Thermal management of VCSEL-based optoelectronic modules

Thermal management is critical to reliable optoelectronic modules based on vertical-cavity surface-emitting lasers (VCSELs). One critical thermal path to be managed is from a VCSEL to a case (heat sink), which is affected by packaging technologies and materials The measured VCSEL-to-case resistance of a laser with 8-/spl mu/m aperture was 1650/spl deg/C/W, and that of a 20-/spl mu/m device was 1070/spl deg/C/W. These thermal resistances are much larger than those for the edge-emitting lasers; advanced device and packaging technologies are being developed to reduce these resistances. To study the packaging effects, a three-dimensional (3-D) numerical model has been developed and calibrated by the measured data. The calibrated model was used to understand the difference in thermal behavior: 1) between a wire-bonded and a flip-chip VCSEL module, 2) between a single-VCSEL and an 8/spl times/8 VCSEL module, and 3) between a bottom-cooled and a top-cooled module.