Design of the iLocater Acquisition Camera Demonstration System

TL;DR

This paper presents the design of a single-mode fiber-based acquisition camera for a diffraction-limited spectrometer, aiming to improve radial velocity measurements of terrestrial planets by overcoming seeing-limited design limitations.

Contribution

It introduces a novel acquisition camera system utilizing adaptive optics for precise fiber coupling in a high-resolution spectrometer.

Findings

On-sky SMF coupling efficiency measurement planned for fall 2015

Design demonstrates potential to reduce modal noise and background radiation

Enables more accurate Doppler measurements of exoplanets

Abstract

Existing planet-finding spectrometers are limited by systematic errors that result from their seeing-limited design. Of particular concern is the use of multi-mode fibers (MMFs), which introduce modal noise and accept significant amounts of background radiation from the sky. We present the design of a single-mode fiber-based acquisition camera for a diffraction-limited spectrometer named "iLocater." By using the "extreme" adaptive optics (AO) system of the Large Binocular Telescope (LBT), iLocater will overcome the limitations that prevent Doppler instruments from reaching their full potential, allowing precise radial velocity (RV) measurements of terrestrial planets around nearby bright stars. The instrument presented in this paper, which we refer to as the acquisition camera "demonstration system," will measure on-sky single-mode fiber (SMF) coupling efficiency using one of the 8.4m primaries of the LBT in fall 2015.