Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7925603 | Optics Communications | 2018 | 8 Pages |
Abstract
On-sky tests conducted with an astro-comb using the Potsdam Multi-Aperture Spectrograph (PMAS) at the 3.5Â m Calar Alto Telescope are reported. The proposed astro-comb approach is based on cascaded four-wave mixing between two lasers propagating through dispersion optimized nonlinear fibers. This approach allows for a line spacing that can be continuously tuned over a broad range (from tens of GHz to beyond 1Â THz) making it suitable for calibration of low- medium- and high-resolution spectrographs. The astro-comb provides 300 calibration lines and his line-spacing is tracked with a wavemeter having 0.3 pm absolute accuracy. First, we assess the accuracy of Neon calibration by measuring the astro-comb lines with (Neon calibrated) PMAS. The results are compared with expected line positions from wavemeter measurement showing an offset of â¼5-20Â pm (4%-16% of one resolution element). This might be the footprint of the accuracy limits from actual Neon calibration. Then, the astro-comb performance as a calibrator is assessed through measurements of the Ca triplet from stellar objects HD3765 and HD219538 as well as with the sky line spectrum, showing the advantage of the proposed astro-comb for wavelength calibration at any resolution.
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
J.M. Chavez Boggio, T. Fremberg, D. Bodenmüller, C. Sandin, M. Zajnulina, A. Kelz, D. Giannone, M. Rutowska, B. Moralejo, M.M. Roth, M. Wysmolek, H. Sayinc,