Temperature mapping and thermal lensing in large-mode, high-power laser diodes

The authors use high-resolution charge-coupled device based thermoreflectance to derive two dimensional facet temperature maps of a =1.55 m InGaAsP/InP watt-class laser that has a large 55 m2 fundamental optical mode. Recognizing that temperature rise in the laser will lead to refractive index increase, they use the measured temperature profiles as an input to a finite-element mode solver, predicting bias-dependent spatial mode behavior that agrees well with experimental observations. These results demonstrate the general usefulness of high-resolution thermal imaging for studying spatial mode dynamics in photonic devices. © 2006 American Institute of Physics. DOI: 10.1063/1.2388884 In semiconductor lasers, key parameters such as thresh-old current, efficiency, and wavelength are closely related to temperature. These dependencies are especially important for high-power lasers, in which device heating is the main cause of decreased performance and failure. Heat sources such as nonradiative recombination in the active region typically cause the temperature to be highly peaked within the device