The LISA telescopes must exhibit an optical path length stability of Hzpm in the mHz observation band to meet mission requirements. The optical truss interferometer is a proposed method to aid in the ground testing of the telescopes, as well as a risk-mitigation plan for the flight units. This consists of three Fabry-Perot cavities mounted to the telescope which are used to monitor structural displacements. We have designed and developed a fiber-based cavity injection system that integrates fiber components, mode-matching optics, and a cavity input mirror into a compact input stage. The input stages, paired with return mirror stages, can be mounted to the telescope to form the optical truss cavities. We performed a thorough sensitivity analysis using various simulation methods to support the fabrication and assembly of three first-generation prototype cavities, each of which exhibited a satisfactory performance based on our models.
@article{arxiv.2305.19425,
title = {Optical Truss Interferometer for the LISA Telescope},
author = {Kylan Jersey and Ian Harley-Trochimczyk and Yanqi Zhang and Felipe Guzman},
journal= {arXiv preprint arXiv:2305.19425},
year = {2023}
}