Multi-beam optical displacement sensor

An apparatus and method for estimating a parameter of interest using values of a beam property from two or more electromagnetic beams that both converge in an optical displacement device. The apparatus may include a Fabry-Perot interferometer, a light source, and a detection array. The electromagnetic beams may be converged one or more of: the interferometer and a convergence device. At least one reflective surface of the interferometer may be operably coupled to an element receiving an external stimulus, such as pressure, force, and/or acceleration. The method includes using the apparatus.