Two-dimensional optical coherence tomography for real-time structural dynamical characterization

•A 2D optical coherence vibration tomography with displacement resolution of ~0.1 nm is presented.•It is capable of real-time absolute displacement measurement of structural line vibrations.•It could obtain fast line vibration measurement without scanning.•It could capture modal parameters in one pulse excitation measurement without input information.•It could apply in low-frequency vibration measurement and response-only modal analysis.

We present a two-dimensional optical coherence vibration tomography (2DOCVT) system with an ultra-precision displacement resolution of ~0.1 nm that is capable of in site real-time absolute displacement measurement of structural line vibrations. Experimental results of sinusoidal, sweep and impulse vibrations were reported. The key figures of merit such as the 2DOCVT system could obtain fast line vibration measurement without scanning and it also could be used to capture structural modal parameters in one single impulse excitation measurement without any vibration excitation input information, making it attractive for the application in low-frequency vibration measurement and response-only modal analysis.