Experiments have been conducted to study the heat transfer of a porous channel subjected to oscillating flow. The surface temperature distributions for both steady and oscillating flows were measured. The local and length-averaged Nusselt numbers were analyzed. The experimental results revealed that the surface temperature distribution for oscillating flow is more uniform than that for steady flow. Due to the reversing flow direction, there are two thermal entrance regions for oscillating flow. The length-averaged Nusselt number for oscillating flow is higher than that for steady flow. The length-averaged Nusselt number for both steady and oscillating flows increase linearly with a dimensionless grouping parameter k*/kfDe/L1/2Pe*1/2. The porous channel heat sink subjected to oscillating flow can be considered as an effective method for cooling high-speed electronic devices.

High temperature photoluminescence up to 100°C was demonstrated from the p-doped ten-layer InAs∕InGaAs quantum dot (QD) laser structure. 1.3μm InAs QD lasers were fabricated using pulsed anodic oxidation from this structure. High output power of 882mW and low transparency current density of 5.9A∕cm2∕QD layer were obtained. Ground state (GS) lasing could be maintained from a QD laser with short cavity length of 611μm, corresponding to the maximum modal gain of 23.1cm−1 from this laser system. GS continuous wave operation up to 100°C was also demonstrated from an InAs QD laser (50×2500μm2).

The dependence of the ridge height on the performance of the ridge waveguide (RWG) lasers has been systematically studied. It was found that the optimum ridge height corresponds to an etching depth where all the p-doped layers above the active region were removed. InGaAsN triple-quantum-well RWG lasers with optimized ridge height were fabricated with pulsed anodic oxidation. The lowest threshold current density (Jth) of 711A∕cm2 was obtained from a 10×1300μm2 InGaAsN RWG laser. The corresponding transparency current density (Jtr) of the fabricated InGaAsN RWG lasers was 438A∕cm2 (equivalent to 146A∕cm2 per well).

An equivalent circuit model has been proposed to analyze the high performance of InPbased uni-traveling-carrier photodiodes (UTC-PDs) with novel dipole-doped structure. The validity of this model has been confirmed with experimental data.

Self-assembled GaInNAs quantum dots (QDs) were grown on GaAs (001) substrate using solidsource molecular-beam epitaxy (SSMBE) equipped with a radio-frequency nitrogen plasma source. The GaInNAs QD growth characteristics were extensively investigated using atomic-force microscopy (AFM), photoluminescence (PL), and transmission electron microscopy (TEM) measurements. Self-assembled GaInNAs/GaAsN single layer QD lasers grown using SSMBE have been fabricated and characterized. The laser worked under continuous wave (CW) operation at room temperature (RT) with emission wavelength of 1175.86 nm. Temperature-dependent measurements have been carried out on the GaInNAs QD lasers. The lowest obtained threshold current density in this work is~1.05 kA/cm 2 from a GaInNAs QD laser (50 · 1,700 lm 2 ) at 10°C. High-temperature operation up to 65°C was demonstrated from an unbonded GaInNAs QD laser (50 · 1,060 lm 2 ), with high characteristic temperature of 79.4 K in the temperature range of 10-60°C.