija; Gailevicius, Darius; Staliunas, Kestutis (2022-11-03)
      Research report
      Open Access
      We report a critical narrowing of resonances of a driven potential well, when their eigenfrequencies approach the edge of the continuum. The resonances also obtain unusual sharp-peak shapes at the continuum boundary. The ...

    • Flat lensing in the visible frequency range by woodpile photonic crystals 

      Maigyte, Lina; Purlys, Vytautas; Trull Silvestre, José Francisco; Peckus, Martynas; Cojocaru, Crina; Gailevicius, Darius; Malinauskas, Mangirdas; Staliunas, Kestutis (2013-07-15)
      Article
      Open Access
      We experimentally demonstrate full two-dimensional focalization of light beams at visible frequencies by a three-dimensional woodpile photonic crystal. The focalization (the flat lensing) with focal distances of the order ...

    • Inverse designed photonic crystals for spatial filtering 

      Babayigit, Ceren; Grineviciute, Lina; Nikitina, Julianija; Melnikas, Simas; Gailevicius, Darius; Staliunas, Kestutis (American Institute of Physics (AIP), 2023-06-13)
      Article
      Restricted access - publisher's policy
      Zero incidence angle spatial filters of a compact design can be very useful, among others, for intracavity spatial filtering in high-power micro-lasers. Typically, micro-lasers, especially in high-power operation regimes, ...

    • Modes in microchip lasers 

      Plukys, Matas; Gaizauskas, Eugenijus; Gailevicius, Darius; Staliunas, Kestutis (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2022)
      Conference report
      Restricted access - publisher's policy
      The transverse modes in microchip lasers (MCL) appear different from the classical mode theory, as the resonator consists of a set of plane mirrors (similar to semiconductor edge-emitting lasers and VCSELs). Then the ...

    • Nanostructured multilayer coatings for spatial filtering 

      Grineviciute, Lina; Babayigit, Ceren; Gailevicius, Darius; Peckus, Martynas; Turduev, Mirbek; Tolenis, Tomas; Vengris, Mikas; Kurt, Hamza; Staliunas, Kestutis (2021-03-16)
      Article
      Open Access
      Spatial filtering is an important mechanism to improve the spatial quality of laser beams. Typically, a confocal arrangement of lenses with a diaphragm in the focal plane is used for intracavity spatial filtering. Such ...

    • Optical drills by dynamic high-order bessel beam mixing 

      Kontenis, Gabrielius; Gailevicius, Darius; Jiménez, Noé; Staliunas, Kestutis (American Physical Society (APS), 2022-03-25)
      Article
      Open Access
      One of the key trends in laser material processing is the usage of structured laser beams. Collimated and focused Gaussian beams are the most common tools; however, more exotic beams can be beneficial too. For instance, ...

    • Photonic Crystal Microchip Laser 

      Gailevicius, Darius; Koliadenko, Volodymyr; Purlys, Vytautas; Peckus, Martynas; Taranenko, Victor; Staliunas, Kestutis (Macmillan Publishers, 2016-09-29)
      Article
      Open Access
      The microchip lasers, being very compact and efficient sources of coherent light, suffer from one serious drawback: low spatial quality of the beam strongly reducing the brightness of emitted radiation. Attempts to improve ...

    • Photonic crystal spatial filtering in broad aperture diode laser 

      Gawali, Sandeep Babu; Gailevicius, Darius; Garre Werner, Guillermo; Purlys, Vytautas; Cojocaru, Crina; Trull Silvestre, José Francisco; Montiel Ponsoda, Joan; Staliunas, Kestutis (2019-10-02)
      Article
      Open Access
      Broad aperture semiconductor lasers usually suffer from low spatial quality of the emitted beams. Due to the highly compact character of such lasers, the use of conventional intracavity spatial filters is problematic. We ...

    • Photonic crystal spatial filters fabricated by femtosecond pulsed Bessel beam 

      Gailevicius, Darius; Purlys, Vytautas; Staliunas, Kestutis (2019-10-15)
      Article
      Open Access
      We propose and experimentally demonstrate femtosecond direct laser writing with Bessel beams for the fabrication of photonic crystals with spatial filtering functionality. Such filters are mechanically stable, of small (of ...

