Multistable Cascaded Optical Resonators for Deflection Sensors

In this paper, a novel optical deflection sensor element comprised of two cascaded optical resonators is proposed and analyzed. The proposed structure is designed to operate in a multistable (input to output) regime. As the first resonator is equipped with a movable mirror, connected to a diaphragm in order to sense changes in deflection, the second resonator is filled with nonlinear material. It is theoretically demonstrated that such a structure has a novel memory property, aside from having the ability to yield instant deflection measurements. This novel property is attributed to the nonlinearity of the medium of the second resonator. Furthermore, the sensor's sensitivity, which is the ratio of the change in the output light intensity to the change in the induced deflection, is shown to be enhanced due to the multistable behavior of the proposed cascade optical resonators. This device possesses a promising potential for applications in future smart sensors.