Precise displacement measurement in single-beam interferometry employing photonic metamaterial with effective zero-index.

As interferometry is the highest precision distance measuring technique, we proposed a mechanism of single-beam interferometry employing all-dielectric photonic metamaterial with effective zero-index as a means of precise displacement measurement. This mechanism offers a straightforward method for performing optical range-finding over multi-wavelength and sub-wavelength displacements in a compact uniaxial reflection configuration. The higher sensitivity and resolution can be achieved in this mechanism with the intrinsic accuracy of λ/4. The predesignated measuring device based on the proposed strategy could be directly scaled in dimensions to work at different frequency regions without the need for reconfiguration. Both numerical simulations and experiment have demonstrated its feasibilities and reliability. We believe it will have significant potential applications in the future optical measurement.