Frequency down-conversion of terahertz waves at optically induced temporal boundaries in GaAs waveguides.

ABSTRACT: In this study, the frequency down-conversion of terahertz waves is analytically and experimentally demonstrated at the temporal boundaries within a GaAs waveguide. The temporal boundary is established by photoexciting the top surface of the waveguide, thereby instantaneously increasing its electrical conductivity. This photoexcited waveguide supports a transverse electromagnetic (TEM) mode with a frequency lower than those of the transverse magnetic (TM) modes present in the original waveguide. At the temporal boundary, the incident TM mode couples with the TEM mode, resulting in frequency down-conversion. Subtracting the propagation loss from the frequency-converted components indicates that the frequency conversion occurs with an efficiency consistent with the analytical predictions. The

SUBMITTER: Takano K 

PROVIDER: S-EPMC11501523 | biostudies-literature | 2024 Jul

REPOSITORIES: biostudies-literature