Heterogeneous and Monolithic Integration for Optical Interconnects

Louderback, Duane, Univ. of California, Santa Barbara; Sjoelund, Ola, Lucent Technologies; Hegblom, Eric R., Hewlett-Packard; Strzelecka, Eva M., Honeywell Technology Ctr.; Nakagawa, Shigeru, Univ. of California, Santa Barbara; Hu, Syn-Yem, Hewlett-Packard; Lofgreen, Daniel D., Univ. of California, Santa Barbara; Naone, Ryan L., Univ. of California, Santa Barbara; Ko, Jack, Picometrix

doi:10.1117/3.2525856.ch4

Book: Heterogeneous Optoelectronic Integration

Editor(s): Elias Towe

Author(s): Duane Louderback, Ola Sjoelund, Eric Hegblom, Eva Strzelecka, Shigeru Nakagawa, Syn-Yem Hu, Daniel Lofgreen, Ryan Naone, Jack Ko

Published: 2000

https://doi.org/10.1117/3.2525856.ch4

Author Affiliations +

Abstract

The large size and density of VCSEL arrays required for many applications place strict requirements on the VCSELs themselves. To avoid thermal problems and achieve single-mode operation, small, yet efficient, VCSELs are needed. The scaling of device characteristics such as threshold current density, differential efficiency, and wall-plug efficiency to small sizes is examined. Theoretical and experimental results on small, high-performance, tapered-aperture VCSELs are presented. The design, fabrication, and characterization of monolithically integrated refractive microlenses are examined. The microlenses are etched into the substrate side using mask shape transfer and can be used to eliminate or at least relax the tolerances on external optics. The design, fabrication, packaging, and characterization of monolithically integrated arrays of VCSELs and resonant-cavity photodetectors are presented. The devices are monolithically integrated without regrowth and the substrate emitting/detecting devices have lithographically aligned refractive microlenses integrated on the backside of the substrate. Arrays of these integrated devices were flipchip bonded onto high-speed submounts for modulation testing. High-speed and free-space link results are presented. Finally, monolithically integrated WDM pieshaped VCSEL arrays for short-distance multimode fiber links are presented. The dense WDM arrays are flip-chip bonded and cross talk results are discussed.