Next-generation calculable capacitor using a tunable-laser interferometer

A new calculable capacitor with an operating range of 0.1 pF is being developed at NIST. Incorporation of Fabry-Perot displacement metrology employing a tunable laser will allow a continuous set of electrode displacements, as opposed to the discrete set in the current implementation. In addition, the reduced uncertainty in the displacement measurement will allow a considerably more compact apparatus, greatly minimizing errors arising from other sources.