High-sensitivity extrinsic Fabry-Perot cantilever accelerometers were proposed and tested. Micro-machined 45° angled fiber was adopted to form the cantilever to measure the acceleration. The Fabry-Perot cavity was formed by the sidewall of the fiber and the inner surface of commercial ceramic sleeves. The stepped cantilever fiber was fabricated by etching method to improve the sensitivity without enlarging the cantilever's length or adding extra proof-mass. Detailed theoretical analysis, simulation and experimental results of the proposed accelerometers were given. The measured results were in good agreement with the simulated results. The proposed accelerometers show the advantages of high flexibility, simplicity, compactness and low-cost, which are expected to be applied in the field of miniaturized vector hydrophone and seismic monitoring.

For well-magnified imaging systems that satisfy the Nyquist criterion, camera pixels resolve the fine details provided by the objective lens. However, the mismatch in a space–bandwidth product (SBP) between the objective lenses and digital cameras leads to major sacrifices in the optical field of view (FOV). This Letter presents a framework of phase manipulating Fresnel lenses (PMFL) to bridge this SBP gap in quantitative phase imaging (QPI) modality. This framework breaks through the conventional design paradigm of interferometric QPI, converting it from the combination of individual optical elements to a direct phase transform of the optical field. The wide-field QPI is implemented by a single dynamic PMFL mask, which conducts differential interference and scans the optical FOV across the camera sensor. We built a microscopic platform equipped with the PMFL module to image both natural and artificial samples and expanded the FOV for a given camera by factors of 3 × 3, 2 × 2, and 4 × 1, respectively.