Thermal conductivity of bulk (Ref. 8) and (Ref. 10) as a function of temperature. The measured data were taken from Refs. 8 and 10, and mathematical models for these data were obtained through curve-fittings. Inset: schematic for illustrating the incorporation of a heat-spreading layer (a thermal-conductive thin-film) on top of a semiconductor optical waveguide. The two-layer antireflection coatings were not shown.
(a) Schematics of the device structure and chip-on-submount configuration. The two-layer antireflection coatings were not shown, (b) SEM images of the input facet of a good sample (left) and that of a sample of which the input facet was damaged by excessive pump power (right).
(a) Profile of the total absorbed power and total absorbed power density along the propagation axis. Inset: a meshed simulation model showing the boundary conditions used in the simulation (top), and an example of the temperature distribution in the device (bottom). (b) Characteristics of damage threshold as a function of HSL thickness. Inset: effective thermal conductivity of the and as a function of thin-film thickness at 300 K. The interfacial thermal resistance of the nonoriented and oriented were determined based on the improvement in thermal conductivity over nondoped which has a typical of 0.15 for noncrystalline thin films (Ref. 11 and verified in the analysis of Ref. 1).
Two-dimensional vector plots of the 3D thermal flux in a device with (a) no HSL, (b) a thick , (c) a nonoriented thick , and (d) an oriented thick viewing from the input facet of the device. The stated percentages of the thermal flux in the direction indicated by the arrows are relative to the total thermal flux in the device. Classification of the thermal fluxes into one of the four indicated directions are with respect to the four faces of the cross-sectional rectangle defined by the narrow core viewed from the input facet.
Article metrics loading...
Full text loading...