Ovonic Memory Switching in Multimaterial Fibers

We demonstrate the fi rst rewritable memory in thermally drawn fi bers. A high tellurium-content chalcogenide glass, contacted by metallic electrodes internal to the fi ber structure, is drawn from a macroscopic preform. An externally applied voltage is utilized to switch between a high resistance (OFF) and a low resistance (ON) state; this in turn allows the fi bers to function as a memory device reminiscent of the ovonic switch. The difference between the ON and OFF states is found to be four orders of magnitude. The glass– crystal phase transition is localized to micrometer-wide fi laments, whose position can be optically controlled along the fi ber axis. An architecture that enabled the encoding of multiple bits per fi ber is described.