2016/12/21 by Ravinder K. Banyal, Ravinder Kumar Banyal, A. Reiners +3
Decision Sciences · Engineering · Physics and Astronomy · #Advanced Measurement and Metrology Techniques #Astronomy and Astrophysical Research #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Photonic and Optical Devices #Scientific Measurement and Uncertainty Evaluation #Semiconductor Lasers and Optical Devices #astro-ph.IM
paper · pdf · doi:10.48550/arxiv.1612.07431
18 pages, 12 figures, Accepted for publication in Journal of Astronomical Instrumentation
openalex publication_date 2016/12/21 · arxiv created 2017/01/24 · arxiv updated 2017/01/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We propose a dual cavity Fabry-Perot interferometer as a wavelength calibrator and a stability tracking device for astronomical spectrograph. The FPI consists of two adjoining cavities engraved on a low expansion monoblock spacer. A low-finesse astro-cavity is intended for generating a uniform grid of reference lines to calibrate the spectrograph and a high-finesse lock-cavity is meant for tracking the stability of the reference lines using optical frequency standards. The differential length changes in two cavities due to temperature and vibration perturbations are quantitatively analyzed using finite element method. An optimized mounting geometry with fractional length changes ΔL/L ≈ 1.5× 10-12 is suggested. We also identify conditions necessary to suppress relative length variations between two cavities well below 10-10~m, thus facilitating accurate dimension tracking and generation of stable reference spectra for Doppler measurement at 10 cms-1 level.