Strong plasmon resonances have been observed in the terahertz transmission spectra (1–5 THz) of large-area slit-grating-gate AlGaN/GaN-based high-electron-mobility transistor (HEMT) structures at temperatures from 10 to 170 K. The resonance frequencies correspond excitation plasmons with wave vectors equal reciprocal lattice metal grating, which serves both as a gate electrode for HEMT and coupler between incident radiation. Wide tunability by applied voltage demonstrates potential these...

We propose a novel concept of terahertz lasing based on stimulated generation plasmons in planar array graphene resonant micro/nanocavities strongly coupled to radiation. Due the strong plasmon confinement and superradiant nature emission by plasmonic nanocavities, amplification waves is enhanced many orders magnitude at resonance frequencies. show that regime ensured balance between gain radiative damping.

The terahertz absorption spectrum of plasmon modes in a grid-gated double-quantum-well (DQW) field-effect transistor structure is analyzed theoretically and numerically using first principles electromagnetic approach shown to faithfully reproduce important physical features recent experimental observations. We find that the essential character response—multiple resonances corresponding spatial harmonics standing plasmons under metal grating—is caused by static modulation electron density...

We have solved the problem of diffraction terahertz radiation on a perfectly conductive gate strip that partially screens two-dimensional (2D) electron layer located at some distance from gate. Scattering and absorption spectra such structure reveal fundamental plasma resonance excited under shown enhancement factor may reach very high values (up to 60). However, for narrow strips (with width less than 100nm) resonant scattering length scatterer is shorter its by four orders magnitude, which...

The giant amplification and lasing of terahertz radiation due to stimulated generation plasmons in graphene with a distributed planar Bragg resonator strongly coupled THz are predicted. waves at the plasmon resonance frequencies is several orders magnitude stronger than it away from resonances. achieved when net gain approaches negative radiative damping resonant plasmons, which ensures high coherence self-excitation collective mode. It shown that dynamic frequency ranges as well energy...

We show that voltage variations at a short gate can effectively tune higher-order ungated plasmon resonances in field-effect transistors (FETs). These may be excited by incoming terahertz radiation with much greater efficiency than the gated resonances. calculate spectra of absorption frame rigorous electromagnetic approach, which allows us to estimate resistance. Based on calculation results, we explain behavior different terms alternating-current FET equivalent circuit. The results help...

Injection pumping of the pristine graphene is a promising alternative to optical pumping, but it not obvious how properly combine electronic and plasmonic features in one same device order obtain terahertz plasmon amplification with injection pumping. This paper shows that an amplified mode can be effectively excited at resonance frequencies active ungated region injecting (absorbing) gated parts periodic structure. Necessary conditions for lasing structure are found.

The authors present a theory of dc photoresponse in two-dimensional (2D) electron channel the grating-gated field-effect transistor irradiated by an electromagnetic wave terahertz frequency. determine photoinduced correction to source-drain voltage and demonstrate that it has resonant peaks when frequency external radiation coincides with 2D plasmon frequencies. is shown depend on asymmetric drag constant bias current. amplitude nonmonotonic temperature dependence maximum at elevated...

We have shown that the electromagnetic coupling of a grating-gate plasmonic detector to terahertz radiation can be considerably enhanced by placing onto membrane substrate and using narrow-slit grating-gate. The responsivity factor 50 as compared conventional on bulk due between plasmons radiation.

Plasmonic transport is considered as a replacement for electronic in low-dimensional systems like field-effect transistors, plasmons are faster than electrons. Plasmons graphene promising use at THz frequencies, but this research held back by the primitive state of circuitry plasmonic devices. This study employs an asymmetric periodic grating to solve problem effective excitation propagating graphene. The important role ``dark'' (weakly radiative) plasmon modes efficient revealed. approach...

We calculate the terahertz absorption spectrum of high-electron-mobility transistor with a short gate and long ungated channel regions show that main contribution to linewidth gated plasmon resonance can be attributed plasmon-plasmon intermode scattering. The results allow interpreting recent experimental on resonant detection by InGaAs nanotransistors. physics scattering is discussed efficiency this process quantitatively compared other possible damping mechanisms.

Results of theoretical investigation the cross-polarization conversion terahertz (THz) radiation by graphene metasurface formed a periodic array nanoribbons located at surface high-refractive-index dielectric substrate are presented. Giant polarization plasmon resonance frequencies takes place without applying external DC magnetic field. Pumping its direct optical illumination or diffusion pumping allows for compensating Drude losses in and leads to further enhancement conversion. It is...

The achievement of the laser regime upon excitation weak plasmon modes in structures based on active graphene has been theoretically investigated. ``acoustic'' two-layer and ``nonradiative'' gated noncentrosymmetric grating-gated are radiative damping gain rate strong calculated. possibilities changing by geometry structure considered. It is proposed to use with low for decreasing threshold periodic structures.

Abstract We calculate the spectra of resonant terahertz photoresponse associated with higher‐order plasmon resonances in a grating‐gated field‐effect transistor two‐dimensional electron channel. The dependence on both dc bias current and grating slit width is studied. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The work devoted to theoretical studies of the excitation plasmon modes in a graphene microribbon by an incident terahertz electromagnetic wave. problem is solved three-dimensional formulation taking into account edge-field effects at ends using integral equation method being developed authors. influence length (for constant width microribbon) on properties fundamental mode studied. Criteria for choosing either simplified two-dimensional or approaches studying microribbons are formulated.