Dependence of laser-induced fluorescence on exciting-laser power: partial saturation and laser – plasma interaction
| Authors | |
|---|---|
| Year of publication | 2015 |
| Type | Article in Periodical |
| Magazine / Source | The European Physical Journal - Applied Physics |
| MU Faculty or unit | |
| Citation | |
| Web | http://www.epjap.org/articles/epjap/abs/2015/08/ap150022/ap150022.html |
| Doi | http://dx.doi.org/10.1051/epjap/2015150022 |
| Field | Plasma physics |
| Keywords | laser-induced fluorescence; least-squares fitting; partial saturation; lifetime |
| Description | In recent publications on laser-induced fluorescence (LIF), the measurements are usually constricted to the region of weak exciting-laser power – the so called linear LIF. In this work, a practical formula F(E_L) = (alpha) *E_L / (1+(beta)*E_L) describing the dependence of partially saturated fluorescence on the exciting-laser power is derived, together with practical implementation suggestions and comments on its limitations. In the conclusion, the practical formula is proposed with the limitation for validity (beta)*EL = 0.4, where (alpha)*EL is the hypothetical linear fluorescence without saturation effects, and a more general formula is derived, which is valid for higher values of (alpha)*EL as well. Extending the range of exciting laser power to the region of partial saturation enhances the signal-to-noise ratio. Such measurements in a surface dielectric barrier discharge further reveal discharge disruption by photoelectrons emitted from the dielectric surface. Methods of control and solution of this problem are discussed. |
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