Sökning: "laser frequency stabilization"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden laser frequency stabilization.

1. 1. Laser-based absorption spectrometry : development of NICE-OHMS towards ultra-sensitive trace species detection

   Författare :Florian Schmidt; Ove Axner; Livio Gianfrani; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; absorption spectrometry; trace species detection; fiber laser; modulation; cavity-enhanced spectroscopy; optical saturation; laser frequency stabilization; free-spectral-range; Physics; Fysik;

   Sammanfattning : Laser-based absorption spectroscopy (AS) is a powerful technique for qualitative and quantitative studies of atoms and molecules. An important field of use of AS is the detection of species in trace concentrations, which has applications not only in physics and chemistry but also in biology and medicine, encompassing environmental monitoring, regulation of industrial processes and breath analysis. LÄS MER

3. 2. Fiber-laser-based noise-immune cavity-enhanced optical heterodyne molecular spectrometry

   Författare :Aleksandra Foltynowicz; Ove Axner; Weidong Chen; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; absorption spectrometry; frequency modulation; cavity enhancement; NICE-OHMS; Laser frequency stabilization; fiber laser; Fabry-Perot cavities; sub-Doppler spectroscopy; trace gas detection; Physics; Fysik; Molecular physics; Molekylfysik; fysik; Physics;

   Sammanfattning : Noise-immune cavity-enhanced optical heterodyne molecular spectro-metry (NICE-OHMS) is one of the most sensitive laser-based absorption techniques. The high sensitivity of NICE-OHMS is obtained by a unique combination of cavity enhancement (for increased interaction length with a sample) with frequency modulation spectrometry (for reduction of noise). LÄS MER

4. 3. Quantum computing with naturally trapped sub-nanometre-spaced ions

   Författare :Lars Rippe; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Laserteknik; Laser technology; Atom- och molekylärfysik; Atomic and molecular physics; akustik; optik; Elektromagnetism; optics; acoustics; Electromagnetism; Fysik; Physics; entanglement; spectroscopy; rare-earth-metal-ion-doped crystals spectral hole-burning; inversion; excitation; laser stabilization; quantum computation; quantum gate;

   Sammanfattning : The main aim of this work, was to lay the foundations for the experimental realisation of a quantum mechanical controlled NOT gate in rare-earth-metal-ion-doped crystals. Small amounts of rare-earth elements, added during the growth of some inorganic crystals, will become substituted into the crystal lattice as trivalent ions. LÄS MER

5. 4. 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

7. 5. Radiative Properties of Rare Earth Elements - Free and Bound in Crystals

   Författare :Huailiang Xu; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Laser Spectroscopy; Upconversion; Lifetimes; Atomic and molecular physics; Atom- och molekylärfysik; Laser technology; Laserteknik; Rare earth Elements; Fysicumarkivet A:2004:Xu;

   Sammanfattning : This thesis is devoted to fundamental aspects, and to spectroscopic applications of radiative properties in free atoms and ions, as well as in ions doped into crystals. Using the time-resolved laser-induced fluorescence technique, measurements of radiative lifetimes for rare earth elements have been performed in neutral Pr, Nd, Tm, and in singly ionized Sm, Er, Nd, Tm, Yb, as well as in doubly ionized Tm and Tb ions. LÄS MER