In-situ determination of astro-comb calibrator lines to better than 10 cm s(-1).

  title={In-situ determination of astro-comb calibrator lines to better than 10 cm s(-1).},
  author={Chih-Hao Li and A. G. Glenday and Andrew John Benedick and Guoqing Noah Chang and Li-Jin Chen and Claire E. Cramer and Peter Fendel and G{\'a}bor Fűr{\'e}sz and Franz X. K{\"a}rtner and Sylvain Gereon Korzennik and David F. Phillips and Dimitar D. Sasselov and Andrew Szentgyorgyi and Ronald L. Walsworth},
  journal={Optics express},
  volume={18 12},
Improved wavelength calibrators for high-resolution astrophysical spectrographs will be essential for precision radial velocity (RV) detection of Earth-like exoplanets and direct observation of cosmological deceleration. The astro-comb is a combination of an octave-spanning femtosecond laser frequency comb and a Fabry-Pérot cavity used to achieve calibrator line spacings that can be resolved by an astrophysical spectrograph. Systematic spectral shifts associated with the cavity can be 0.1-1 MHz… 
Operation of a broadband visible-wavelength astro-comb with a high-resolution astrophysical spectrograph
Searches for Earth-like exoplanets using the periodic Doppler shift of stellar absorption lines require 10  cm/s precision in the measurement of stellar radial velocity (RV) over timescales of years.
Astro-comb calibration of an Echelle Spectrograph
We describe recent work calibrating a cross-dispersed spectrograph with an "astro-comb" i.e., a high repetition rate, octave spanning femtosecond laser frequency comb; and a filter cavity suppressing
Wavelength calibration of a high resolution spectrograph with a partially stabilized 15-GHz astrocomb from 550 to 890 nm.
A visible astrocomb spanning 555-890 nm has been implemented on the 10-m Southern African Large Telescope, delivering complete calibration of one channel of its high-resolution spectrograph and an
Comparison of astrophysical laser frequency combs with respect to the requirements of HIRES
Precise astronomical spectroscopy with the forthcoming E-ELT and its high resolution spectrograph HIRES will address a number of important science cases,1 e.g. detection of atmospheres of exoplanets.
Laser-frequency-comb calibration for the Extremely Large Telescope: an OPO-based infrared astrocomb covering the H and J bands
The Extremely Large Telescope (ELT) will address an unprecedented optical wavelength range from 370 to 2400 nm, and its high-resolution spectrograph (HIRES) will require a laser frequency comb
Operation of a broadband visible ‐ wavelength astro ‐ comb with a high ‐ resolution astrophysical
A key requirement for wavelength calibration of an astrophysical spectrograph is broadband wavelength coverage, which in the green astro‐comb is primarily limited by the dispersion of the mirrors in
Optimization of filtering schemes for broadband astro-combs.
This paper analyzes the interplay of Fabry-Perot filter cavities with power amplifiers and nonlinear broadening fiber in the design of astro-combs optimized for radial-velocity (RV) calibration accuracy, and finds that even a small nonlinear phase can reduce suppression of filtered comb lines, and increase RV error for spectrograph calibration.
Demonstration of on-sky calibration of astronomical spectra using a 25 GHz near-IR laser frequency comb.
A 25 GHz laser frequency comb based on a cavity-filtered erbium fiber mode-locked laser is described and characterized and used as a radial velocity calibration source for the fiber-fed Pathfinder near-infrared spectrograph.
Calibration of an astrophysical spectrograph below 1 m/s using a laser frequency comb.
Two wavelength calibrators based on laser frequency combs were deployed at an astronomical telescope to calibrate a high-resolution astrophysical spectrograph integrated with a 1.5 m telescope and demonstrated calibration precision and stability sufficient to enable detection of changes in stellar radial velocity < 1 m/s.
Broadband Fourier-transform spectrometer enabling modal subset identification in Fabry-Pérot-based astrocombs.
A broadband Fourier-transform spectrometer (FTS) with a resolving power of R = 430,000 at 550 nm is demonstrated, and applied to the identification of comb subsets from a filtered 1‑GHz supercontinuum.


A laser frequency comb that enables radial velocity measurements with a precision of 1 cm s-1
The fabrication of a filtered laser comb with up to 40-GHz (∼1-Å) line spacing, generated from a 1-GHz repetition-rate source, without compromising long-term stability, reproducibility or spectral resolution is reported.
High‐precision wavelength calibration of astronomical spectrographs with laser frequency combs
ABSTRACT We describe a possible new technique for precise wavelength calibration of high-resolutionastronomical spectrographs using femtosecond-pulsed mode-locked lasers controlled by sta-ble
Laser Frequency Combs for Astronomical Observations
It is shown that tracking complex, time-varying systematic effects in the spectrograph and detector system is a particular advantage of laser frequency comb calibration, and this technique promises an effective means for modeling and removal of such systematic effects to the accuracy required by future experiments to see direct evidence of the universe's putative acceleration.
The exoplanet hunter HARPS: unequalled accuracy and perspectives toward 1 cm s-1 precision
We present results from the first two years of operations of the HARPS spectrograph installed on the ESO 3.6m telescope at La Silla Observatory, Chile. This instrument, primarily built to detect
A new Generation of Spectrometer Calibration Techniques Based on Optical Frequency Combs
Typical astronomical spectrographs have a resolution λ/°λ ranging between a few hundred to 200,000. Deconvolution and correlation techniques are being employed with a significance down to 1/1000th of
A proposed laser frequency comb-based wavelength reference for high-resolution spectroscopy
High resolution spectroscopy is the foundation for many of the most challenging and productive of all astronomical observations. A highly precise, repeatable and stable wavelength calibration is
Complete characterization of a broadband high-finesse cavity using an optical frequency comb.
In the group-delay dispersion measurement of additionally introduced optical elements the authors verify a 2fs(2) accuracy in a 2THz resolution bandwidth and find good agreement of the measured performance and the target design of a high reflectance dielectric mirror.
Astronomical spectrograph calibration with broad-spectrum frequency combs
Abstract.Broadband femtosecond-laser frequency combs are filtered to spectrographically resolvable frequency-mode spacing, and limitations of using cavities for spectral filtering are considered.
Precise measurements of optical cavity dispersion and mirror coating properties via femtosecond combs.
The high sensitivity of this approach is demonstrated with a precise determination of the group-delay dispersion of air inside a 40-cm long optical cavity, demonstrating an accuracy better than 1 fs2.
Fabry–Pérot filter cavities for wide-spaced frequency combs with large spectral bandwidth
We use low-finesse Fabry–Pérot cavities in series to generate frequency combs with a large mode spacing in a way that allows its application to a large optical bandwidth. The attenuation of laser