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type:Journal Article, Wannier-Stark localization in a pair of high quality lattice-matchedInGaAs/InP superlattices (SL) p-i-n diodes with wide (60 meV) and narrow(14 meV) electron miniband widths has been investigated by roomtemperature photocurrent (PC) response measurements. PC spectra as wellas PC versus reverse bias voltage characteristics of the SL samples exhibit aclear excitonic absorption edge redshifted due to the miniband formationand show distinct Stark ladder transitions, which evolve with the appliedelectric field. The transition energy fan diagrams are analyzed for the SLmodel potential structures using transfer matrix calculations. It is foundthat observed blueshifts of the absorption edge by decreasing the minibandwidth and by increasing the field exactly coincide with half of the transitionminiband width, thus providing the electroabsorption modulation withInGaAs/InP SL's. Good agreement of the transition energies is obtainedbetween theory and experiment, using band offset and effective massparameters proposed by Gershoni et al., Phys. Rev. B38, 7870 (1988)., source:http://www.sciencedirect.com/science/journal/01679317

Multi-dimensional heterostructures, such as quantum well wires (QWWs), have been theoretically predicted to have numerous attractive aspects, which lead workers to many attempts at fabricating them. Although several quantum confinement effects have been confirmed for conventional quantum well films (QWFs), for example, blue shifts of photoluminescence (PL) energy or observation of newly appeared quantized levels, there are almost no systematic data on QWWs. The reason for this is two fold. First of all, it is extremely difficult to fabricate optically-active QWWs which are small enough to exhibit lateral confinement effects and even if this difficulty is overcome, we are then forced with the task of systematically varying QWW size so as to examine these effects., This article is from 'Advanced Processing and Characterization Technologies. Fabrication and Characterization of Semiconductor Optoelectronic Devices and Integrated Circuits Held in Clearwater, Florida on 8-10 May 1991. American Vacuum Society Series 10,'AD-A254 162, p50-53.

The pulse broadening by group velocity dispersion can be balanced by the narrowing effect of self-phase modulation to form temporal solitons. The identical nonlinear Schrodinger equation describes the one-transverse-dimension balancing of diffraction and Kerr-medium nonlinear refraction. Some evidence for spatial solitons has been published for planar waveguides of CS2 and glass, both in Kerr (n2) media. Here we report soliton formation in a semiconductor gain medium which is amplifying rather than lossy, is accumulative rather than instantaneous, and is near resonance instead of far from resonance. The self-focusing semiconductor gain medium is obtained by current injection into the following planar waveguide structure. A crystal was grown by gas-source molecular beam epitaxy on an n-doped InP substrate: 1.0-micrometer-thick n-doped InP buffer; 0.6-micrometer-thick guiding layer consisting of n-doped In0.78Ga0.22AS0AS.55P0.45 and six 42-A Ga0.47In0.53 As/30-A Al0.48In0.52As quantum wells in the center, p-doped In0.78Ga0.22As0.55P 0.45; 2 micrometer of p-doped InP; and 0.1 micrometer of p-doped Ga0.47 In 0.53 As contact layer. Photolithography and chemical etching were used to leave 80-micrometer-wide strips. This structure lases at = 1.31 micrometer with a threshold current of 1.2 A for a length of 400 micrometer., This Article is from 'Integrated Photonics Research'. Volume 10, AD-A255 423, p102-103.