Thermal nonlinearity in coupled disk microresonators

Here we present detailed experimental analysis of temperature-induced nonlinearity in two coupled disk microresonators (see Fig. 1 (a)) excited via a tapered optical fiber by a tuneable laser source. Due to finite fabrication accuracy both disks have a small size mismatch and therefore the excitation strength for the symmetric and anti-symmetric eigenstate differs. The light tends to be localized mainly in one of the disks depending on if the symmetric or anti-symmetric eigenstate is excited.