Measurement of the linear thermo-optical coefficient of Ga${}_{0.51}$In${}_{0.49}$P using photonic crystal nanocavities

Ga${}_{0.51}$In${}_{0.49}$P is a promising candidate for thermally tunable nanophotonic devices due to its low thermal conductivity. In this work we study its thermo-optical response. We obtain the linear thermo-optical coefficient $dn\mathrm{/}dT=2.0\pm 0.3\cdot {10}^{-4}{\mathrm{K}}^{-1}$ by investigating the transmission properties of a single mode-gap photonic crystal nanocavity.