Magneto infrared absorption measurements have been performed in a highly doped GaAs quantum well which has been lifted off and bonded to a silicon substrate, in order to study the resonant polaron interaction. It is found that the pinning of the cyclotron energy occurs at an energy close to that of the transverse optical phonon of GaAs. This unexpected result is explained by a model taking into...

A narrow-linewidth mid-IR source based on difference-frequency generation of an amplified 1.5 microm diode laser and a cw Tm-doped fiber laser in orientation-patterned (OP) GaAs has been developed and evaluated for spectroscopic applications. The source can be tuned to any frequency in the 7.6-8.2 microm range with an output power of 0.5 mW. The measured characteristics of the OP-GaAs sample de...

Since the concept of doping superlattice was proposed by Esak and Tsu, the electronic properties of it were intensively investigated both theoretically and experimentally. Doping superlattices are structures which contain alternatively n-type and p-type doped regions of one semiconductor material and have a number of unique properties, such as tunable electronic structures, indirect band gap in...

Far infrared ~FIR! absorption, reflection, and transmission in heavily doped p-GaAs multilayer structures have been measured for wavelengths 20–200 mm and compared with the calculated results. Both Be ~in the range 3310– 2.6310 cm! and C (1.8310– 4.7310 cm)-doped structures were studied. It is found that the observed absorption, reflection, and transmission are explained correctly by the model ...

We report on the electromagnetic response of digital ferromagnetic heterostructures sDFHd: systems with d-doped MnAs layers separated by GaAs spacers of variable thickness syd. The gross features of the infrared conductivity of DFH samples are consistent with the notion that these digital structures are GaAs/Ga1−xMnxAs superlattices. This conclusion is supported by a combination of spectral wei...

A monolithically integrated guided-wave modulator has been realized by using molecular-beam epitaxial regrowth and ion-milling techniques. The guiding and modulating regions consist, respectively, of In-doped GaAs and GaAs/InO.34GaO. 6 6As strained-layer multiquantum wells. Modulation is achieved by field-enhanced electroabsorption in the multiquantum wells. The insertion loss of the modulator ...

Far infrared magnetophotoconductivity performed on high purity GaAs reveals the existence of fine structures in the resonant magnetopolaron regions. The fine structures are attributed to the presence of bound phonons due to multiphonon processes. We demonstrate that the magnetopolaron energy spectrum consists of bound phonon branches and magnetopolaron branches. Our results also indicate that d...

We observe the noise spectrum of electron spins in bulk GaAs by Faraday-rotation noise spectroscopy. The experimental technique enables the undisturbed measurement of the electron-spin dynamics in semiconductors. We measure exemplarily the electron-spin relaxation time and the electron Landé g factor in -doped GaAs at low temperatures and find good agreement of the measured noise spectrum with ...

Millimeter and sub-millimeter wave response of two-dimensional hot electrons in double delta doped GaAs quantum well is studied here incorporating deformation potential acoustic, polar optic, ionized background and remote impurity scatterings in the framework of heated drifted Fermi-Dirac distribution function. The inclusion of delta doping is found to enhance the two-dimensional electron densi...

The stability of a GaAs layer structure consisting of a thin ~10 nm! layer of low-temperature-grown GaAs on a heavily n-doped GaAs layer, both grown by molecular beam epitaxy, has been studied using a scanning tunneling microscope. The sample was exposed to the atmosphere between the layer growth and STM characterization. Tunneling spectroscopy shows both the GaAs band edges and a band of midga...