Device-level photonic memories and logic applications using phase-change materials

Photonics is believed to be one of the best candidates for a future computing system, which can perform data storage and processing in an optical manner at extremely high speed and with unprecedented bandwidth. However, it’s essential yet difficult to build the electronic counterparts, such as non-volatile memories and logic devices, in optical manner. Researchers from the Advanced Nanoscale Engineering group, collaborated with University of Exeter (UK), University of Muenster (Germany) and Massachusetts Institute of Technology (USA) reported their latest results on integrated photonic memories and logic devices based on phase-change materials in Advanced Materials. Phase-change materials (PCMs), widely used in rewritable optical discs and phase-change memory applications, show a substantial difference in both electronic and optical properties between the amorphous and crystalline states. In photonic memory implementations, the authors developed an optical pulse width modulation (PWM) technic, successfully achieving multi-level and non-volatile photonic memories with complete random accessibility. Furthermore, they demonstrated programmable optical logic devices with logic “OR” and “NAND” achieved on just a single photonic memory device. Their study provides a practical and elegant technique to optically program multiple functions in photonic phase-change devices for future computing applications.