Details

Autor(en) / Beteiligte

• Di Gaspare, Alessandra
• Song, Chao
• Schiattarella, Chiara
• Li, Lianhe H.
• Salih, Mohammed
• Giles Davies, A.
• Linfield, Edmund H.
• Zhang, Jincan
• Balci, Osman
• Ferrari, Andrea C.
• Dhillon, Sukhdeep
• Vitiello, Miriam S.

Titel

Compact terahertz harmonic generation in the Reststrahlenband using a graphene-embedded metallic split ring resonator array

Ist Teil von

• Nature communications, 2024-03, Vol.15 (1), p.2312-2312, Article 2312

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2024

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Harmonic generation is a result of a strong non-linear interaction between light and matter. It is a key technology for optics, as it allows the conversion of optical signals to higher frequencies. Owing to its intrinsically large and electrically tunable non-linear optical response, graphene has been used for high harmonic generation but, until now, only at frequencies < 2 THz, and with high-power ultrafast table-top lasers or accelerator-based structures. Here, we demonstrate third harmonic generation at 9.63 THz by optically pumping single-layer graphene, coupled to a circular split ring resonator (CSRR) array, with a 3.21 THz frequency quantum cascade laser (QCL). Combined with the high graphene nonlinearity, the mode confinement provided by the optically-pumped CSRR enhances the pump power density as well as that at the third harmonic, permitting harmonic generation. This approach enables potential access to a frequency range (6-12 THz) where compact sources remain difficult to obtain, owing to the Reststrahlenband of typical III-V semiconductors. Compact sources in the frequency range of 6-12 THz are difficult to obtain due to optical phonon absorption in conventional III-V semiconductors. Here, the authors demonstrate third harmonic generation at 9.63 THz by optically pumping monolayer graphene coupled to a circular split ring resonator by using a semiconductor laser.