A method estimates a nonlinearity profile of a material. The method includes providing a magnitude of a transform of a measured nonlinearity profile measured from the material.
An acoustic sensor includes at least one photonic crystal structure having at least one optical resonance with a resonance frequency and a resonance lineshape. The acoustic sensor further includes a housing mechanically coupled to the at least one photonic crystal structure.
An optical sensor includes at least one optical coupler and an optical waveguide in optical communication with the at least one optical coupler. The optical waveguide is configured to receive a first optical signal from the at least one optical coupler.
This optical gyroscope uses a unidirectional coupled-resonator waveguide to enhance the Sagnac effect. Thus, this device offers greater sensitivity to rotation than conventional resonant or interferometric fiber-optic gyroscopes.