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Published byDominick Wilcox Modified over 8 years ago
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Atomic and molecular spectroscopy with UV and Visible superbright LEDs Goran Pichler Ticijana Ban, Hrvoje Skenderović and Goran Pichler Institute of Physics, Bijenička cesta 46, P. O. Box 304, HR-10001 Zagreb, Croatia Our most recent absorption and emission experiments with heavy alkali vapor using superbright light emitting diodes from NICHIA, LUMILED and OSRAM will be presented. UV LEDs together with LEDs in the visible spectral region present invaluable narrow band continuum light source for very precise absorption measurements. We used all- sapphire cells in a usual absorption arrangement high resolution scanning monochromators. Beside self-broadened alkali resonance lines we investigated molecular bands and diffuse bands of alkali dimers similar to experiment in ref. (1). A number of applications, especially in dentistry will be also presented.
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Spectral change of blue LED with UV component at different repetition rate and different pulse width, at constant pulsed electric current of 90 mA.
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UV and violet light emitting diodes
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Absorption experiment in rubidium vapor with NICHIA UV-LED as a background source with a possibility to measure fluorescence induced by NICHIA violet laser at 420 nm.
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Transmission spectra at four different temperatures in the all-sapphire cell filled with cesium saturated vapor (T=291 oC), and superheated vapor (T= 424, 476, 535 oC). Absorption coefficient in the 380-480 nm spectral range at four different temperatures in the all-sapphire cell filled with cesium saturated vapor (T=291 oC), and superheated vapor (T= 424, 476, 535 oC).
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Violet LED continuum is ideal for absorption of a second potassium doublet
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Almost perfect match between blue LED and Camphorquinone absorption used for photoplymerization of composite materials in dentistry.
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