Now showing items 1-13 of 13

    • 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 ...
    • 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 ...
    • 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 ...
    • 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 ...
    • 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 ...