| Recent dramatic progress in producing manufacturable 1.55μm VCSELs, to which a large contribution has been made by the efforts described in this dissertation, has enabled a number of interesting applications that make use of the technology, such as optical links with gain, all-optical amplifiers, analog repeaters, photon number amplifiers, amplifying wavelength converters, and loss-less signal tapping. While these applications can be more easily implemented with mature 850nm and 980nm VCSELs—in fact even with edge-emitters—the 1.55μm implementations in the surface-emitting configuration offer distinct advantages that makes the efforts worthwhile.; In each of these applications, the key enabling-component is the technology that allows the epitaxial integration of multiple diode junctions, either within a single optical cavity or multiple cavities. The aim of this project was the development of this and other enabling technologies as to be implemented in 1.55 μm multiple-active-region (MAR) vertical-cavity surface-emitting lasers (VCSELs) and the theoretical explanation for their characteristics. The MAR VCSEL is the main component in all of the aforementioned applications, and the purpose of this dissertation is to present an overview of the technological issues involved in the implementation of MAR edge-emitters and more importantly MAR VCSELs.; Long-wavelength MAR VCSELs and edge-emitters with greater unity differential quantum efficiency have been demonstrated in pulsed mode of operation. The differential efficiency, threshold current and voltage, and differential resistance scaling properties predicted by the theory developed in this dissertation have been verified. However, thermal conductivity limitations prevented room-temperature continuous-wave operation for MAR VCSELs. This and other limitations are analyzed and solutions are proposed. |
