Sökning: "Laser spectrum"

Visar resultat 1 - 5 av 118 avhandlingar innehållade orden Laser spectrum.

1. 1. Novel Technologies for Mode-Locking of Solid-State Lasers

   Författare :Niels Meiser; Valdas Pasiskevicius; Steinmeyer Günter; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; laser; mode-locked laser; pulsed laser; quantum dot; carbon nanotube; nonlinear optics; saturable absorber; Kerr-lens mode-locking; ultra-fast laser; picosecond laser; pulsed laser; semiconductor saturable absorber;

   Sammanfattning : The subject of this thesis is the investigation of novel technologies for mode-locking of diode-pumped, solid-state lasers. Novel saturable absorbers are used: quantum dots (QDs) and carbon nanotubes (CNTs), which both are low-dimensional nano-formations. In addition, mode-locking by cascaded nonlinearities is explored. LÄS MER

3. 2. Spectral analysis in laser powder bed fusion

   Författare :Benedikt Brandau; Frank Brückner; Alexander Kaplan; Dan Roth-Fagaraseanu; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spectral monitoring; Laser powder bed fusion; Laser optics; Absorbance; Produktionsutveckling; Manufacturing Systems Engineering;

   Sammanfattning : This thesis is about the investigation of the spectral interaction of electromagnetic radiation with metal powders. For this purpose, spectral data of powders for laser powder bed fusion processes are investigated in three papers using different techniques. LÄS MER

4. 3. Continuous-filtering Vernier spectroscopy

   Författare :Chuang Lu; Aleksandra Foltynowicz; Ove Axner; Wei Ren; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spectroscopy; spectrometer; laser; optical frequency comb; optical cavity; NIR; MIR; flame; robust; time resolution; spectrum; fysik; Physics;

   Sammanfattning : Continuous-filtering Vernier spectroscopy (CF-VS) is a laser-based detection technique that combines the broad spectral coverage of an optical frequency comb (OFC) with the enhanced interaction length provided by an optical cavity. The resonances of the cavity filter the OFC to a small group of comb modes that probe the transitions of the species present in the cavity. LÄS MER

5. 4. Nonlinear optical techniques for ultrafast laser diagnostics : Development of femtosecond LIF, LIGS, CARS and backward lasing

   Författare :Maria Ruchkina; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; laser diagnostics; femtosecond laser; nonlinear interactions; ultrafast spectroscopy; multi-photon excitation; laser-induced fluorescence; rotational coherent anti-Stokes Raman spectroscopy; laser-induced grating spectroscopy; lasing; backward lasing technique; Fysicumarkivet A:2021:Ruchkina;

   Sammanfattning : The thesis work concerns development and application of four versatile nonlinear optical techniques, based on exploiting ultrashort laser pulses, for diagnostic purposes in gases and flames. The four techniques, all laser-based, are two-photon laser-induced fluorescence (TPLIF), hybrid femtosecond/nanosecond (fs/ns) rotational coherent anti-Stokes Raman scattering (fs/ns RCARS), fs-laser-induced grating spectroscopy (fs-LIGS), and backward lasing. LÄS MER

7. 5. Laser spectroscopic analysis of atmospheric gases in scattering media

   Författare :Mikael Sjöholm; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fjärranalys; Remote sensing; Laser spectroscop; Scattering of light; Diode lasers; acoustics; optics; Electromagnetism; optik; akustik; Elektromagnetism; Optical absorption; Nondestructive testing: optical; Interdisciplinary applications of physics; Laser technology; Atom- och molekylärfysik; Atomic and molecular physics; LIDAR remote sensing; Laserteknik;

   Sammanfattning : Laser spectroscopic techniques for gas analysis under various influences of light scattering are explored in a wide spectral range from the ultraviolet to the infrared. The techniques rely on spectrally narrow-band light sources that are used in differential optical absorption measurements. LÄS MER