On-Axis Optical Bench for Laser Ranging Instruments in Future Gravity Missions

• Published in: Sensors (Basel, Switzerland) Vol. 22; no. 5; p. 2070
• Main Authors: Yang, Yichao, Yamamoto, Kohei, Dovale Álvarez, Miguel, Wei, Daikang, Esteban Delgado, Juan José, Müller, Vitali, Jia, Jianjun, Heinzel, Gerhard
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 07.03.2022; MDPI
• Subjects: Aperture; Climate change; Global positioning systems; GPS; GRACE; GRACE (experiment); Gravitational waves; heterodyne readout; inter-satellite ranging; Interferometers; Laser interferometry; Laser ranging; Lasers; Light; Satellites; Space missions; Thermal analysis; Thermal simulation; laser interferometry; heterodyne readout; inter-satellite ranging; GRACE
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s22052070

The laser ranging interferometer onboard the Gravity Recovery and Climate Experiment Follow-On mission proved the feasibility of an interferometric sensor for inter-satellite length tracking with sub-nanometer precision, establishing an important milestone for space laser interferometry and the general expectation that future gravity missions will employ heterodyne laser interferometry for satellite-to-satellite ranging. In this paper, we present the design of an on-axis optical bench for next-generation laser ranging which enhances the received optical power and the transmit beam divergence, enabling longer interferometer arms and relaxing the optical power requirement of the laser assembly. All design functionalities and requirements are verified by means of computer simulations. A thermal analysis is carried out to investigate the robustness of the proposed optical bench to the temperature fluctuations found in orbit.