Development of a new atom-based SI traceable electric-field metrology technique

Abstract

We are developing a fundamentally new atom-based approach for electric (E) field metrology. This technique has the capability of becoming a new international standard for E-field measurements and calibrations. Since this new approach is based on atomic transitions of alkali atoms (mainly caesium and rubidium atoms), the probe is self-calibrating and has a capability of performing measurements over a large bandwidth (from 10's MHz to the THz range). This new approach will lead to a self-calibrated, SI traceable, E-field measurement, and has the capability to perform measurements on a fine spatial resolution in both the far-field and near-field. We will report on the development of this new metrology approach, including the first fiber-coupled vapor-cell for E-field measurements, which allows for easier and more flexible measurements. We discuss key applications, including self-calibrated measurements, millimeter-wave and sub-THz measurements, field mapping, and sub-wavelength and near-field imaging. We show results for free-space measurements of E-fields, for measuring the E-field distribution along the surface of a circuit board, and for measuring the directivity pattern of a horn antenna.