    • Photonic crystals for suppression of filamentation 

      Aleksandravicius, Edvinas; Gailevicius, Darius; Dubietis, Audrius; Staliunas, Kestutis (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2022)
      Conference report
      Restricted access - publisher's policy
      In this work we show the prospect of using periodic refractive index modulation – photonic crystals – to control the spatial dispersion curvature in a way that could potentially counteract the Kerr effect, thus suppressing ...

    • Spatial filter realized by dielectrice waveguides 

      Lukošiunas, Ignas; Gailevicius, Darius; Staliunas, Kestutis (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2022)
      Conference report
      Restricted access - publisher's policy
      In this work, we introduce a spatial filtering mechanism that can be effectively utilized by photonic crystals. The phenomenon utterly expressed here is Rayleigh-Wood’s anomaly. Such a mechanism is realized and optimized ...

    • Spatial filtering by axisymmetric photonic crystals 

      Staliunas, Kestutis; Gailevicius, Darius; Purlys, Vytautas; Maigyte, Lina; Peckus, Martynas (Institute of Electrical and Electronics Engineers (IEEE), 2016)
      Conference report
      Restricted access - publisher's policy
      Photonic crystals due to their angular bandgaps and quasi-bandgaps can provide spatial (angular) filtering of light. Two-dimensional photonic crystals (photonic structures modulated along the longitudinal and along one ...

    • Spatial filtering in broad area semiconductor laser using photonic crystal 

      Gawali, Sandeep Babu; Gailevicius, Darius; Purlys, Vytautas; Trull Silvestre, José Francisco; Cojocaru, Crina; Staliunas, Kestutis (2020)
      Conference lecture
      Restricted access - publisher's policy
      In high power regimes, broad area semiconductor lasers usually suffer from poor beam quality due to their asymmetric beam divergence, large beam quality factor (M2) and from the absence of any intrinsic filtering mechanism ...

    • Spatial Filters on Demand Based on Aperiodic Photonic Crystals 

      Gailevicius, Darius; Purlys, Vytautas; Peckus, Martynas; Gadonas, Roaldas; Staliunas, Kestutis (2017-08-01)
      Article
      Open Access
      Photonic Crystal spatial filters, apart from stand-alone spatial filtering function, can also suppress multi-transverse-mode operation in laser resonators. Here it is shown that such photonic crystals can be designed by ...

    • Super-collimation by axisymmetric diffractive metamirror 

      Gailevicius, Darius; Grineviciute, Lina; Peckus, Martynas; Staliunas, Kestutis; Taranenko, Victor (2021-08-05)
      Article
      Restricted access - publisher's policy
      We propose and demonstrate experimentally super-collimation of light beams by an axisymmetric diffractive metamirror—an axisymmetric concentric dielectric ring structure positioned in front of a mirror at a distance of ...

    • Super-collimation by axisymmetric photonic crystals 

      Purlys, Vytautas; Maigyte, Lina; Gailevicius, Darius; Peckus, Martynas; Gadonas, Roaldas; Staliunas, Kestutis (2014-06-02)
      Article
      Open Access
      We propose and experimentally show the mechanism of beam super-collimation by axisymmetric photonic crystals, specifically by periodic (in propagation direction) structure of layers of concentric rings. The physical mechanism ...

    • Supercollimation of light beams by axisymmetric aperiodic photonic structures 

      Gailevicius, Darius; Aleksandravicius, Edvinas; Purlys, Vytautas; Staliunas, Kestutis (2021-12-14)
      Article
      Restricted access - publisher's policy
      Efficient beam supercollimation is proposed and shown experimentally by axisymmetric aperiodic photonic structures. The structure consists of equidistant layers of concentric refraction index rings, with the transverse ...

    • Tilted black-Si: ~0.45 form-birefringence from sub-wavelength needles 

      Gailevicius, Darius; Suzuki, T.; Staliunas, Kestutis (2020-05-25)
      Article
      Open Access
      The self-organised conical needles produced by plasma etching of silicon (Si), known as black silicon (b-Si), create a form-birefringent surface texture when etching of Si orientated at angles of ¿i¿<¿50¿-¿70° (angle between ...