| People | Locations | Statistics |
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| Naji, M. |
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| Motta, Antonella |
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| Aletan, Dirar |
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| Mohamed, Tarek |
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| Ertürk, Emre |
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| Taccardi, Nicola |
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| Kononenko, Denys |
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| Petrov, R. H. | Madrid |
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| Alshaaer, Mazen | Brussels |
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| Bih, L. |
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| Casati, R. |
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| Muller, Hermance |
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| Kočí, Jan | Prague |
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| Šuljagić, Marija |
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| Kalteremidou, Kalliopi-Artemi | Brussels |
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| Azam, Siraj |
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| Ospanova, Alyiya |
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| Blanpain, Bart |
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| Ali, M. A. |
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| Popa, V. |
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| Rančić, M. |
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| Ollier, Nadège |
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| Azevedo, Nuno Monteiro |
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| Landes, Michael |
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| Rignanese, Gian-Marco |
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Walther, Thomas
University of Sheffield
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (13/13 displayed)
- 2022Think outside the boxcitations
- 2022Long-Term Outcomes after Aortic Valve and Root Replacement in a Very High-Risk Populationcitations
- 2021Identity of the local and macroscopic dynamic elastic responses in supercooled 1-propanolcitations
- 2017Impact of buffer gas quenching on the 1S0 → 1P1 ground-state atomic transition in nobeliumcitations
- 2017Study of phase separation in an InGaN alloy by electron energy loss spectroscopy in an aberration corrected monochromated scanning transmission electron microscopecitations
- 2017Impact of buffer gas quenching on the $^1S_0 → ^1P_1$ ground-state atomic transition in nobeliumcitations
- 2017Impact of buffer gas quenching on the $^1S_0$ $to$ $^1P_1$ ground-state atomic transition in nobeliumcitations
- 2014A laser locked Fabry-Perot etalon with 3 cm/s stability for spectrograph calibrationcitations
- 2012Characterization of thickness, elemental distribution and band-gap properties in AlGaN/GaN quantum wells by aberration-corrected TEM/STEMcitations
- 2012Characterization of InGaN/GaN epitaxial layers by aberration corrected TEM/STEMcitations
- 2011Nanoscale EELS analysis of elemental distribution and band-gap properties in AlGaN epitaxial layerscitations
- 2010Electron microscopy of AlGaN-based multilayers for UV laser devices
- 2006Microstructural analysis of lignocellulosic fiber networkscitations
Places of action
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document
A laser locked Fabry-Perot etalon with 3 cm/s stability for spectrograph calibration
Abstract
Accurate wavelength calibration is crucial for attaining superior Doppler precision with high resolution spectrographs. Upcoming facilities aim for 10 cm/s or better radial velocity precision to access the discovery space for Earth-like exoplanets. To achieve such precision over timescales of years, currently used wavelength cal- ibrators such as thorium-argon lamps and iodine cells will need to be replaced by more precise and stable sources. The ideal wavelength calibrator would produce an array of lines that are uniformly spaced, narrower than the spectrograph resolution, of equal brightness, cover the entire wavelength range of the spectrograph, and whose frequencies do not change with time. Laser frequency combs are an extremely accurate and stable, albeit technically challenging and costly, option that has received much attention recently. We present an alter- native method that uses a Fabry-Perot (FP) etalon illuminated by a white light source to produce a comb-like spectrum over a wide wavelength range. Previous work focused on the development of passively stabilized FP etalons for wavelength calibration. We improve on this method by locking the etalon to an atomic transition, the frequency of which is known to < 2 x 10<SUP>-11.7</SUP> We use a diode laser to observe both the rubidium (Rb) D<SUB>2</SUB> transition at 780 nm and the etalon transmission spectrum. Saturated absorption spectroscopy is used to resolve the Rb hyperfine lines and precisely determine their locations. Since the etalon spectrum is probed with the same laser, the etalon can be locked by ensuring that one of its transmission peaks coincides with a particular Rb hyperfine peak (via either temperature tuning or a piezoelectric transducer incorporated into the etalon). By measuring the frequency of one etalon peak directly via comparison with the Rb, we remove any drifts or aging effects of the etalon that could cause problems for passively stabilized etalon references. We demonstrate a locking precision that is equivalent to a Doppler precision of 3 cm/s RMS. Our setup is simple and robust, can be used with various etalons, and works in the infrared as well as the visible part of the spectrum. The combination of low cost, ease of use, and high precision make this calibration system an attractive option for new spectrographs and as a retrofit for existing facilities....