We study terahertz (THz) radiation transmission through grating-gate graphene-based nanostructures. We report on room-temperature THz radiation amplification stimulated by current-driven plasmon ...excitation. Specifically, with an increase of the dc current under periodic charge density modulation, we observe a strong redshift of the resonant THz plasmon absorption, followed by a window of complete transparency to incoming radiation and subsequent amplification and blueshift of the resonant plasmon frequency. Our results are, to the best of our knowledge, the first experimental observation of energy transfer from dc current to plasmons leading to THz amplification. Additionally, we present a simple model offering a phenomenological description of the observed THz amplification. This model shows that in the presence of a dc current the radiation-induced correction to dissipation is sensitive to the phase shift between oscillations of carrier density and drift velocity. And, with an increasing current, the dissipation becomes negative, leading to amplification. The experimental results of this work, as all obtained at room-temperature, pave the way toward the new 2D plasmon-based, voltage-tunable THz radiation amplifiers.
Plasmonic Helicity‐Driven Detector of Terahertz Radiation Gorbenko, Ilya V.; Kachorovskii, Valentin Yu; Shur, Michael S.
Physica status solidi. PSS-RRL. Rapid research letters,
March 2019, 2019-03-00, 20190301, Letnik:
13, Številka:
3
Journal Article
Recenzirano
Odprti dostop
A theory of the helicity‐driven plasmonic dc response of a gated two‐dimensional electron gas to terahertz (THz) radiation is developed. A general diagram of a plasmonic detector operating in ...different regimes is found and analytical equations describing all these regimes are derived. It is demonstrated that the helicity‐sensitive part of the response dramatically increases in the vicinity of the plasmonic resonances and oscillates with the phase shift between the excitation signals on the source and drain. The resonance line shape is an asymmetric function of the frequency deviation from the resonance. In contrast, the helicity‐insensitive part of the response is symmetrical. These properties yield significant advantage for using plasmonic detectors as helicity‐sensitive THz and far infrared spectrometers and interferometers.
A theory of the helicity‐driven plasmonic dc response of a gated two‐dimensional electron gas to terahertz radiation is developed. The helicity‐sensitive part of the response dramatically increases in the vicinity of the plasmonic resonances and oscillates with the phase shift between the excitation signals on the source and drain. The resonance line shape is an asymmetric function of the frequency deviation from the resonance.
This study reviews recent advances in room-temperature coherent amplification of terahertz (THz) radiation in graphene, electrically driven by a dry cell battery. Our study explores THz light–plasmon ...coupling, light absorption, and amplification using a current-driven graphene-based system because of its excellent room temperature electrical and optical properties. An efficient method to exploit graphene Dirac plasmons (GDPs) for light generation and amplification is introduced. This approach is based on current-driven excitation of the GDPs in a dual-grating-gate high-mobility graphene channel field-effect transistor (DGG-GFET) structure. The temporal response of the DGG-GFETs to the polarization-managed incident THz pulsation is experimentally observed by using THz time-domain spectroscopy. Their Fourier spectra of the transmitted temporal waveform through the GDPs reveals the device functions 1) resonant absorption at low drain bias voltages below the first threshold level, 2) perfect transparency between the first and the second threshold drain bias levels, and 3) resonant amplification beyond the second threshold drain bias voltage. The maximal gain of 9% is obtained by a monolayer graphene at room temperatures, which is four times higher than the quantum limit that is given when THz photons directly interact with electrons. The results pave the way toward tunable graphene plasmonic THz amplifiers.
We report on experimental studies of terahertz (THz) radiation transmission through grating-gate graphene-channel transistor nanostructures and demonstrate room temperature THz radiation ...amplification stimulated by current-driven plasmon excitations. Specifically, with increase of the direct current (dc) under periodic charge density modulation, we observe a strong red shift of the resonant THz plasmon absorption, its complete bleaching, followed by the amplification and blue shift of the resonant plasmon frequency. Our results are, to the best of our knowledge, the first experimental observation of energy transfer from dc current to plasmons leading to THz amplification. We present a simple model allowing for the phenomenological description of the observed amplification phenomena. This model shows that in the presence of dc current the radiation-induced correction to dissipation is sensitive to the phase shift between THz oscillations of carrier density and drift velocity, and with increase of the current becomes negative, leading to amplification. The experimental results of this work as all obtained at room temperature, pave the way towards the new 2D plasmons based, voltage tuneable THz radiation amplifiers.
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