Abstract-Enhanced Optical Modulation Depth of Terahertz Waves by Self-Assembled Monolayer of Plasmonic Gold Nanoparticles

http://onlinelibrary.wiley.com/doi/10.1002/adom.201600248/abstract

Ultra-large-area self-assembled mono­layers of gold nanoparticles are coated on the intrinsic silicon to boost the generation of electron–hole pairs upon laser illumination. As a result, larger optical modulation depth of terahertz wave can be obtained by the monolayer coated silicon in comparison with the bare silicon.

Abstract-High-speed and broadband terahertz wave modulators based on large-area graphene field-effect transistors

Qi Mao, Qi-Ye Wen, Wei Tian, Tian-Long Wen, Zhi Chen, Qing-Hui Yang, and Huai-Wu Zhang  »View Authors http://www.opticsinfobase.org/ol/abstract.cfm?uri=ol-39-19-5649 Optics Letters, Vol. 39, Issue 19, pp. 5649-5652 (2014) http://dx.doi.org/10.1364/OL.39.005649

We present a broadband terahertz wave modulator with improved modulation depth and switch speed by cautiously selecting the gate dielectric materials in a large-area graphene-based field-effect transistor (GFET). An ultrathin Al2O3film (∼60  nm) is deposited by an atomic-layer-deposition technique as a high-k gate dielectric layer, which reduces the Coulomb impurity scattering and cavity effect, and thus greatly improves the modulation performance. Our modulator has achieved a modulation depth of 22% and modulation speed of 170 kHz in a frequency range from 0.4 to 1.5 THz, which is a large improvement in comparison to its predecessor of SiO2-based GFET.

© 2014 Optical Society of America

Abstract-High-speed and broadband terahertz wave modulators based on large-area graphene field-effect transistors

Qi Mao, Qi-Ye Wen, Wei Tian, Tian-Long Wen, Zhi Chen, Qing-Hui Yang, and Huai-Wu Zhang  »View Author Affiliations

http://www.opticsinfobase.org/ol/abstract.cfm?uri=ol-39-19-5649

Optics Letters, Vol. 39, Issue 19, pp. 5649-5652 (2014)

We present a broadband terahertz wave modulator with improved modulation depth and switch speed by cautiously selecting the gate dielectric materials in a large-area graphene-based field-effect transistor (GFET). An ultrathin Al2O3film (∼60  nm) is deposited by an atomic-layer-deposition technique as a high-k gate dielectric layer, which reduces the Coulomb impurity scattering and cavity effect, and thus greatly improves the modulation performance. Our modulator has achieved a modulation depth of 22% and modulation speed of 170 kHz in a frequency range from 0.4 to 1.5 THz, which is a large improvement in comparison to its predecessor of SiO2-based GFET.

© 2014 Optical Society of America