Superior Temperature Performance of 1.3 ?m AlGaInAs-Based Semiconductor Lasers Investigated at High Pressure and Low Temperature

Abstract

AlGaInAs-based 1.3 mm lasers exhibit a reduced temperature sensitivity of the threshold current, I th , when compared with conventional InGaAsP-based devices. We have investigated this improvement both experimentally and theoretically. We observe that I th increases with increasing pressure in the AlGaInAs devices which we attribute to the dominance of radiative recombination. In contrast, a decrease of I th with pressure is observed in InGaAsP devices which we attribute to a large non-radiative Auger current, I Aug , which decreases with increasing band gap. From these measurements taken together with temperature dependence studies we conclude that I Aug accounts for $50% I th in InGaAsP devices, but it amounts to <30% I th in the AlGaInAs lasers leading to a lower temperature dependence of I th . Theoretical calculations suggest that this reduction in I Aug in AlGaInAs is a direct consequence of the larger conduction band offset leading to improved electron confinement and a reduced quantum well hole concentration at threshold, p QW , and hence a reduced CHSH Auger process.Introduction Of paramount importance in the development of the internet are reliable and temperature stable lasers emitting at 1.3 mm. Whilst it is possible to incorporate elaborate temperature stabilising electronics into the packages of 1.55 mm lasers for long haul (trans-oceanic) telecommunications, it is economically prohibitive to do this for 1.3 mm devices which are required for fibre-to-the home (FTTH) systems. 1.3 mm lasers have conventionally been fabricated using the InGaAsP/InP materials system. These lasers generally have good output characteristics but the temperature sensitivity of their threshold currents (I th ) has prevented them from being deployed in FTTH systems.Previously, using high pressure techniques, we have shown that the poor thermal performance of InGaAsP-based 1.3 mm and 1.5 mm lasers is due to an intrinsic nonradiative Auger recombination process [1]. There is currently great interest in developing 1.3 mm lasers using the AlGaInAs/InP materials system and devices based upon this material are already exhibiting very promising characteristics including a reduced temperature sensitivity of I th [2,3]. The extent to which I th varies with temperature if often quantified in terms of a characteristic temperature, T 0 , such that

Spectroscopic characterization of 1450 nm semiconductor pump laser structures for Raman amplifiers

“…As mentioned earlier, this was to improve device performance via the stronger confinement created by the higher barrier energy, and CB offset, and this should reduce carrier spillover effects and, consequently, the amount of Auger recombination. 9 As expected, sample C does indeed display two ER modulus peaks, from the unstrained waveguide core and tensile barriers ͑at 1.091 and 1.134 eV, respectively, see Fig. 5͒.…”

Carrier Dynamic Investigations of AlGaInAs Quantum Well Revealed by Temperature-Dependent Time-Resolved Photoluminescence

“…1.3–1.5 μm wavelength semiconductor quantum well (QW) lasers have great potential in the application fields of optical communications, eye-safety lidar and three-dimensional imaging [ 1 , 2 ]. Due to the large conduction-band offset and low valence-band offset, AlGaInAs series of III–V materials that take advantage of good high-temperature performance, suitable photon energy and high material gain have become indispensable for 1.3–1.5 μm InP-based laser diode [ 3 , 4 , 5 ]. AlGaInAs QW lasers exhibit higher modulation-speed, more superior high-temperature performance than the frequently-used InGaAsP/InP lasers [ 6 , 7 , 8 ].…”

Microscopic View of Defect Evolution in Thermal Treated AlGaInAs Quantum Well Revealed by Spatially Resolved Cathodoluminescence

“…An aluminum gallium indium arsenic (AlGaInAs) material system is crucial for semiconductor diode lasers emitting at 1.3–1.55 μm, which has been widely used in optical fiber communications and photonic integrated circuits (PICs) owing to its advantages of high-speed operation, large gain, and external quantum efficiency [ 1 , 2 , 3 ]. A zinc-blended AlGaInAs compressive strained quantum well (QW) has substantially better electron confinement and material gain performance than the commonly used InGaAsP system, due to a larger conduction band offset [ 4 , 5 ]. For 1.3-μm AlGaInAs multi-quantum wells (MQWs) ridge waveguide lasers, the thermal resistance was found to be 73.6 and 43.5 K/W for junction-up and junction-down mounting, respectively [ 6 ].…”