GaSb-based composite quantum wells for laser diodes operating in the telecom wavelength range near 1.55-μm

Abstract

We have investigated in detail the material, optical, and lasing properties of innovative GaInSb/AlInSb composite quantum wells (CQWs). The CQWs are confined by AlGaAsSb barrier layers, and a monolayer-thin AlInSb barrier layer has been inserted within the GaInSb QWs in order to achieve lasing emission within the telecom window. High-resolution X-ray diffraction, transmission electron microscopy, and photoluminescence spectroscopies reveal high structural quality of the samples. Inserting AlInSb layers allows wider QWs, and thus higher gain-material volume and CQW/optical mode overlap. This translates into better laser performances. Near room temperature, a threshold current of 85 mA and an output power of ∼30 mW/uncoated-facet under continuous wave operation are demonstrated at 1.55 μm with 10 μm × 1 mm laser diodes.

Thermal performance of GaInSb quantum well lasers for silicon photonics applications

“…GaInSb/GaSb composite quantum well (CQW) lasers have been grown by molecular beam epitaxy on 4°-off (001) silicon substrates emitting at 1.55 µm at RT in pulsed mode 7 ; near 1.55 µm in continuous wave (c.w.) on GaSb near RT 8 ; and more recently at 1.59 µm c.w. at RT on 6° miscut silicon 9 .…”

“…To commercialize on-silicon devices, it is important to understand the efficiency limiting mechanisms of the equivalent active regions grown on GaSb. In this paper we report on the thermal properties of GaInSb CQW devices on GaSb substrates 8 and use a range of experimental techniques to identify the principal processes limiting device performance 12 .…”

“…The insertion of AlInSb monolayers into the wider wells introduces additional confinement, counteracting the reduction in bandgap caused by the additional width. Further details of the fabrication of these devices is given in reference 8 .…”

Interband cascade Lasers with AlGaAsSb cladding layers emitting at 33 µm

“…Finally, the epitaxial growth of the SL structures requires more than a thousand cell shutter actuations which not only contribute to the accelerated aging of parts of the epitaxy equipment but also require a careful growth control of the InAs/AlSb interfaces which do not share any common atom [20]. On the contrary, the epitaxial growth of AlGaAsSb cladding layers by molecular beam epitaxy (MBE) is well mastered, as already demonstrated for GaSb-based diode lasers emitting between 1.55 µm to 3.7 µm [21,22,23]. The above-mentioned arguments suggest that ICLs including AlGaAsSb cladding layers would be amenable to deliver improved laser performance.…”