No abstract

This report describes the research accomplishments achieved under the LDRD Project "Radiation Hardened Optoelectronic Components for Space-Based Applications." The aim of this LDRD has been to investigate the radiation hardness of vertical-cavity surface-emitting lasers (VCSELs) and photodiodes by looking at both the effects of total dose and of single-event upsets on the electrical and optical characteristics of VCSELs and photodiodes. These investigations were intended to provide guidance for the eventual integration of radiation hardened VCSELs and photodiodes with rad-hard driver and receiver electronics from an external vendor for space applications. During this one-year project, we have fabricated GaAs-based VCSELs and photodiodes, investigated ionization-induced transient effects due to high-energy protons, and measured the degradation of performance from both high-energy protons and neutrons.

This report describes the research accomplishments achieved under the LDRD Project "Leaky-mode VCSELs for photonic logic circuits." Leaky-mode vertical-cavity surfaceemitting lasers (VCSELs) offer new possibilities for integration of microcavity lasers to create optical microsystems. A leaky-mode VCSEL output-couples light laterally, in the plane of the semiconductor wafer, which allows the light to interact with adjacent lasers, modulators, and detectors on the same wafer. The fabrication of leaky-mode VCSELs based on effective index modification was proposed and demonstrated at Sandia in 1999 but was not adequately developed for use in applications. The aim of this LDRD has been to advance the design and fabrication of leaky-mode VCSELs to the point where initial applications can be attempted. In the first and second years of this LDRD we concentrated on overcoming previous difficulties in the epitaxial growth and fabrication of these advanced VCSELs. In the third year, we focused on applications of leaky-mode VCSELs, such as alloptical processing circuits based on gain quenching. * L&M Technologies, Inc. 4 AcknowledgmentsThe authors acknowledge professor Kent D. Choquette for starting the leaky mode VCSEL experimental effort at Sandia and for encouraging us to further develop this technology. We thank G. Allen Vawter and Weng W. Chow for discussions of their work on gain quenched lasers. We thank L. Bao and professor Luke Mawst for helpful discussions of leaky mode VCSEL arrays. We thank Daniel M. Grasso and professor Kent D. Choquette for collaboration on coupled-cavity VCSEL research. We thank Preetpaul Devgan and professor Prem Kumar for collaboration on VCSEL-based optoelectronic oscillators. We also thank John Nogan for helping us to modify the PlasmaTherm 790 PECVD tool for automated dielectric DBR deposition. We gratefully acknowledge the expert technical assistance that was provided by Gary D. Karpen. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin