Cord identification technique for ultra-low bending loss fibers using higher order modes of visible light

► We propose a cord identification method using higher order modes of visible light. ► LP21 and LP02 modes at 650 nm and the LP31 mode at 532 nm are the most effective. ► An offset launch technique is employed to excite higher order modes. ► Using this method, a cord can be identified even with the naked eye.