In the areas of communication technology, laser technology, and spectroscopic technology, Fabry-Perot resonators that can accurately control the wavelength of light are often used. The principle is that the resonance wavelength component determined by the distance between the two mirrors can be transmitted. In recent years, the ring-shaped AER series of KEMET's laminated piezoelectric actuators have been used for high-precision Fabry-Perot resonators, and the wavelength to be transmitted can be controlled. This type of piezoelectric actuator is ideal for Fabry-Perot resonators because they can translate mirrors without tilting and control the distance between two mirrors with high precision.