System, device, and method for detecting perturbations

Certain exemplary embodiments comprise a system comprising a spatially distributed multimode optical fiber; a pixelated photodetector configured to detect a plurality of optical signals provided from said fiber, a first portion of the optical signals indicative of modal conversion and a second portion of the optical signals indicative of modal interference, a predetermined area of said pixelated photodetector adapted to be illuminated by the first portion of the optical signals; and a signal processing module adapted to decode and interpret a plurality of detected variables related to the optical signals.