Modeling the Time-Dynamics of Miniature Passively $Q$-switched Lasers
Autor: | Esa Räikkönen, Matti Kaivola, Scott Buchter |
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Rok vydání: | 2009 |
Předmět: |
Materials science
Active laser medium business.industry Absorption cross section Physics::Optics chemistry.chemical_element Saturable absorption Rate equation Condensed Matter Physics Laser Q-switching Neodymium Atomic and Molecular Physics and Optics law.invention Cross section (physics) Optics chemistry law Electrical and Electronic Engineering Atomic physics business |
Zdroj: | IEEE Journal of Quantum Electronics. 45:1563-1570 |
ISSN: | 1558-1713 0018-9197 |
DOI: | 10.1109/jqe.2009.2022280 |
Popis: | The pulse-buildup in miniature passively Q-switched lasers occurs in a similar time-scale as the phonon-assisted thermalization of the laser manifolds. We study how the time-dynamics of the laser is affected by the thermalization and relaxation processes using a dimensionless geometrical rate equation model for a homogeneously broadened four-level gain medium. The pulse length is found to depend strongly on the thermalization rate when the ratio of the ground-state absorption cross section of the saturable absorber to the spectroscopic emission cross section of the laser transition is small (lsim 10). Numerically calculated design curves are shown for the 1064 nm transition in Nd:YAG, and guidelines are given for applying the model to other transitions. Experimental results are used for estimating the thermalization time constant of Nd:YAG for the 1 mum transition group and the ground-state absorption cross section of the Cr4+:YAG saturable absorber crystal. |
Databáze: | OpenAIRE |
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