Phase change of Ge2Sb2Te5 under terahertz laser illumination
Kang Zhou,
Junyi Nan,
Jiabin Shen,
Ziping Li,
J. C. Cao,
Zhitang Song,
Min Zhu,
Boqu He,
Ming Yan,
Heping Zeng,
Hua Li
Affiliations
Kang Zhou
Key Laboratory of Terahertz Solid State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
Junyi Nan
State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
Jiabin Shen
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
Ziping Li
Key Laboratory of Terahertz Solid State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
J. C. Cao
Key Laboratory of Terahertz Solid State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
Zhitang Song
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
Min Zhu
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
Boqu He
State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
Ming Yan
State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
Heping Zeng
State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
Hua Li
Key Laboratory of Terahertz Solid State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
Ge2Sb2Te5 (GST) is the typical phase change material (PCM) that can reversibly transform between the amorphous (a) and crystalline (c) states. Because the optical properties are phase-dependent, GST has been widely used in various photonic applications, such as optical switches and non-volatile memories. Currently, the photonic applications of the GST PCM have been demonstrated by employing lasers in visible and infrared wavelengths. Extending the photonic applications into other wavelengths is much demanded. Here, we investigate the phase change of the GST material illuminated by using a terahertz quantum cascade laser emitting around 2.5 THz. A finite-element simulation is employed to study the temperature and transmission changes induced by terahertz irradiation. It reveals that the phase change can be achieved and the transmission is reduced by 30% when the GST material is irradiated by the 2.5 THz laser light. Furthermore, a z-scan technique experimentally presents the phase change behaviors of GST illuminated by the terahertz light, which is visually proved by transmission electron microscopy. Our work paves a way for the applications of GST materials in the terahertz optical components, e.g., modulators and switches.
