Novel rotation sensors are disclosed. sensors with a temporal resolution of one measurement per rotation. A transparent or absorbing substrate can be coated with a transparent thin film to produce a linear response in reflectance versus angle of incidence over a certain range of angles. The best results were obtained when the incident light was s-polarized For example. a Si substrate coated with an SiO2 film was used in constructing a reflection rotation sensor. Experimental results and an error analysis of this rotation sensor are presented.
Azzam, Rasheed M.A., "Sensor for Rotational Velocity and Rotational Acceleration" (1998). University of New Orleans Patents. Paper 5.