On-ground validation of the performance of the LISA Space-Based Gravitational Wave Observatory

The French contribution to the LISA Consortium, particularly on the instrumental side, focuses on developing Optical Ground Support Equipment (OGSE) to validate LISA’s performance before launch. More specifically, part of the French community’s mandate is to test and qualify the performance of the Interferometric Detection System (IDS). The IDS Test Set-Up is currently being developed to verify that picometer-level stability is achieved within the IDS and to characterize the TTL (tilt-to-length) coupling coefficients of the Optical Bench (OB) interferometers (the coupling between the relative angular misalignment of the beams and the interferometric length readout).In this contribution, I will briefly present the operating principles of the overall IDS Test Set-Up.