High-power single-mode 894 nm VCSELs operating at high temperature (> 2 mW @ 365 K)

In this study, we realize the high-power output of a single-mode 894 nm vertical-cavity surface-emitting laser (VCSEL) at high temperature. The effects of the dimensional parameters of oxide aperture and surface relief on the transverse mode and threshold gain of VCSEL were analyzed. Through collaborative optimization of the oxide aperture and relief, the VCSEL with 8 µm oxide aperture diameter and 5 µm surface relief inner diameter can operate at high temperature of 365 K with single-mode output power of 2.02 mW and side-mode suppression of 29.2 dB.

Electrical-stress driven oxidation in 940 nm oxide-confined VCSEL

In this work, accelerated stress tests have been performed on oxide confined vertical cavity surface emitting LASER arrays to study the formation of defects degrading the performance of the device. One such defect is an additional oxide volume forming at the oxide aperture edge, which is used for optical and electrical confinement. After producing an additional oxide volume the sample was investigated using transmission electron microscopy to estimate the oxidation speed. To produce further insights into the formation process, the temperature during such a stress test was estimated by experimentally measuring the thermal resistance, and by a thermodynamic transport simulation. Both methods produced very similar results showing a temperature increase of around 22 K for a dissipated power of 3.5 mW per emitter. However this temperature rise is very small when compared to oxidation models found in literature and should not be enough to promote the oxidation. This indicates the presence of a new enhanced oxidation mechanism, which could be connected to corrosion based failure mechanisms reported in literature.

Конструкция источника одиночных фотонов спектрального диапазона 1.3 μm с инжекционной накачкой на основе вертикального микрорезонатора с внутрирезонаторными контактами

Electrically-pumped optical microcavity single photon sources based on single quantum dots are investigated by numerical modelling techniques. Design of electrically driven 1.3 μm-range single photon source with intra-cavity contacts and multiply oxide aperture layers is proposed. About two times improvement in photon coupling efficiency into the single-mode fiber is demonstrated as compared with single photon source based on cylindrical micropillar.