Optical Memory National Engineering Research Center, Department of Precision Instrument and Mechanics, Tsinghua University, Beijing 100084, China;
Optical Memory National Engineering Research Center, Department of Precision Instrument and Mechanics, Tsinghua University, Beijing 100084, China;
Optical Memory National Engineering Research Center, Department of Precision Instrument and Mechanics, Tsinghua University, Beijing 100084, China;
Optical Memory National Engineering Research Center, Department of Precision Instrument and Mechanics, Tsinghua University, Beijing 100084, China;
Optical Memory National Engineering Research Center, Department of Precision Instrument and Mechanics, Tsinghua University, Beijing 100084, China;
multilevel optical data storage; phase-change media;