Electro-optic sensor for static fields

• Published in: Applied physics. B, Lasers and optics Lasers and optics, 2019-11, Vol.125 (11), p.1-8, Article 212
• Main Authors: Grasdijk, J. O., Bai, X. F., Engin, I., Jungmann, K., Krause, H. J., Niederländer, B., Offenhäuser, A., Repetto, M., Willmann, L., Zimmer, S.
• Format: Article
• Language: English
• Subjects: Applied physics; Dipole moments; Electric dipoles; Electric fields; Engineering; Gas mixtures; Lasers; Light sources; Lithium niobates; Measuring instruments; Optical Devices; Optical fibers; Optics; Photonics; Physical Chemistry; Physics; Physics and Astronomy; Quantum Optics; Sensors; Signal monitoring; Time constant; Xenon 129
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-019-7326-5

A sensor has been developed for low frequency and DC electric fields E . The device is capable of measuring fields with Δ E = 4 (1) V/cm resolution. It is based on a Y-cut Z-propagation lithium niobate electro-optic crystal. For a particular commercially available bare crystal, we achieved an in air time constant τ c ( a i r ) = 6.4 ( 1.8 )  h for the decay of the electro-optic signal. This enables field monitoring for several hours. As an application, we demonstrated that a constant electric field E ext = 640  V/cm applied via external electrodes to a particular spherical glass container holding an Xe/He gas mixture decays inside this cell with a time constant τ E glass = 2.5 ( 5 )  h. This is sufficient for the needs of experiments searching for a permanent electric dipole moment in 129 Xe. An integrated electric field sensor has been constructed which is coupled to a light source and light detectors via optical fibers. The sensor head does not contain any electrically conducting material.