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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Studies in the stimulated emission of light

Deech, J. S. January 1968 (has links)
No description available.
22

A giant pulse ruby laser : construction and techniques of operation

Churchland, Mark T. January 1967 (has links)
A giant pulse ruby laser was constructed using a 6" long by ½" diameter ruby crystal. Techniques are discussed for controlling the temporal and spectral distribution of the laser output. A "Q" spoiling dye cell (cryptocyanine in methanol) was used to produce output pulses of 150 megawatts. "Mode locking" modulation of the output was also observed using the above dye cell. Using multiple surface front mirrors and apertures (3 to 5 mm. in diameter) the spectral line width of the output was reduced to .05 A. / Science, Faculty of / Physics and Astronomy, Department of / Graduate
23

Design of a submillimeter gas laser

Sahay, Vishnu January 1967 (has links)
A gas laser has been designed to 01lase over the entire far infra-red spectrum. This thesis discusses the theoretical and practical considerations that are involved in such a design. The three aspects of design that are discussed are the laser cavity, the excitation mechanism, and the detection apparatus. Every effort is made throughout to keep the system as simple as possible. Water vapor is used in the laser as a test gas, since it is known to have transitions in the far infra-red region. It was found to lase in several lines most of which have been identified with lines discovered by other workers. Two lines, however, appear to be new: 133.65μ, and 145.75μ with a possible error of ±.65μ. Characteristic variations of output power with pressure and current density have been obtained for the laser using water vapor. Attempts at obtaining laser action with acetone and alcohol proved unsuccessful. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate
24

Mode-locking de um laser de corante pulsado bombeado por lâmpada

Oliveira, Luiz Felipe Lorenzoni de 31 October 1994 (has links)
Orientador: Carlos Henrique de Brito Cruz / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-07-19T15:08:22Z (GMT). No. of bitstreams: 1 Oliveira_LuizFelipeLorenzonide_M.pdf: 2852272 bytes, checksum: d2b849e1203ded5e535eea8f5923eaff (MD5) Previous issue date: 1994 / Resumo: Neste trabalho descreve - se a teoria envolvida e os procedimentos experimentais que foram efetuados para a construção de um Lazer de Corante do tipo CPM bombeado por lâmpada flash com compensação da dispersão de velocidade de grupo e balanceamento da auto modulação de fase a partir de um Laser de Corante comercial marca Chromatix, modelo CMX - 4. Foram obtidos pulsos em 596,5 nm com durações temporais FWHM de 896 fs com 250 kW de potência de pico e com largura espectral de 1,5 nm / Abstract: In this work, we describe the construction of a CPM Dye Laser Flashlamp-Pumped with group velocity dispersion compensation and self phase modulation balancing, based on a comercial Dye Laser, Chromatrix, CMX-4 model. We obtain pulses at 596.5 nm with time duration FWHM of 896 fs with 250KW of peak power and spectral line width of 1.5nm / Mestrado / Física / Mestre em Física
25

The electronic instrumentation for atmospheric laser propagation studies

Brown, Clyde Manford 01 August 1968 (has links)
The use of laser radiation in atmospheric communication systems is revealing new forms of signal degradation not previously encountered with lower frequency transmitting sources. The coherence and directivity of the laser which is responsible for its increased signal capacity is degraded by the effect of atmospheric distortion. Random fluctuations in the index of refraction (turbulence), Rayleigh scattering, aerosol scattering and other atmospheric effects create fluctuations (boiling, breathing, dancing, attenuation, transit-time dispersion, etc.) within the beam cross section, which when received produce random fluctuations in the receiver output signal. The two systems which are described, are designed to investigate the effect of atmospheric distortions on the amplitude and phase (or transit time) of the laser beam. The Scintillation System was designed for real-time determination of amplitude scintillation statistics. The system will be incorporated into a multi-wavelength, multi-range experiment for comparison of theoretical and experimental meteorological and optical data. The system includes a laser transmitter, an atmospheric path over which the beam is allowed to diverge to a three-foot cross section, a pair of photomultipliers with variable spacing and small sampling apertures, an analog "scintillation computer," and a recording device. The scintillation computer is a real time, special purpose, analog computer designed to compute the variance and covariance of log amplitude, the probability distribution of log amplitude, and the frequency spectrum of the amplitude scintillation. The system permits the recording of these data as a function of transmitter and receiver aperture, and time. The Short Pulse Distortion System is designed to detect pulse distortion due to transit-time dispersion of the laser beam. The system includes a mode-locked laser (i.e., the optical short pulse generator), a large transmitting aperture (a Cassegrainian telescope), the atmospheric path, a wideband receiver, a sampling oscilloscope, the "Pulse Distortion Analyzer," and a high-quality tape recorder. The Pulse Distortion Analyzer is designed to compare the transmitted pulses to recorded reference pulses and to detect differential area due to time dispersion. The analyzer includes a novel, feed forward, automatic gain control circuit which utilizes a linear photo detector and an analog divider to smooth a 300Hz signal with a 100 microsecond response time. This is necessary to smooth out the signal amplitude fluctuations due to atmospheric turbulence effects. Both systems have been set up and tested on a one-mile path between the Oregon Graduate Center and Skyline Drive in Portland Oregon, using a 6328Å He-Ne Laser. The ultimate use of the scintillation computer will be in a multi-wave-length experiment conducted for the Office of Naval Research, and will utilize a uniform, meteorologically instrumented path for comparison with theoretical predictions. The Pulse Distortion System will be incorporated into a joint experiment with the Electro-optic Organization of Sylvania Electronic Systems, Inc., Mountain View, California, to be conducted over a seven-mile path.
26

Narrow-bandwidth operation and improved beam quality of a semiconductor broad area laser in an improved variable-length external cavity

Coons, Ryan William 28 November 2006 (has links)
No description available.
27

Transverse excited atmospheric pressure CO₂ laser

Deboo, James C. January 1971 (has links)
Thesis (M.S.)--University of Michigan, 1971.
28

Medical laser-induced thermotherapy models and applications /

Sturesson, Christian. January 1900 (has links)
Thesis (doctoral)--Department of Physics, Lund Institute of Technology, 1998. / "October 1998." Added t.p. with thesis statement inserted. Includes bibliographical references.
29

Medical laser-induced thermotherapy models and applications /

Sturesson, Christian. January 1900 (has links)
Thesis (doctoral)--Department of Physics, Lund Institute of Technology, 1998. / "October 1998." Added t.p. with thesis statement inserted. Includes bibliographical references.
30

THE CONSTRUCTION OF A PHOTODISSOCIATION ATOMIC IODINE LASER.

Soukup, Michael Scott. January 1983 (has links)
No description available.

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