Role of aluminum oxide cladding layers in heat transfer in a semiconductor slab with photonic crystal

Abstract

To clarify the role of cladding layers in heat transfer in a laser diode fabricated using a photonic crystal, we theoretically investigate heat transfer in a semiconductor slab with a two-dimensional photonic crystal consisting of an array of air holes. For a photonic crystal laser, temperature increase may be a serious problem since air holes can cause poor heat transfer even if a large Q-factor reduces threshold current. We carry out simulations of heat transfer in a structure with AlO x layers that are naturally generated by oxidizing conventional AlAs cladding layers. Temperature changes in structures with and without AlO x cladding layers show that the AlO x cladding layers suppress temperature rise down to about 1/3 of that in the structure without AlO x cladding layers.

1.3 µm lasing of circular defect cavity photonic crystal laser with an AlO<i>_x</i> cladding layer

“…CirD laser using an AlO x cladding also an ultra-small threshold as other PhC lasers with membrane structures [16,17]. The output intensity increases with the increasing of excitation power up to about 1 mW without saturation, which should be attributed to the good thermal conductivity of AlO x cladding layer [18,19]. The threshold current of the PC laser with circular defect I th can be estimated by…”

Local stress-induced effects on AlGaAs/AlOx oxidation front shape

“…Furthermore, the use of a thick AlOx low index layer would improve thermal and mechanical properties due to the higher monolithic nature compared to the commonly used air-bridge PC slab structure. 14,15 In this work, we have combined dark-field electron holography, scanning electron microscopy (SEM), and numerical simulations to get an insight into the strain spatial distribution in partially oxidized GaAs/AlGaAs structures in which the oxidized layer thickness exceeds 500 nm. In the present work, we present a 2D mapping of the strain distribution around the oxide/semiconductor interfaces from which we have identified a link between the effect of the internal stress and the oxide front shape, and hence its effect on the oxidation kinetics within such thick layers.…”