A high spatial resolution, high velocity resolution all-fiber laser Doppler vibrometry (LDV) based on heterodyne detection for vibration measurements is reported. A linewidth of 1-kHz single-mode continuous fiber laser, polarization-preserving fiber, and a telescope with 30-mm aperture are used in this LDV. With the inphase-quadrature circuit and the digital differentiating discriminator, a high velocity resolution of 96.9 nm/s and a high displacement resolution of 2.5 pm are obtained simultaneously with a glass attached to a piezoceramic transducer. These values correspond to the measurement uncertainties of vibration velocity and displacement within 4.14% and 4.6%, respectively.
© 2011 Chinese Optics Letters
Jianhua Shang, Shuguang Zhao, Yan He, Weibiao Chen, and Ning Jia, "Experimental study on minimum resolvable velocity for heterodyne laser Doppler vibrometry," Chin. Opt. Lett. 9, 081201-081201 (2011)