Spectroscopic results with laser induced breakdown spectroscopy (LIBS) in liquids have shown a si... more Spectroscopic results with laser induced breakdown spectroscopy (LIBS) in liquids have shown a signal improvement using double pulse experiments compared to single pulse measurements. A setup of two Q-switched Nd:YAG lasers in an orthogonal arrangement have led to bright illuminated plasma inside cavitation bubbles. A Nd:YAG laser pulse focussed by a lens (6 ns@532 nm, 2.9*1019 W/m2) into the center of a water filled cuvette gives rise to a cavitation bubble. A second tightly focused Nd:YAG laser pulse (5 ns@1064 nm, 3.1*1019 W/m2 ) induces a plasma at approximately 70 mus delay within the cavitation bubble. These absolutely reliable processes allow to capture image sequences of plasma filled cavitation bubbles with an ultrafast camera. The optical emission is guided via a quartz fibre to a Czerny-Turner spectrograph and recorded by an intensified CCD camera. A delay time of more than 1.7 mus between plasma ignition and spectroscopic data taking is necessary to avoid inverse bremsstrahlung and residual lines arising from bright plasma emission. Characteristic spectral line intensities of manganese (Mn) and Palladium (Pd) are recorded and correlated with an internal calibration standard using strontium (Sr) and chromium (Cr) respectively. The LOD of manganese is 0.3 mg/L.
Long-term surveillance of coastal zones like the German Bight with airborne laser fluorosensors h... more Long-term surveillance of coastal zones like the German Bight with airborne laser fluorosensors have shown the capability of active remote sensing to investigate various oceanic parameters, such as dissolved organic matter (gelbstoff) or chlorophyll in algae. Recently the feasibility of a spaceborne laser fluorosensor for large-scale monitoring of water-column parameters has met increasing interest. Complementary to passive remote sensing instruments,
... Fig. 2. Effect of dispersion for a laser beam starting at 300 km altitude at variable nadir a... more ... Fig. 2. Effect of dispersion for a laser beam starting at 300 km altitude at variable nadir angles Θlaser measured via the deviation distance for two wavelengths. Fig. ... 10. McCartney, EJ (1976), Optics of the Atmosphere - Scattering by Molecules and Particles, Wiley & Sons. 11. ...
Depth profiles of fluorescence at several excitation and emission wavelengths were measured along... more Depth profiles of fluorescence at several excitation and emission wavelengths were measured along with CTD data during the cruise So119 of RV Sonne in the Arabian Sea from 12 May to 10 June 1997. In addition to chlorophyll fluorescence from phytoplankton in the near-surface layer, the profiles in the oxygen minimum region well below the euphotic zone show enhanced red
... Contrast enhanced imaging in the sea: Application of the optical transfer function for image ... more ... Contrast enhanced imaging in the sea: Application of the optical transfer function for image reconstruction ... If the imaging system is considered to be linear and shift-invariant, the intensity distribution of ... For this method it is necessary to realise a statistical model which includes all ...
Spectroscopic results with laser induced breakdown spectroscopy (LIBS) in liquids have shown a si... more Spectroscopic results with laser induced breakdown spectroscopy (LIBS) in liquids have shown a signal improvement using double pulse experiments compared to single pulse measurements. A setup of two Q-switched Nd:YAG lasers in an orthogonal arrangement have led to bright illuminated plasma inside cavitation bubbles. A Nd:YAG laser pulse focussed by a lens (6 ns@532 nm, 2.9*1019 W/m2) into the center of a water filled cuvette gives rise to a cavitation bubble. A second tightly focused Nd:YAG laser pulse (5 ns@1064 nm, 3.1*1019 W/m2 ) induces a plasma at approximately 70 mus delay within the cavitation bubble. These absolutely reliable processes allow to capture image sequences of plasma filled cavitation bubbles with an ultrafast camera. The optical emission is guided via a quartz fibre to a Czerny-Turner spectrograph and recorded by an intensified CCD camera. A delay time of more than 1.7 mus between plasma ignition and spectroscopic data taking is necessary to avoid inverse bremsstrahlung and residual lines arising from bright plasma emission. Characteristic spectral line intensities of manganese (Mn) and Palladium (Pd) are recorded and correlated with an internal calibration standard using strontium (Sr) and chromium (Cr) respectively. The LOD of manganese is 0.3 mg/L.
Long-term surveillance of coastal zones like the German Bight with airborne laser fluorosensors h... more Long-term surveillance of coastal zones like the German Bight with airborne laser fluorosensors have shown the capability of active remote sensing to investigate various oceanic parameters, such as dissolved organic matter (gelbstoff) or chlorophyll in algae. Recently the feasibility of a spaceborne laser fluorosensor for large-scale monitoring of water-column parameters has met increasing interest. Complementary to passive remote sensing instruments,
... Fig. 2. Effect of dispersion for a laser beam starting at 300 km altitude at variable nadir a... more ... Fig. 2. Effect of dispersion for a laser beam starting at 300 km altitude at variable nadir angles Θlaser measured via the deviation distance for two wavelengths. Fig. ... 10. McCartney, EJ (1976), Optics of the Atmosphere - Scattering by Molecules and Particles, Wiley & Sons. 11. ...
Depth profiles of fluorescence at several excitation and emission wavelengths were measured along... more Depth profiles of fluorescence at several excitation and emission wavelengths were measured along with CTD data during the cruise So119 of RV Sonne in the Arabian Sea from 12 May to 10 June 1997. In addition to chlorophyll fluorescence from phytoplankton in the near-surface layer, the profiles in the oxygen minimum region well below the euphotic zone show enhanced red
... Contrast enhanced imaging in the sea: Application of the optical transfer function for image ... more ... Contrast enhanced imaging in the sea: Application of the optical transfer function for image reconstruction ... If the imaging system is considered to be linear and shift-invariant, the intensity distribution of ... For this method it is necessary to realise a statistical model which includes all ...
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