We report two fiber components with the geometrical features etched directly on the fiber cladding. When fibers with etched corrugation structures are stretched or compressed longitudinally, lateral bending occurs. For multimode fibers, the lateral bending leads to attenuation. For two-mode or few-mode fibers, lateral bending causes modal coupling. Taking advantage of these effects, multimode fiber strain sensing elements and two-mode modal couplers are realized. The theoretical models and experimental results of these etched fiber components are presented. For quantitative characterization of the modal couplers, a novel polarization independent LP11 mode stripper was designed and implemented with etched fibers.