The fabrication of InAlAs wire structures and InGaAs quantum wire structures on non-planer InP substrates with truncated ridges by molecular beam epitaxy is demonstrated. Indium-rich InAlAs epitaxial layers grown on top of ridges exhibit self-formation of electron-confining InAlAs wire structures. The InAlAs layers on top of the ridges lattice-matched to the substrate are obtained by the control of In flux during the growth. The InGaAs quantum wire structures have been fabricated on thus composition-controlled InAlAs barrier layers. The optical properties of the InGaAs quantum wires with composition-controlled InAlAs barrier layer are found to be better than that of the wires without compositional control.

We measured the longitudinal electric field of the electrical pulses with a rise time less than 1 ps on a coplanar transmission line by electrooptic sampling. The longitudinal component is a sharp pulse and is only observed at the wavefront. The transverse component has no overshoot or undershoot. The mixing of longitudinal component to the transverse component is discussed for C3v crystals whose electrooptic coefficient is large. We developed the method to estimate the longitudinal and the transverse component of the electric field by the polarization control of a probe light without changing the probe configuration which affects sensitivity severely. The waveform and the rise time of the transverse electric field were eatimated, for the first time, by subtracting the influence of the longitudinal component.