| Optical interconnects have been widely studied as a solution to the electrical interconnect bottleneck foreseen in computing systems. The mature technology of silicon CMOS electronics is well-established for high-speed information processing, while optical systems excel at information transmission. Future computing systems are likely to incorporate electronic components communicating along an optical channel that requires optoelectronic devices to convert signals from the electronic into the optical domain and vice versa.; Electroabsorption modulators designed for this application must be compatible with both the electrical and optical systems. This dissertation will begin with a discussion of the requirements for an optoelectronic modulator design. In particular, I will describe the advantages and challenges of 2D arrays of surface-normal modulators that operate over a wide wavelength range with a low voltage drive.; Two surface-normal modulator architectures will be presented. First, I will outline the design, fabrication and integration of an asymmetric Fabry-Perot AlGaAs/GaAs modulator. Following a post-integration cavity tuning step, this device achieved a contrast ratio of 3 dB over a wavelength range from 847 nm to 852 nm using a voltage drive of only 1 V. The second device, a novel design called the quasi-waveguide angled-facet electroabsorption modulator (QWAFEM), was simulated and fabricated in the InGaAsP/InP material system. An experimental contrast ratio of 3 dB over a 16 nm wavelength range near 1510 nm was measured for a voltage drive of only 0.8 V. To the best of our knowledge, no other reported low-voltage surface-normal modulator offers 3 dB of contrast ratio over such a wide wavelength range around 1.5 mum. Improvements to the QWAFEM design were simulated and a brief discussion of the advantages and practical challenges of such devices precedes the conclusion. |
