Development of Fiber Fabry-Perot Interferometers as Stable Near-infrared Calibration Sources for High Resolution Spectrographs

Abstract

We discuss the ongoing development of single-mode fiber Fabry-Perot (FFP) Interferometers as precise astro-photonic calibration sources for high precision radial velocity (RV) spectrographs. FFPs are simple, inexpensive, monolithic units that can yield a stable and repeatable output spectrum. An FFP is a unique alternative to a traditional etalon, as the interferometric cavity is made of single-mode fiber rather than an air-gap spacer. This design allows for excellent collimation, high spectral finesse, rigid mechanical stability, insensitivity to vibrations, and no need for vacuum operation. The device we have tested is a commercially available product from Micron Optics. Our development path is targeted towards a calibration source for the Habitable-Zone Planet Finder (HPF), a near-infrared spectrograph designed to detect terrestrial-mass planets around low-mass stars, but this reference could also be used in many existing and planned fiber-fed spectrographs as we illustrate using the Apache Point Observatory Galactic Evolution Experiment (APOGEE) instrument. With precise temperature control of the fiber etalon, we achieve a thermal stability of 100 $\mu$K and associated velocity uncertainty of 22 cm s${}^{-1}$. We achieve a precision of $\approx$2 m s${}^{-1}$ in a single APOGEE fiber over 12 hours using this new photonic reference after removal of systematic correlations. This high precision (close to the expected photon-limited floor) is a testament to both the excellent intrinsic wavelength stability of the fiber interferometer and the stability of the APOGEE instrument design. Overall instrument velocity precision is 80 cm s${}^{-1}$ over 12 hours when averaged over all 300 APOGEE fibers and after removal of known trends and pressure correlations, implying the fiber etalon is intrinsically stable to significantly higher precision.

12 pages, 17 figures. Accepted in PASP

References in corpus (4)

• The 2.5 m Telescope of the Sloan Digital Sky Survey
• A laser frequency comb that enables radial velocity measurements with a precision of 1 cm s${}^{-1}$
• High-precision wavelength calibration of astronomical spectrographs with laser frequency combs
• The PRL Stabilized High Resolution Echelle Fiber-fed Spectrograph: Instrument Description & First Radial Velocity Results

Cited by in corpus (19)

• State of the Field: Extreme Precision Radial Velocities
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE) Spectrographs
• CERES: A Set of Automated Routines for Echelle Spectra
• Instrumentation for the detection and characterization of exoplanets
• Kepler-445, Kepler-446 and the Occurrence of Compact Multiples Orbiting Mid-M Dwarf Stars
• Demonstration of a Near-IR Laser Comb for Precision Radial Velocity Measurements in Astronomy
• Overview of the spectrometer optical fiber feed for the Habitable-zone Planet Finder
• 2023 Astrophotonics Roadmap: pathways to realizing multi-functional integrated astrophotonic instruments
• Stabilizing a Fabry-Perot etalon to 3 cm/s for spectrograph calibration
• Radial velocity information content of M dwarf spectra in the near-infrared
• New wavelength calibration of the HARPS spectrograph
• Rubidium-traced white-light etalon calibrator for radial velocity measurements at the cm/s level
• Stable fiber-illumination for extremely precise radial velocities with NEID
• Frequency stability characterization of a broadband fiber Fabry-Perot interferometer
• Mapping the aberrations of a wide-field spectrograph using a photonic comb
• A Full Implementation of Spectro-Perfectionism for Precise Radial Velocity Exoplanet Detection: A Test Case With the MINERVA Reduction Pipeline
• The Habitable-zone Planet Finder Calibration System
• Deriving High-Precision Radial Velocities
• A Low-cost Environmental Control System for Precise Radial Velocity Spectrometers