Now showing items 1-12 of 70

    • 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 ...
    • Regularization of broad-area lasers by non-Hermitian potentials 

      Botey Cumella, Muriel; Ahmed, Waqas Waseem; Medina, Judith; Herrero Simon, Ramon; Wu, Ying; Staliunas, Kestutis (2019)
      Conference report
      Open Access
      It was recently shown that arbitrary non-Hermitian optical potentials based on local Parity-Time (PT-) symmetry may control the flow of light, due to the asymmetric mode coupling. We propose periodic non-Hermitian potentials ...
    • Methodology for lighting optimization applied to photocatalytic reactors 

      Tapia Tlatelpa, Tecilli; Trull Silvestre, José Francisco; Sala Caselles, Vicenç; Romeral Martínez, José Luis (Institute of Electrical and Electronics Engineers (IEEE), 2019)
      Conference lecture
      Open Access
      Replacement of conventional UV-lamps used in photocatalytic reactors by UV-LED sources with lower energy consumption and larger versatility has been proposed recently; However, the implementation of these types of sources ...
    • Surface and bulk harmonic generation in the opaque region of GaAs 

      Rodríguez Suñé, Laura; Trull Silvestre, José Francisco; Scalora, Michael; Cojocaru, Crina (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2019)
      Conference lecture
      Restricted access - publisher's policy
      We demonstrate second and third harmonic generation from a GaAs substrate, well-bellow the absorption edge, in both transmission and reflection geometries. The pump is tuned at 1064 nm, in the transparency range, while the ...
    • Brightness enhancement in Non-Hermintian VCSELs 

      Waseem Ahmed, Waqas; Herrero Simon, Ramon; Botey Cumella, Muriel; Staliunas, Kestutis (Optical Society of American (OSA), 2019)
      Conference report
      Restricted access - publisher's policy
      Vertical Cavity Surface Emitting lasers (VCSELs) are compact and efficient light sources useful for a variety of applications. However, due to lack of a transverse mode control mechanism, such lasers suffer from poor spatial ...
    • Non-Hermitian broad aperture semiconductor lasers based on PT-symmetry 

      Botey Cumella, Muriel; Waseem Ahmed, Waqas; Medina Pardell, Judith; Herrero Simon, Ramon; Staliunas, Kestutis (2019)
      Conference report
      Open Access
      In this paper we propose a novel configuration to regularize the complex spatiotemporal dynamics of broad area lasers into bright light beam. It has recently been shown that arbitrary non-Hermitian optical potentials based ...
    • Meta-mirrors with transverse invariance for beam shaping 

      Cheng, Yu-Chieh; Wang, Pei-Yu; Herrero Simon, Ramon; Botey Cumella, Muriel; Staliunas, Kestutis (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2019)
      Conference report
      Restricted access - publisher's policy
      The paper demonstrates spatial filtering in reflection based on meta-mirrors, composed of periodic subwavelength gratings. The periodic modulation of the refraction index on the sub-micron scale exhibits optical beam shaping ...
    • Non-Hermitian Light Management Based on Local Hilbert Transform 

      Staliunas, Kestutis; Waseem Ahmed, Waqas; Botey Cumella, Muriel; Herrero Simon, Ramon (Institute of Electrical and Electronics Engineers (IEEE), 2019)
      Conference report
      Restricted access - publisher's policy
      Light patterns; Metamaterials; Non-Hermitian optics; Microlasers
    • Phase locked harmonic generation in the opaque region of GaAs 

      Cojocaru, Crina; Rodríguez Suñé, Laura; Escalora, M.; Trull Silvestre, José Francisco (Institute of Electrical and Electronics Engineers (IEEE), 2019)
      Conference report
      Open Access
      We demonstrate second and third harmonic generation from a GaAs substrate, well-below the absorption edge, in both transmission and reflection geometries. The pump is tuned at 1064 nm, in the transparency range, while the ...
    • Structured Meta-Mirrors for Beam Spatial Filtering 

      Herrero Simon, Ramon; Wang, Pey-Yu; Botey Cumella, Muriel; Cheng, Yu-Chieh; Staliunas, Kestutis (Institute of Electrical and Electronics Engineers (IEEE), 2019)
      Conference report
      Open Access
      The work presents optical spatial filtering in reflection based on translationally invariant meta-mirrors. The meta-structure is generated by a thin grating presenting a transverse modulation of the refraction index on the ...
    • Characterization of speckle patterns generated by a semiconductor laser with optical feedback for speckle reduction in retinal imaging instruments 

      Halpaap, Donatus; Tiana Alsina, Jordi; Vilaseca Ricart, Meritxell; Masoller Alonso, Cristina (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2019)
      Conference lecture
      Restricted access - publisher's policy
      We study experimentally the operating conditions of a semiconductor laser diode subjected to different amounts of optical feedback in order to find a stable and cost-efficient solution for speckle reduction in double-pass ...
    • Stabilization of Broad Area Semiconductor Laser Sources 

      Medina Pardell, Judith; Ahmed, W. W.; Kumar, Shubham; Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis (Institute of Electrical and Electronics Engineers (IEEE), 2018)
      Conference report
      Open Access
      We numerically proof the stabilization of broad area semiconductor laser sources by introducing simultaneous in-phase two-dimensional modulations on the refractive index and on the pump (gain). We also examine the interplay ...