Finite difference analysis of thermal characteristics of CW operation 850 nm lateral current injection and implant-apertured VCSEL with flip-chip bond design

• Published in: Solid-state electronics 2002-05, Vol.46 (5), p.699-704
• Main Authors: Mehandru, R., Dang, G., Kim, S., Ren, F., Hobson, W.S., Lopata, J., Pearton, S.J., Chang, W., Shen, H.
• Format: Article
• Language: English
• ISSN: 0038-1101; 1879-2405
• DOI: 10.1016/S0038-1101(01)00329-X

The finite difference method was used to analyze the thermal characteristics of continuous wave 850 nm AlGaAs/GaAs implant-apertured vertical-cavity surface-emitting lasers (VCSELs). A novel flip-chip design was used to enhance the heat dissipation. The temperature rise in the active can be maintained below 40 °C at 4 mW output power with 10 mA current bias. By contrast, the temperature rise reaches above 60 °C without flip-chip bonding. The transient temperature during turn-on of a VCSEL was also investigated. The time needed for the device to reach the steady-state temperature was in the range of a few tenths of a millisecond, which is orders of magnitude larger than the electrical or optical switch time. Flip-chip bonding will reduce the shift of the wavelength, peak power, threshold current, and slope efficiency during VCSEL operation.