Highly Sensitive and Wide-Band Tunable Terahertz Response of Plasma Waves Based on Graphene Field Effect Transistors

Abstract

Terahertz (THz) technology is becoming a spotlight of scientific interest due to its promising myriad applications including imaging, spectroscopy, industry control and communication. However, one of the major bottlenecks for advancing this field is due to lack of well-developed solid-state sources and detectors operating at THz gap which serves to mark the boundary between electronics and photonics. Here, we demonstrate exceptionally wide tunable terahertz plasma-wave excitation can be realized in the channel of micrometer-level graphene field effect transistors (FET). Owing to the intrinsic high propagation velocity of plasma waves (>~108 cm/s) and Dirac band structure, the plasma-wave graphene-FETs yield promising prospects for fast sensing, THz detection, etc. The results indicate that the multiple guide-wave resonances in the graphene sheets can lead to the deep sub-wavelength confinement of terahertz wave and with Q-factor orders of magnitude higher than that of conventional 2DEG system at room temperature. Rooted in this understanding, the performance trade-off among signal attenuation, broadband operation, on-chip integrability can be avoided in future THz smart photonic network system by merging photonics and electronics. The unique properties presented can open up the exciting routes to compact solid state tunable THz detectors, filters, and wide band subwavelength imaging based on the graphene-FETs.

Recent Advances in Laser Utilization in the Chemical Modification of Graphene Oxide and Its Applications

“…[ 102 ] Plasma wave-related effects are powerful tools in realizing highly sensitive and widely tunable THz detection in graphene fi eld-effect transistors. [ 103 ] Moreover, plasmons can be used for the enhancement of THz emissions induced by ultrafast optical excitation from single-layer graphene. [ 104 ] It is important to mention that sinusoidally corrugated graphene sheets can be an environment suited for the generation of THz radiation.…”

Tailoring Active Far-Infrared Resonator with Graphene Metasurface and Its Complementary

“…Furthermore, Fig. 4b displays the reflection and transmission of graphene composite under different Fermi levels; it can be found that the both the cut dipole and ring modes grow up rapidly when the Fermi level is tuned from 0.21 to 0.55 eV due to improved coupling or harmonic oscillator strength [27]. From Fig.…”

“…It can be found clearly that similar resonance takes place at around 15 THz with relatively weak dependence on the separation between two unit cells indicating the localized nature of this dipole plasma resonance. In the ring structure, there is only electric dipole resonance with bonding and anti-bonding hybridized modes at different frequencies [23]. Considering the small size of the structures compared with the incident wavelength, the electrostatic approximation in which the self-consistent potential acting on the graphene is given by:…”

Ultra-Compact On-chip Electro-Optic Waveguide Ring Resonators Based on Asymmetric Au-(Pb, La)(Zr, Ti)O3-Au Structure

“…The integration of photonics circuitry with metal architectures has paved the way for the control of SPP modes with electrical signals [5][6][7]. Recently, various kinds of fast response and small footprint plasmonic devices based on EO effect, such as ring resonators [8][9][10][11], detectors [12], phase shifters [13], field effect transistors (FETs) [14], gratings [15], and optical switches/modulators [16,17], have been demonstrated. Among these devices, waveguide ring resonators (WRRs) are more convenient to be fabricated extreme compact.…”