Abstract
We present a novel concept for a Thomson scattering diagnostic, based on a high-speed fiber optic spectrometer. The high-speed fiber optic spectrometer presented here translates a spectral measurement from the frequency domain into the time domain, thus requiring the use of only a single photodetector for spectral acquisition. The high temporal precision offered by the instrument gives rise to a number of advantages over traditional spectrometers, such as nearly background-free measurements and multiple uses of the same injected beam. Multiple uses of the same beam would enable greatly increased measurement rates, in the range of 10–100 MHz. The spectral range and resolution of the fiber spectrometer can be easily tailored to be optimized for the light source and experimental conditions by selecting different lengths of fiber, thus allowing for the proposed technique to exhibit high dynamic range when measuring many points simultaneously. Finally, due to the temporal separation of the background from the signal, these improvements are possible without the need for increased average input laser power.
| Original language | English |
|---|---|
| Pages (from-to) | 7045-7052 |
| Number of pages | 8 |
| Journal | Applied Optics |
| Volume | 59 |
| Issue number | 23 |
| DOIs | |
| State | Published - Aug 10 2020 |
Funding
Funding. U.S. Department of Energy (DE-AC05-00OR22725). Acknowledgment. This paper has been authored in part by UT-Battelle, LLC, under contract with the U.S. DOE. The U.S. government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). The authors would like to acknowledge Dr. W.J. Wadsworth from the University of Bath, United Kingdom, for fruitful conversations.