Optical Gain in GaInNAs and GaInNAsSb Quantum Wells

Abstract

Abstract-We have measured the absorption, gain and spontaneous emission spectra of GaInNAsSb (3.3%N), GaInNAs (0.5%N) and GaInAs quantum well structures to compare their merits as laser gain media. The parameters describing the relations between peak gain and current provide only limited insight. From the analysis of absorption spectra we have determined the intrinsic properties of the structures, represented by the product [reduced density of states × matrix element × overlap integral], taking account of differences in operating wavelength, well width and confinement. We find only a small variation in this product across the samples. The GaInNAsSb structure has a low radiative recombination current due in part to its low photon energy and also to differences in conduction and valence band densities of states and less inhomogeneous broadening relative to GaInNAs. We speculate that Sb brings benefits as a surfactant producing more homogeneous wells so Sb may also be beneficial in structures at shorter wavelength. However, there is a large nonradiative current in GaInNAsSb and achieving further reductions in the non-radiative current is the major challenge in taking advantage of the good gain potential of this system.

Sub-250 nm light emission and optical gain in AlGaN materials

“…Alternatively, other approaches based on VSL technique with current injection, 25,26 Hakki-Paoli method, 27 and segmented contact technique 28,29 had also been used for characterizing optical gain in electrically injected quantum well lasers. The VSL technique is a very reliable and widely used method for the measurement of the optical gain coefficient in bulk materials, and it allows measuring unambiguously the net modal gain coefficient and the entire gain spectrum.…”

Electro-optic properties of GaInAsSb/GaAs quantum well for high-speed integrated optoelectronic devices

“…[12][13][14] An impact of N incorporation is the deterioration of the optical properties as defect induced nonradiative recombination (NRR) increases with increasing N concentration, 15 although recent work has shown that the addition of minimal amount of N ( 0:5%) together with a post-growth annealing treatment (680 C, 10 min) in GaInAsN QW hinder from formation of N-N pairs and clusters and thus do not lead to reduction in the intrinsic gain of the active region. 16 While the NRR could be advantageous for fast saturable aborbers (SAs) and electroabsorption modulators (EAMs) as an additional carrier recombination process, 17,18 it is largely detrimental for the gain properties, with lasing threshold densities remaining relatively high.…”

The role of photonics in energy

“…27 Recent work has reported the superior lasing characteristics of GaInNAs quantum well lasers with very low threshold. [28][29][30] By taking advantage of this progress, the integration of III-V multijunction cells with GaInNAs-containing alloys as one of the cell materials has enabled a record PCE of 43.5%. 31 Other materials including InGaN 32 and InN 33 are currently being pursued, while others such as GaAsBi 34 are being considered for multijunction solar cells.…”