Optothermal tuning of liquid crystal infiltrated InGaAsP photonic crystal nanocavities

A large and reversible all-optical tuning effect is demonstrated for liquid crystal (LC) infiltrated InGaAsP photonic crystal membrane nanocavities. The tuning is based on the change in the refractive index of the LC due to the large local heating caused by absorption of laser light by the semiconductor. Compared to opto-thermal tuning based on semiconductor heating alone, the effects with the LC are an order of magnitude larger and can be either redshifting or blueshifting, depending on the spatial distribution of the cavity mode’s polarization direction