A new type of CuPt ordered-phase (CuPt-A) with orientation in the [111]A and [1̄1̄1]A directions was found in Al0.5In0.5P grown at 520° C on exact (001)GaAs substrate by gas-source molecular-beam epitaxy. Weak formation of conventional CuPt-B type ordered phase was also observed in the same AlInP layer. The surface reconstruction observed by RHEED during the growth was (2×2). At a growth temperature of 560° C the surface reconstruction was (2×1) and only conventional CuPt-B was formed. A step array parallel to [1̄10] and descending towards [110] was found to promote formation of the CuPt [111]A variant.

We report the 1000 mW single mode operation of a planar blue‐violet laser diode with inner stripe waveguide. Kink‐free output surpassed 400 mW (CW) and 600 mW (50 ns pulsed, duty 50%) at temperatures up to 90 °C. Precise optical field design for narrow stripe waveguide as well as damage‐free stripe formation was a key to achieving watt class output. By utilizing buried AlN as optical and current confinement layers, a damage‐free inner stripe as narrow as 1.0 μm wide was successfully fabricated. Planar inner stripe structure also has the advantage of a small increase in the electrical resistance for such a narrow stripe, which is favorable for high power operations. The results here indicate the potential of this planar blue‐violet laser diode for high power applications as the next generation of optical disc systems. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Porous rare-earth oxides are promising emitters for thermophotovoltaic generation because rare-earth ions exhibit narrow-band thermal emissions in a photovoltaic-convertible wavelength range and the pores scatter light of unwanted wavelengths. However, the effects of pores on the emitter performance have not been studied well due to the complexity. In this letter, we reveal the effects by analyzing the thermal emission spectra of garnet (Yb3Ga5O12) emitters by using a Kubelka-Munk-(KM) like two-flux model. The model incorporates the effects of pores as dependences on porosity of the absorption and scattering coefficients of the emitters. The absorption and scattering coefficients are determined uniquely by fitting the model to the experimental results with the help of the KM transform. We demonstrate that the emitter performance can be maximized by optimizing the porosity.

Comparative study on the formation of the three types of ordered structures (TP-A,CuPt-A, and CuPt-B) on group III sublattice in III-III-V type alloys are made for four kinds of alloys of AlInAs, GaInAs, AlInP, and GaInP grown by gas source molecular beam epitaxy. The bonding energy difference between the constituent binaries of a IIIA - IIIB-V type alloy is demonstrated to be an important factor for the ordered structure formation. The implications of the result for the formation mechanism is discussed.

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