High Spatial Resolution Thermal Imaging of Multiple Section Semiconductor Lasers

Temperature strongly affects output power and peak wavelength characteristics of active optoelectronic devices. In this paper we describe how thermoreflectance imaging technique can be used to obtain thermal maps of photonic devices under operation. Submicron spatial resolution and <0.1C temperature resolution has been achieved. Temperature non-uniformity is investigated in various multi section lasers and photonic integrated circuits. It is shown that large temperature variations can be developed over small regions on the order of 20-30 micrometers in diameter. By optimizing the thermal design of the device, we have achieved record level of damage free power dissipation in electro-absorption modulators integrated with multiple section lasers.