Electric field and temperature measurement using ultra wide bandwidth pigtailed electro-optic probes

Abstract

We present pigtailed electro-optic probes that allow a simultaneous measurement of high frequency electric fields and temperature using a unique laser probe beam. This has been achieved by the development of a novel probe design associated with a fully automated servo-controlled optical bench, initially developed to stabilize the electric field sensor response. The developed electro-optic probes present a stable response in outdoors conditions over time duration exceeding 1 hour, a frequency bandwidth from kHz to tens of GHz with a sensitivity of 0.7 V.m -1 .Hz -1/2 and a temperature accuracy of 40 mK.

Fully automated E-field measurement setup using pigtailed electro-optic sensors for accurate, vectorial, and reliable remote measurement of high-power microwave signals

“…The 2-parameters digital control system orientates the motorized quarter-and half-waveplate, whose orientations permit the real time computation of the relative phase shifts ∆φ and ∆ϕ. 10 This latter provides informations on the temperature of the EO crystal. Considering the small temperature variation applied to the EO crystal, the birefringence can be approximated to a linear function of the temperature T , leading in turn to…”

“…To dissociate those two thermal effects affecting the EO crystal, on the one hand, and the PMF, on the other hand, we need to control the ellipticity of the probe beam polarization state. 10 Then, the control of the orientation of the quarter-waveplate (element (2) in figure 3.b) by a second regulation loop, equivalent to the first one, allows to get a linearly polarized probe beam, regardless its orientation, as long as the optical powers I 3 and I 4 are balanced. Thanks to the Jones' formalism, we can show this latter condition is verified as long as the axes of the quarter-waveplate (element (6) in figure 3.b) make an angle of 45 about those of the Wollaston prism (element (7) in figure 3.b) placed upstream the photodiodes PD 3 and PD 4 .…”

Non-invasive vectorial electric field characterization with optical probes

“…EO crystals can be classified in two main categories: anisotropic crystals and isotropic ones. With anisotroopic crystals (LiTaO 3 , LiNbO 3 ,...,) [4], a simultaneous measurement of one component of the field and of the temperature can be achieved. On the other hand, isotropic crystals (ZnTe, BSO,...) [2] can lead to a temperature dependent-free full characterization of the transverse E field (simultaneous measurement of magnitude and orientation of the E-field vector).…”

Development and Application of Integrated Optical Sensors for Intense E-Field Measurement

“…( a ) Miniature Pockels Cell [34] (Copyright © 2008 OSA, Reprinted with permission); ( b ) Pockels Cell based on KDP crystal [41] (Copyright © 2011 IEEE, Reprinted with permission).…”