Now showing items 1-16 of 16

    • Analysis of beam wander effects for a horizontal-path propagating Gaussian-beam wave: focused beam case 

      Recolons Martos, Jaume; Andrews, L.C.; Phillips, R.L. (SPIE-INT SOCIETY OPTICAL ENGINEERING, 2007-08-31)
      Article
      Open Access
      Failure of the first-order Rytov approximation to properly predict the scintillation index of a large-aperture focused beam, or an uplink collimated (or focused) beam, has been discussed in several recent publications, ...
    • Confocal flowmeter based on self-mixing interferometry for real-time velocity profiling of turbid liquids flowing in microcapillaries 

      Yáñez Alvarado, Carlos René; Azcona Guerrero, Francisco Javier; Royo Royo, Santiago (2019-08-19)
      Article
      Open Access
      We propose a new confocal device for flow profiling in microcapillaries. A viewfinder system is developed using a visible light microscope, allowing focusing with high precision an 830 nm Fabry-Perot laser diode on a ...
    • Cost-effective microfabrication of sub-micron-depth channels by femto-laser anti-stiction texturing 

      Karimi, Shadi; Mehrdel, Pouya; Casals Terré, Jasmina; Farré Lladós, Josep (2020-02-26)
      Article
      Open Access
      Micro Electro Mechanical Systems (MEMS) and microfluidic devices have found numerous applications in the industrial sector. However, they require a fast, cost-effective and reliable manufacturing process in order to compete ...
    • Demonstration of a highly-sensitive tunable beam displacer with no use of beam deflection based on the concept of weak value amplification 

      Salazar-Serrano, Luis José; Guzmán, David A.; Valencia, Alejandra; Pérez Torres, Juan (OSA, 2015-04-20)
      Article
      Open Access
      We report the implementation of a highly sensitive tunable beam displacer based on the concept of weak value amplification, that allows to displace the centroid of a Gaussian beam a distance much smaller than its beam width ...
    • Flat focusing mirrors 

      Staliunas, Kestutis; Cheng, Yu-Chiech; Kicas, Simonas; Trull Silvestre, José Francisco; Cojocaru, Crina; Peckus, Martynas; Vilaseca Alavedra, Ramon; Drazdys, Ramutis (Institute of Electrical and Electronics Engineers (IEEE), 2015)
      Conference report
      Restricted access - publisher's policy
      We present the flat focusing mirror - the dielectric mirrors capable to focus and image the narrow beams in reflections. The mirrors are flat, and transversally invariant, i.e. have no optical axis. We consider two different ...
    • Influence of laser beam power and scanning speed on the macrostructural characteristics of AISI 316L and AISI 431 stainless steel depositions produced by laser cladding process 

      Figueredo, Erike; Apolinario, Luis; Santos, Mayara; Silva, Ana; Ávila Díaz, Julián Arnaldo; Lima, Milton; Santos Felipe, Tiago (2021-04-05)
      Article
      Open Access
      In the laser cladding process, control of the process parameters and knowledge of the characteristics of the materials used are essential for obtaining depositions with excellent metallurgical union, satisfactory dilution ...
    • Laser wire emittance measurement line at CLIC 

      Garcia, Hector; Koubychine Merkulov, Youri Alexandrovich; Blair, Grahame; Aumeyr, T; Schulte, Daniel; Shvedunov, V.I. (2012)
      Conference lecture
      Open Access
      A precise measurement of the transverse beam size and beam emittances upstream of the final focus is essential for ensuring the full luminosity at future linear colliders. A scheme for the emittance measurements at the ...
    • Light dynamics in glass-vanadium dioxide nanocomposite waveguides with thermal nonlinearity 

      Kartashov, Yaroslav; Vysloukh, Victor A. (2009-04)
      Article
      Open Access
      We address the propagation of laser beams in SiO2–VO2 nanocomposite waveguides with thermo-optical nonlinearity. We show that the large modifications of the absorption coefficient as well as notable changes of the ...
    • Optical path length measurement of spherical dielectric shells with axicon-generated Bessel beams; applications to corneal sensing 

      Baggio, Mariangela; Tamminen, Aleksi; Zarrinkhat, Faezeh; Nefedova, Irina; Aspelin, Arthur; Ala-Laurinaho, Juha; Wallace, Vincent; Brown, Elliott; Taylor, Zachary (2021)
      Conference lecture
      Open Access
      A custom aspheric axicon lens for corneal water content sensing, operating from 220 to 330 GHz, was evaluated with spherical, dielectric shell targets. The lens consisted of a hyperbolic back surface and conical front ...
    • Preparation of engineered two-photon entangled states for multidimensional quantum information 

      Pérez Torres, Juan; Deyanova, Y; Torner Sabata, Lluís; Molina Terriza, Gabriel (2003-05)
      Article
      Restricted access - publisher's policy
      We put forward an experimentally feasible technique to generate engineered entangled states in d-dimensional Hilbert spaces in parametric down-conversion of photons. The scheme is based on the orbital angular momentum of ...
    • Random number generation by coherent detection of quantum phase noise 

      Álvarez, Juan Rafael; Sarmiento Hernández, Samael; Lázaro Villa, José Antonio; Gené Bernaus, Joan M.; Pérez Torres, Juan (2020-02-17)
      Article
      Open Access
      In 2010 Qi et al. [Opt. Lett. 35(3), 312 (2010)] demonstrated a random number generator based on the drift of the phase of a laser due to spontaneous emission, The out-of-the-lab implementation of this scheme presents two ...
    • Schädigungsparameter für Laserstrahlschweißverbindungen unter zyklischen, mehraxialen Belastungen 

      Barrabino Clemente, Marta (Universitat Politècnica de Catalunya / Technische Universität Darmstadt, 2011)
      Master thesis (pre-Bologna period)
      Restricted access - author's decision
      In der Automobil- und Luftfahrtbranche werden Laserstrahlschweißverbindungen häufig benutzt. Die Technologie erlaubt eine effektive Verbindung dünnwandiger Leichtbaukonstruktionen. Bei schneller Fertigung ermöglicht sie ...
    • Study of femtosecond laser beam focusing in a direct-write system 

      Van Eeckhout Alsinet, Albert (Universitat Politècnica de Catalunya, 2016-07-22)
      Master thesis
      Open Access
      Direct-write techniques appear as a versatile option in rapid-prototyping applications because they can directly transfer a custom pattern from a digital file. Lasers are a distinguished tool which allow to perform non-contact ...
    • Study of heat sources interacting in integrated circuits by laser mirage effect 

      Perpiñà Gilabet, Xavier; Jordà, Xavier; Vellvehi, Miquel; Altet Sanahujes, Josep (2014-08-25)
      Article
      Restricted access - publisher's policy
      This work exploits the mirage effect to analyze multiple heat sources thermally interacting in an integrated circuit (IC) by means of a probe IR laser beam, which strikes on the die lateral walls and passes through the die ...
    • 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 ...
    • Temporal analysis of laser beam propagation in the atmosphere using computer-generated long phase screens 

      Dios Otín, Víctor Federico; Recolons Martos, Jaume; Rodríguez Gómez, Alejandro Antonio; Batet Torrell, Óscar (2008-02-04)
      Article
      Open Access
      Temporal analysis of the irradiance at the detector plane is intended as the first step in the study of the mean fade time in a free optical communication system. In the present work this analysis has been performed for a ...