Photorefractive quantum wells: transverse Franz-Keldysh geometry

Resonant photodiffractive effect in semi - insulating multiple quantum wells

Received November 28, 1989; accepted April 10, 1990 We use semi-insulating multiple quantum wells to combine the holographic properties of the photorefractive effect with the large resonant optical nonlinearities of quantum-confined excitons. GaAs-AlGaAs multiplequantum-well structures are made semi-insulating by proton implantation. The implant damage produces defects that are available to tra...

Broadband low-dispersion diffraction of femtosecond pulses from photorefractive quantum wells

Photorefractive quantum wells operating by means of the Franz–Keldysh effect were designed to diffract a bandwidth of approximately 8 nm, nearly matching that of 100-fs pulses, with little dispersion in the diffracted pulses. Large diffraction bandwidths are engineered by adjustment of the well width of the quantum wells in a specific nonuniform distribution across the thickness of the device. ...

Contactless electroreflectance approach to study the Fermi level position in GaInNAs/GaAs quantum wells

A fruitful approach to study the Fermi level position in GaInNAs/GaAs quantum wells QWs has been proposed in this paper. This approach utilizes contactless electroreflectance CER spectroscopy and a very simple design of semiconductor structures. The idea of this design is to insert a GaInNAs quantum well QW into a region of undoped GaAs layer grown on n-type GaAs substrate. The possible pinning...

Quantum interference and control of the dynamic Franz-Keldysh effect: Generation and detection of terahertz space-charge fields

Two-wave-mixing dynamics and nonlinear hot-electron transport in transverse-geometry photorefractive quantum wells studied by moving gratings

The photorefractive response to an applied electric field is measured in a photorefractive quantum well, providing evidence in favor of the nonlinear transport in the device due to the hot electrons. The reduced mobility of the hot electrons limits the drift length, and thereby limits fringe overshoot. Thus the nonlinear transport prevents the slowing down of the grating writing rate for increa...