High-Power and High-Efficiency 650nm-Band AlGaInP Visible Laser Diodes Fabricated by Ion Beam Etching

High power and high-slope efficiency 650nm band real-refractive-index ridge waveguide AlGaInP laser diodes with compressive strained MQW active layer are formed by pure Ar ion beam etching process.Symmetric laser mesas with high perpendicularity,which are impossible to obtain by traditional wet etching method due to the use of a 15°-misoriented substrate,are obtained by this dry etching method.Laser diodes with 4μm wide,600μm long and 10%/90% coat are fabricated.The typical threshold current of these devices is 46mA at room temperature,and a stable fundamental-mode operation over 40mW is obtained.Very high slope efficiency of 1.4W/A at 10mW and 1.1W/A at 40mW are realized.

Formation and magnetic properties of Fe16N2 films prepared by ion-beam-assisted deposition

Fe-N films containing the Fe16N2 phase were prepared in a high-vacuum system of ion-beam-assisted deposition (IBAD). The composition and structure of the films were analysed by Auger electron spectroscopy (AES) and X-ray diffraction (XRD), respectively. Magnetic properties of the films were measured by a vibrating sample magnetometer (VSM). The phase composition of Fe-N films depend sensitively on the N/Fe atomic arrival ratio and the deposition temperature. An Fe16N2 film was deposited successfully on a GaAs (1 0 0) substrate by IBAD at a N/Fe atomic arrival ratio of 0.12. The gram-saturation magnetic moment of the Fe16N2 film obtained is 237 emu/g at room temperature, the possible cause has been analysed and discussed. Hysteresis loops of Fe16N2 have been measured, the coercive force H-c is about 120 Oe, which is much larger than the value for Fe, this means the Fe16N2 sample exhibits a large uniaxial magnetocrystalline anisotropy. (C) 1998 Elsevier Science B.V. All rights reserved.