High-sensitivity dynamical profilometry with a fiber-based composite interferometer

We proposed and demonstrated a fiber-based composite interferometer, which can perform surface profile measurements with sensitivity at the nanometer scale. With the proposed phase-compensation mechanism, the phase deviation due to the instability of the optical delay component and environmental perturbations can be simultaneously compensated. The measurement sensitivity and imaging speed can be significantly improved such that the system can be used as a high-speed, high-resolution, and wide-field dynamical imaging system. The axial precision of the system was examined to be 0.82 nm. High-resolution time-lapsed dynamical imaging of onion cells during dehydration processes were performed with this system with one frame captured in 75 s.