| The boom in fiber optic communications has created a high demand for much lower cost lasers in the 1.3–1.6 μm wavelength range for both low cost vertical-cavity surface-emitting lasers (VCSELs) and high-power Raman pumps. This has led to the introduction of dilute nitrogen into GaInAs to reduce the bandgap sufficiently, resulting in a new long wavelength material grown on GaAs. This new material will provide a new platform for low cost and high-speed directly-modulated lasers that are essential for the rapid expansion of optical wide area networks, metro area networks, and local area networks. The requirements for these lasers are a broad operating temperature range (−10 to 90°C) and moderate output power (∼10 mW) in the fundamental mode. There is also a growing interest in higher power lasers, at similar wavelengths, as pumps for Raman amplifiers to expand the available bandwidth and increase power budgets. Research has shown that GaInNAs can be coherently lattice matched to GaAs while providing the proper bandgap energy. These GaAs-based lasers with dilute N can take advantage of the well-developed GaAs processing techniques and superior distributed Bragg reflector mirror technology for VCSELs.; This thesis presents new structures utilizing GaNAs barriers and a new quantum well material, GaInNAsSb, to achieve long-wavelength optical emission in post-annealed material. This increase is accompanied by a blue-shift in the bandgap energy. As a result, the distinct challenge of this material system is to achieve high quality material with sufficiently long wavelength emission. Introduction of nitrogen into the barriers reduces the blue-shift of luminescence by suppressing nitrogen out-diffusion from the quantum wells and decreasing carrier confinement in the quantum wells.; We utilize antimony, both incorporated into the crystal and used as a surfactant, to enable higher indium incorporation. GaNAs or GaNAsSb barriers also reduce the overall strain of the active region because high indium mole fraction quantum wells, GaInNAs and GaInNAsSb, are compressively strained and the GaNAs barriers are tensely strained.; The Molecular Beam Epitaxial growth and demonstration of high-efficiency long-wavelength multiple quantum well GaInNAs(Sb) ridge-waveguide laser diodes using GaNAs(Sb) barriers on GaAs substrate and longer wavelength photoluminescence are described in this work. The wide wavelength range coverage and high output power of GaInNAs and GaInNAsSb lasers grown on GaAs developed in this thesis make these great candidates for both transmitters and optical amplifiers for telecommunications. |
