1. Experimental demonstration of the combined arm- and cavity-locking system for LISA
- Author
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Valliyakalayil, Jobin Thomas, Wade, Andrew, Rabeling, David, Zhang, Jue, Shaddock, Daniel, and McKenzie, Kirk
- Subjects
General Relativity and Quantum Cosmology ,Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
Laser frequency noise suppression is a critical requirement for the Laser Interferometer Space Antenna (LISA) mission to detect gravitational waves. The baseline laser stabilization is achieved using cavity pre-stabilization and a post-processing technique called Time-Delay-Interferometry (TDI). To enhance the margins for TDI, alternate laser locking schemes should be investigated. A novel stabilisation blending the excellent stability of the arm with the existing cavity reference has been shown theoretically to meet the first-generation TDI margins. This locking system was designed to be implemented as a firmware change and have minimal or no changes to the LISA hardware. This paper experimentally verifies the hybrid laser locking technique by utilizing two references - an optical cavity, and an interferometer with delay imparted using 10 km of optical fiber. The results indicate the viability of the combination of arm-cavity locking system for LISA. They show the key benefits envisioned by this technique; suppression of the cavity fluctuations by the arm sensor (by 21 dB in this demonstration) and reduction of Doppler pulling of the laser frequency, a key technical challenge for arm locking., Comment: 11 pages, 13 figures
- Published
- 2024