Oscillatory behavior of current in the forward current-voltage characteristics for InGaAs/InAlAs multiple quantum well pin diodes was observed at room temperature for the first time. This oscillation became extremely clear at low temperature (80 K), and the oscillatory bias voltage region shrank with decreasing the well numbers.

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Aging tests were carried out on as-cleaved InGaAs/GaAs strained quantum-well ridge waveguide lasers. Although the lasers have immunity to sudden failure and have degradation rate as low as 2×10−5 h−1, after over 6000 h of operation, they readily suffered facet oxidation. The measured oxidation rate was comparable to that of GaAs quantum-well lasers and one order of magnitude higher than that of lattice-matched InGaAs/InP lasers. This high oxidation rate is considered to be caused by light absorption in the vicinity of the facet where the band gap is reduced because of the stress variation from biaxial to uniaxial.

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The coupling between the CuO 2 layers has been studied in a series of six TmBa 2 Cu 3 O y (6.40 y 6.90) single crystals, together with a YBa 2 Cu 3 O 6.9 and a Bi 2 Sr 2 CaCu 2 O 8 crystal, in terms of the magnetically measured interlayer critical current. The Ginzburg-Landau thermodynamic anisotropies have been estimated too. As oxygen is removed, the coupling weakens and both and the anisotropy between inter-and intralayer critical current densities, , increases rapidly. The current anisotropy appears to be larger than , and increases as the temperature is reduced, whereas should be temperature independent. These results are discussed in terms of Abrikosov versus Josephson vortices, and their effective dimensionality; possible pinning mechanisms are considered.