Abstract
A novel type of optical time domain reflectometry (OTDR) using a multimode laser source is shown, for the first time to our knowledge, to be capable of ultrahigh resolution of the order of 10μm. The main advantage of this method can provide a possibility of high-sensitivity becaus of the coherence properties of the multimode laser. The principle of operation and the detection of a multilayer less than 150μm in thickness are demonstrated. The method shows promise for detecting reflected signals from an optical waveguide memory or other optical objects.
