Maximizing opto-elastic interaction using topology optimization

When a photonic device is subjected to a mechanical load, there are two effects which change the optical response relative to the reference configuration. First, there is the geometrical effect caused by geometrical changes, i.e. the deformation of the reference geometry to the deformed geometry. Secondly, there is the photo-elastic effect which changes the refractive index through Pockel's coefficients as the material is strained. For the case of transverse electric modes, we study how the two effects change the material distribution which maximizes the change in the optical transmission properties when the device is subjected to a static mechanical pre-strain. Material distributions consisting of air inclusions in silicon are considered. The optimized material distributions are computed using topology optimization.