The Calibration System of the iLocater Spectrograph
arXiv:2607.27330
The paper describes the design and implementation of the calibration system for iLocater, a new near‑infrared extreme‑precision radial‑velocity spectrograph on the Large Binocular Telescope, focusing on the calibration light sources, fiber injection hardware, and switching architecture that avoids free‑space optics.
Abstract
iLocater is a new near-infrared, extreme precision radial velocity (EPRV) instrument delivered to the Large Binocular Telescope in the summer of 2026. The instrument utilizes single-mode fibers (SMFs) for light transmission, including its calibration systems. We present an overview of the iLocater calibration system, detailing the specific sources and the hardware required to inject calibration light into the SMFs. Furthermore, we discuss the hardware that efficiently switches between these sources and distributes the light to all necessary instrument locations, entirely eliminating the need for free-space propagation.
Submitted to SPIE Astronomical Telescopes + Instrumentation 2026, Paper 14149-462. 9 pages, 15 figures, 3 tables