Application of Optical Multi-Stability to Deflection Sensors

In this work, the optical multi-stability is utilized in a deflection sensor element. We have found that a simple sensor, which consists of two cascaded Fabry-Perot resonators, has a novel memory property, besides having the ability to obtain instant deflection measurements. The essential operation of this device is conducted by an optically nonlinear refractive index change in the second resonator. As the second resonator is designed to be multi-stable, the first resonator has a movable mirror connected to a diaphragm, to sense a deflection change. We note that this proposed device has promising potential for the design of future smart sensors, which are further optically reconfigurable.