Indium gallium arsenic nitride antimonide: A novel material for long-wavelength semiconductor lasers

Long wavelength semiconductor lasers (1.3∼1.55 μm) are key devices in the optical fiber communication systems and the optical access networks. However, the conventional InGaAsP/InP laser diodes (LDs) have poor temperature characteristics due to their small conduction band offset, and it is difficult to realize InGaAsP/InP vertical cavity surface emitting lasers (VCSELs) due to the low refractive index contrast of this material system. Recently, InGaAsN was proposed as a new approach to realize long wavelength lasers due to its improved electron confinement and its compatibility with the well-developed VCSEL technologies based on GaAs substrates. But due to the large miscibility gap, the quality of InGaAsN/GaAs quantum wells (QWs) deteriorates rapidly with increasing N incorporation. In this work, we investigated the effect of adding Sb on the qualities of InGaAsN/GaAs QWs and proposed a novel material: InGaAsNSb for long wavelength semiconductor lasers.; InGaAsNSb/GaAs quantum wells were grown on GaAs (100) substrates by solid source molecular beam epitaxy. X-ray diffraction and reflected high energy electron diffraction studies indicate that introduction of Sb improves the crystal quality and acts in a surfactant-like manner. Transmission electron microscopy investigation directly confirms the suppression the 3-dimension growth and improvement of the interface and crystal quality. Enhancement of optical properties of InGaAsNSb/GaAs QWs was demonstrated by photoluminescence measurements and confirmed by performance of broad area QW laser diodes. 1.53 μm room temperature photoluminescence was achieved from InGaAsNSb/GaAs quantum wells, which is the longest emission wavelength reported for this material system.; We have achieved room temperature pulsed operation of 1.3 μm InGaAsNSb/GaAs QW lasers with a record low threshold of 1.02 kA/cm2. The characteristic temperature (T₀) and the emission wavelength temperature dependence are 92 K and 0.36 nm/°C for a InGaAsN:Sb/GaAs multiple quantum well (MQW) LD, which show enhanced temperature performance of InGaAsN:Sb/GaAs lasers compared with that of InGaAsP/InP lasers. Lasing was observed up to 105°C for the MQW LD, which is the highest reported operating temperature for InGaAsN-based laser diodes. We have shown that the addition of Sb clearly improves the quality of the InGaAsN material and the new InGaAsNSb material is a promising candidate for the fabrication of long wavelength VCSELs for the long haul optical communication applications.