Sökning: "Noise-immune cavity-enhanced optical heterodyne molecular spectrometry NICE-OHMS"

Hittade 5 avhandlingar innehållade orden Noise-immune cavity-enhanced optical heterodyne molecular spectrometry NICE-OHMS.

1. 1. 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

3. 2. Cavity enhanced optical sensing

   Författare :Isak Silander; Ove Axner; Aleksandra Foltynowicz; Jong Chow; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Optical resonators; Fiber Laser; Parametric oscillators; Optical frequency comb; Infrared; Spectroscopy heterodyne; Spectroscopy molecular; Absorption; Dispersion; Lineshapes; Optical standards and testing; Refractivety measurements;

   Sammanfattning : An optical cavity comprises a set of mirrors between which light can be reflected a number of times. The selectivity and stability of optical cavities make them extremely useful as frequency references or discri­mi­nators. LÄS MER

4. 3. Mid- and near-infrared NICE-OHMS : techniques for ultra-sensitive detection of molecules in gas phase

   Författare :Thomas Hausmaninger; Ove Axner; Kyle Crabtree; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spectrometry; NICE-OHMS; trace gas detection; acetylene; methane; isotopologues; near-infrared; mid-infrared; shot-noise; optical parametric oscillator; teknisk fysik med inriktningen mikrosystemteknik; engineering science with specialization in microsystems technology;

   Sammanfattning : Noise-immune cavity-enhanced optical heterodyne molecular spectrometry (NICE-OHMS) is a technique for ultra-sensitive detection of molecular absorption and dispersion. For highest performance, the technique combines cavity enhancement (CE) with frequency modulation (FM); while the former increases the effective interaction length between the light and the analyte by several orders of magnitudes, the latter removes the in-coupling of 1/f noise and makes the signals background free. LÄS MER

5. 4. Dicke narrowing and speed-dependent effects in dispersion signals : Influence on assessment of concentration and spectral parameters by noise-immune cavity-enhanced optical heterodyne molecular spectrometry

   Författare :Junyang Wang; Ove Axner; Livio Gianfrani; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Dicke narrowing; Speed-dependent effects; Dispersion signals; Noise-immune cavity-enhanced optical heterodyne molecular spectrometry NICE-OHMS ; accuracy;

   Sammanfattning : Laser spectroscopic techniques have, during the last decades, demonstrated an extraordinary capability for sensitive detection of molecular constituents in gas phase. Since spectra from such techniques constitute unique and characteristic signatures for each type of species, these techniques enable investigations of molecular structures as well as detection of the presence of species in a gas mixture. LÄS MER

7. 5. 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