Stimulated Raman scattering in compressed gases by short laser pulses
| Autor: | S. Hogiu, Valentin A. Orlovich, Wolfgang Werncke, A. I. Vodchits |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Dye laser
Hydrogen Chemistry Analytical chemistry Physics::Optics chemistry.chemical_element Laser Methane law.invention symbols.namesake chemistry.chemical_compound law Femtosecond symbols Physics::Atomic Physics Coherent anti-Stokes Raman spectroscopy Physics::Chemical Physics Raman spectroscopy Raman scattering |
| Zdroj: | Laser Optics 2000: Ultrafast Optics and Superstrong Laser Fields. |
| ISSN: | 0277-786X |
| DOI: | 10.1117/12.418810 |
| Popis: | Stimulated Raman scattering (SRS) excited by picosecond pulses (3.5 - 4 ps) of a synchronously pumped dye laser has been studied in compressed methane, hydrogen and their mixture. Physical energetic SRS-efficiencies (corrected for the linear losses of the optical elements) up to about 55 - 60% and 35 - 37% for the generation of the first vibrational Stokes radiation were reached in methane at a pressure of 60 bar and at excitation wavelengths near 600 nm and 740 nm, respectively. SRS-efficiencies versus pump pulse energy, pressure of gas and temporal duration of laser pulses were studied at 600 nm in methane. A very rich spectrum of Raman lines (including some vibrational, vibrational-rotational and combination Raman lines) was observed in the mixture of methane (35 bar) and hydrogen (25 bar). The energy efficiency of SRS-conversion to the 1-st rotational Stokes Raman line of hydrogen reached about 20% in the mixture. In contrast, the 1-st vibrational Stokes components of hydrogen and methane were substantially suppressed in this mixture. Our measurements demonstrate that methane is one of the most suitable Raman media for obtaining effective SRS-generation especially at pico- and femtosecond excitation because of its suitable parameters controlling the SRS-process and that the mixtures of compressed gases are rather promising Raman media for extending the tuning range of pico- and femtosecond laser systems and for optimizing the efficiencies of SRS-conversion to the different Raman components. |
| Databáze: | OpenAIRE |
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