Epsilon near-zero all-optical terahertz modulator

E. Alvear-Cabezón , T. Taliercio (1, 2) , S. Blin (1, 3) , R. Smaali , F. Gonzalez-Posada (1, 2) , A. Baranov (1, 2) , R. Teissier (1, 2) , E. Centeno (4)

1 IES - Institut d’Electronique et des Systèmes
2 NANOMIR - Composants à Nanostructure pour le moyen infrarouge
3 TéHO - Térahertz, hyperfréquence et optique
4 IP - Institut Pascal

We propose an efficient optically actuated THz modulator based on an ultrathin epsilon-near-zero (ENZ) slab photogenerated in an InAs semiconductor. We experimentally demonstrate a modulation depth of 90% at 1 THz obtained with a continuous laser at irradiation lower than 10 W cm À2. Beyond the strong attenuation of the THz transmission provided by the ENZ absorption effect, we also report a broadband modulation of the THz waves from 1 to 10 THz. In addition, our experimental results show that the cutoff frequency of 3 dB attains 2 MHz in the dynamic modulation regime.

Domaines: Physique [physics]

E. Alvear-Cabezón, T. Taliercio, S. Blin, R. Smaali, F. Gonzalez-Posada, et al.. Epsilon near-zero all-optical terahertz modulator. Applied Physics Letters, 2020, 117 (11), pp.111101. ⟨10.1063/5.0012206⟩. ⟨hal-03009384⟩