Assistant Prof. Keisuke Takano and Prof. Fumiaki Miyamaru, along with their research group, have published their research results on frequency down-conversion with temporal boundary.
2024/5/23
【Key findings】
Assistant Professor Keisuke Takano and Professor Fumiaki Miyamaru from the Physics course, along with Lecturer Toshihiro Nakanishi from Kyoto University, Associate Professor Yosuke Nakata from Osaka University, and the group of Professor Keshav M. Dani from Okinawa Institute of Science and Technology Graduate University, have announced their research findings on frequency down-conversion of terahertz waves using temporal boundary.
Assistant Professor Keisuke Takano and Professor Fumiaki Miyamaru from the Physics course, along with Lecturer Toshihiro Nakanishi from Kyoto University, Associate Professor Yosuke Nakata from Osaka University, and the group of Professor Keshav M. Dani from Okinawa Institute of Science and Technology Graduate University, have announced their research findings on frequency down-conversion of terahertz waves using temporal boundary.
Frequency conversion of terahertz waves, which are at ultra-high frequencies and are difficult to obtain strong light sources for, has previously suffered from low efficiency with conventional methods. In contrast, frequency conversion of electromagnetic waves using temporal boundary offers conversion efficiency that does not depend on the strength of the light source, making it suitable for terahertz wave frequency conversion. The research group has previously demonstrated that by applying temporal boundary to terahertz waves propagating through semiconductor waveguides, high-efficiency frequency up-conversion can be achieved. However, suitable waveguide structures or conditions for frequency down-conversion had not been identified.
In this study, the research group theoretically identified and experimentally demonstrated conditions under which terahertz waves in waveguides can be converted to lower frequencies using temporal boundary. It was also revealed that the direction of polarization of the incident terahertz waves can select between frequency up-conversion and down-conversion. This research is expected to form the basis for arbitrary frequency conversion techniques essential for terahertz wave applications.
The research findings were published in the international journal Nanophotonics by DE GRUYTER on May 20, 2024.
In this study, the research group theoretically identified and experimentally demonstrated conditions under which terahertz waves in waveguides can be converted to lower frequencies using temporal boundary. It was also revealed that the direction of polarization of the incident terahertz waves can select between frequency up-conversion and down-conversion. This research is expected to form the basis for arbitrary frequency conversion techniques essential for terahertz wave applications.
The research findings were published in the international journal Nanophotonics by DE GRUYTER on May 20, 2024.
【Paper title and authors】
Title: ”Frequency down-conversion of terahertz waves at optically induced temporal boundaries in GaAs waveguides”
Authors: Keisuke Takano, Satoko Uchiyama, Shintaro Nagase, Yuka Tsuchimoto, Toshihiro Nakanishi, Yosuke Nakata, Joel Pérez-Urquizo, Julien Madéo, Keshav M. Dani and Fumiaki Miyamaru
Journal ：Nanophotonics 13, 3077 (2024)
DOI：DOI: 10.1515/nanoph-2024-0010
Title: ”Frequency down-conversion of terahertz waves at optically induced temporal boundaries in GaAs waveguides”
Authors: Keisuke Takano, Satoko Uchiyama, Shintaro Nagase, Yuka Tsuchimoto, Toshihiro Nakanishi, Yosuke Nakata, Joel Pérez-Urquizo, Julien Madéo, Keshav M. Dani and Fumiaki Miyamaru
Journal ：Nanophotonics 13, 3077 (2024)
DOI：DOI: 10.1515/nanoph-2024-0010