Aliased laser noise and TDI coupling with LISA On table
Léon Vidal, Hubert Halloin, Dam Quang Nam, Pierre Prat, Antoine Petiteau · Classical and Quantum Gravity · 2025
Abstract Various noise sources will impact the laser interferometer space antenna (LISA) interferometric measurements, particularly laser frequency noise, which will dominate by several orders of magnitude. To achieve the required sensitivity for gravitational wave detection, noise reduction methods, such as the time-delay interferometry (TDI) algorithm, must be employed and tested using both computer and instrumental simulations. For this purpose, the electro-optical simulator LISA On table has been used to generate realistic LISA signals at the APC laboratory. This experiment also allows the testing of a LISA phasemeter (PM) prototype. In this paper, we experimentally demonstrate the coupling between the TDI algorithm and the PM anti-aliasing filters, which leads to the appearance of aliasing and non-stationary noise at high frequencies. We also propose an analytical model that allows us to estimate the impact of this coupling on our data and to constrain the design of the cascaded integrator-comb filter for a simplified LISA constellation. In addition, we explore the periodicity and impact of this non-stationarity in the case of a simplified LISA-like constellation with linearly evolving arm length.