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Bi2Sr2CaCu2O8+\delta (Bi-2212) stacks of intrinsic Josephson junctions were fabricated by an acid-treatment process from inside a single crystal. The surrounding acid-treated product is a transparent material, BiOCl. During the process, an optical adhesive (NOA-61) was used to fix a piece of the crystal on a glass substrate and to coat the surface of the sample. The current-voltage characteristics of the stacks at T=77\ K exhibited large hystereses and multiple branches with voltage spacings of approximately 2–3 mV. Under an external microwave field in the frequency range of 2–18 GHz, clear Shapiro steps were observed at voltages with multiples of (h/2e)frf. In addition, the thermal cycling properties of the critical current (Ic) were investigated. No apparent degradation of the Ic was observed during repeated thermal cycling between 300 and 77 K. [ABSTRACT FROM AUTHOR]

An organic light-emitting diode with a photonic crystal formed between indiumtin-oxide (ITO) and organic layers is demonstrated. Improvements of 50 and 140% in luminance efficiency and peak intensity, respectively, are successfully achieved compared with samples without photonic crystals, due to the enhancement of light extraction efficiency for confined modes in ITO=organic layers by photonic crystal effect. [ABSTRACT FROM AUTHOR]

Investigated is spontaneous emission (SE) from quantum dots (QDs) embedded within a 2D, photonic crystal (PC) slab, from the viewpoint of redistribution of the excited carriers. SE lifetime was found to increase up to 15-fold, close to theoretically predicted value, by the 2D photonic-bandgap effect and 3D carrier confinement effect of QDs. Emission efficiency in the vertical direction was simultaneously increased 15-fold by excited-carrier redistribution. An artificial point-defect cavity introduced within the PC led to cavity-mode emission at extremely low excitation-power densities <0.4 W · cm-2. [ABSTRACT FROM AUTHOR]

Dynamic and external tuning of the operating wavelength of a channel add/drop device based on a two-dimensional photonic crystal slab is demonstrated. Thermo-optical effect, where the temperature increase is induced by the absorption of external light, is utilised for the tuning. The tuning speed is shown to be as fast as 20μs. [ABSTRACT FROM AUTHOR]