Nanowerk, June 15, 2023 Several technologies could benefit from the availability of fast and controllable conversion of terahertz light to visible light. An international team of researchers (Germany, Spain, UK) demonstrated that the exceptional properties and dynamics of electronic heat in graphene allow for a THz-to-visible conversion, which is switchable at a sub-nanosecond time scale. They showed a tunable on/off ratio of more than 30 for the emitted visible light, achieved through electrical gating using a gate voltage on the order of 1 V and that a grating-graphene metamaterial leads to an increase in THz-induced emitted power in the visible […]
Tag Archives: Frequency conversion
Changing color of light using a spatiotemporal boundary
Phys.org November 29, 2018 Effective temporal control of the medium is critical for frequency conversion. Researchers in South Korea designed a metasurface for the sudden merging of two distinct metallic meta-atoms into a single one upon ultrafast optical excitation. Sudden merging creates a spectrally designed temporal boundary on the metasurface by which the frequency conversion can be achieved and engineered. The technique provides a spatiotemporal boundary as a platform for freely designing and changing the spectral properties of the medium. Since frequency conversion can be observed even in weak light, this technique could be particularly useful in communication technology…read more. […]