Adaptive whole-field LDV for real-time sub-nanometer characterization of LAM spatial dynamics

Large Aperture Mirrors (LAMs) are critical components of space- and ground-based telescopes and surveillance systems. The need exists in assessing temporal multiple modality dynamics of various types of LAMs, including recently developed mirrors with membrane support structure and 3D printed mirrors. This presentation discusses practical results for Whole-Field Laser Doppler Vibrometer (WF-LDV) - a newly developed instrument capable of instantaneous characterization of LAM’s vibrational spectra. Contrary to typical single beam scanning LDV or laser-beam array matrix LDV, the whole-field LDV used in this study operates in global mirror illumination mode while pixilation of the data is performed at the receive. Given the capacity of the WF-LDV to capture and characterize structural vibration in real time with negligible latency, it is possible to adaptively excite and probe the LAM allowing rapid convergence on resonant modes combined with Dynamic Mode Decomposition of the dynamics of the mode evolution.