CCD-TR Thermo-reflectance measurements

In order to measure and use the temperature profiles in lasers, we use charge coupled device (CCD) thermo-reflectance measurements. The reflectance of Au which forms the electrical contacts to these devices changes with temperature. The measurement setup is shown here.

thermoreflectance  reflectance_setup

 

tempgradient

The images are shown here under athermal operation. We can see that currents can vary greatly in the different sections to maintain the same wavelength of operation. We can also see that there can be quite significant temperature gradients along the mirror (grating) sections.
 

Reference

Athermal operation of multi-section slotted tunable lasers Wallace, M.J.; O’Reilly Meehan, R.; Enright, R.; Bello, F.; McCloskey, D.; Barabadi, B.; Wang, E.N.; Donegan, J. F. 2017 Optics Express 25(13) 14414-1442.