Frequency multiplication of microwave radiation by propagating space-charge domains in a semiconductor superlattice

Abstract

We report on frequency multiplication of microwave radiation by propagating space-charge domains in a semiconductor superlattice; the domains were due to a negative differential mobility of miniband electrons. We irradiated an arrangement of two GaAs/AlAs superlattices, mounted in a rectangular waveguide system, with microwave radiation (frequency near 70 GHz) and observed the generation of harmonics; the conversion of radiation power to the third harmonic showed a remarkable efficiency (5%). A theoretical study, based on a drift-diffusion model for the miniband electrons, suggests that the microwave radiation has driven the formation and annihilation of space-charge domains and that the resulting anharmonic current was the source of the frequency-multiplied radiation. Our results indicate that frequency multiplication by space-charge domains in a semiconductor superlattice can be exploited for efficient generation of submillimeter-wave radiation.

Application of superlattice multipliers for high-resolution terahertz spectroscopy

“…13,[19][20][21][22][23][24][25][26][27] According to recent work by Scheurer et al, frequency multiplication by propagating dipole domains is feasible in a frequency range Ͻ 1, where ͑Ӎ10 −13 s͒ is the intraminiband relaxation time, that is, at least up to frequencies of about ϳ 1 THz. 28 The application of SLs as frequency multipliers in high-resolution THz spectroscopy is therefore a very promising approach whose realization for the use as a source for molecular spectroscopy is the purpose of the present work. Another interesting aspect of the SL device is that it is considerably more robust to electrostatic discharge than a Schottky diode, since the induced current is limited above the critical voltage U c , as can be seen from Fig.…”

Electroceramic Materials

“…Many dielectric crystals are currently applied as optical transducers by utilizing the Faraday effect (rotation of the plane of polarization of light by a magnetic fi eld), the electro -and magnetogyration (change of optic activity by a constant or timevarying electric or magnetic fi eld; Zheludev and Vlokh, 1983 ), the linear electrooptic (Pockels effect) and the quadratic electro -optic (Kerr) effect, in addition to effects related to frequency multiplication via higher harmonics (Scheuerer et al ., 2003 ). Only the electro -optic effects will be briefl y discussed in the following sections.…”

Semiconductor-Superlattice Parametric Oscillator as a Subterahertz and Possible Terahertz Radiation Source

“…It has been made use of the negative differential conductance for the development of superlattice oscillators driven by a static field; up to now, oscillation frequencies up to almost 200 GHz have been reached [13][14][15][16][17][18][19]. The nonlineartiy can be used for frequency multiplication [20][21][22], for heterodyne detection [23] and for direct detection of ultrashort sub-THz and THz radiation pulses, up to frequencies above 10 THz [24][25][26].…”