Effect of wall pressure and shear stress on embedded cylindrical microlasers

In this paper, we carried out numerical experiments to study the effect of the shear stress and the wall pressure on the optical mode shift of two embedded cylindrical microlasers. The optical cavities (laser) are encapsulated in a slab that is clamped at the bottom surface while the other sides of the slab are free-stress boundaries. When a uniform shear stress and pressure is applied on the top surfaces of the slab, the morphology of the optical resonators are perturbed. This leads to a shift in the optical modes [commonly referred to as the whispering gallery mode (WGM)] of the resonators. The effect of the geometry (size and position of the optical cavities) and materials properties on the optical mode shift are studied. The results show a linear dependency of the WGM shift on the applied external pressure. In addition, the optical mode shift is slightly dependent on the geometry and the material properties. The effect of the shear stress on the WGM shift shows a quadratic dependency and this nonlinearity is strongly dependent on the position of the resonators within the slab. The studies also show that the proposed configuration could be used as a sensor for simultaneous measurements of wall pressure and shear stress.