An optically-interrogated microwave-Poynting-vector sensor using cadmium manganese telluride

Abstract

A single <110> cadmium-manganese-telluride crystal that exhibits both the Pockels and Faraday effects is used to produce a Poynting-vector sensor for signals in the microwave regime. This multi-birefringent crystal can independently measure either electric or magnetic fields through control of the polarization of the optical probe beam. After obtaining all the relevant electric and magnetic field components, a map of the Poynting vector along a 50-Omega microstrip was experimentally determined without the need for any further transformational calculations. The results demonstrate that this sensor can be used for near-field mapping of the Poynting vector. Utilizing both amplitude and phase information from the fields in the microwave signal, it was confirmed for the case of an open-terminated microstrip that no energy flowed to the load, while for a microstrip with a matched termination, the energy flowed consistently along the transmission line.

Scattering of inhomogeneous circularly polarized optical field and mechanical manifestation of the internal energy flows

“…In the paraxial case (γ << 1), to which we are restricted in this paper, terms 2 γ and of higher order can be neglected, and Eqs. (11) - (18) reduce to [26] ( 2 0 These equations characterize the field with inhomogeneous energy distribution over the reference plane z = 0 [ Fig. 2(a)].…”

“…However, wide utilization of these instruments is hampered by difficulties in their experimental detection (visualization) and measurement. As far as we can judge, the only regular way of energy flow measurement relies upon determining the electric and, if necessary, magnetic vectors of the optical field followed by the Poynting vector calculation via the standard formulas [13,18,19]. In this situation, the possibilities for immediate detection and/or visualization of the internal flows become rather attractive and appealing.…”

Circular motion of particles suspended in a Gaussian beam with circular polarization validates the spin part of the internal energy flow

“…In contrast to the multitude of approaches to determine the energy density, the only regular way of determining the energy flow density relies upon measurements of amplitudes and phases of the electric (magnetic) field components [10,16,17] followed by Poynting vector calculation via the definition…”

Recent Advances in the Design of Electro-Optic Sensors for Minimally Destructive Microwave Field Probing

“…In practical respects, the reflective scheme is generally preferred, with a sensor tip as the terminal of the optical sensor and the light being modulated at the sensor terminal when it is exposed to an electric field. The reflected beams to be detected are efficiently returned from the sensor using a number of common methods: a mirror [7–9,13–15]; total internal reflection [11–13]; highly reflective surfaces from the device under tests [16]; or through fabrication of a resonator on the sensor plate [10]. …”