Titanium: Sapphire Laser as an Excitation Source in Two-Photon Spectroscopy
| Autor: | Colin Seaton, Michael Armas, W. G. Fisher, E. A. Wachter |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Materials science
Dye laser business.industry 010401 analytical chemistry Far-infrared laser Ti:sapphire laser Physics::Optics Laser 01 natural sciences 0104 chemical sciences law.invention 010309 optics Optics Mode-locking law 0103 physical sciences Sapphire Optoelectronics Laser power scaling business Instrumentation Spectroscopy Tunable laser |
| Zdroj: | Applied Spectroscopy. 51:218-226 |
| ISSN: | 1943-3530 0003-7028 |
| DOI: | 10.1366/0003702971939910 |
| Popis: | The passively mode-locked titanium: sapphire laser provides new opportunities for acquiring two-photon spectral data in the near-infrared, a region not commonly accessible to synchronously pumped dye lasers. This source generates pulses with peak powers near 100 kW at average powers over 1 W and is capable of yielding two-photon signals roughly two orders of magnitude larger than is possible with synchronously pumped dye lasers. However, the multimode output of this laser exhibits significant temporal and spectral pulse profile variations as the laser wavelength is tuned. As a consequence, peak powers of the titanium:sapphire laser can vary independently from average power across the tuning range. This wavelength dependence, coupled with the quadratic dependence of the two-photon signal upon the instantaneous power of the laser, precludes simple average power correction of nonlinear spectral band shapes. Here, we investigate the key properties of the titanium:sapphire laser as an excitation source for two-photon spectroscopy. We also identify a chemical reference suitable for obtaining source-corrected excitation spectra in the near-infrared using a double-beam, ratiometric approach; this is based on a source-in-dependent two-photon excitation spectrum for the laser dye coumarin-480 that has been obtained with a single-frequency titanium:sapphire laser. From these data, correction factors are generated for correction of multimode source data. |
| Databáze: | OpenAIRE |
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