Changes

=== NeoScan Electro-Optic Field Probes ===

A typical EO probe is composed of an optical fiber affixed with an EO crystal, whose bottom surface is coated with a dielectric reflective layer. Due to its broad measurement bandwidth and high spatial resolution, the EO measurement technique is a promising means to characterize RF systems such as microwave and millimeter-wave integrated circuits and antennas. Unlike the conventional electrical measurement techniques which require some type of metal structure for the resonant detection of an RF signal, [[NeoScan]]’s unique real-time EO electric field measurement method requires no metal components. As a result, the field perturbation caused by introducing the probe tip within the vicinity of a device under test (DUT) is significantly reduced.

=== Measuring Amplitude and Phase of Polarimetric Fields ===

A low noise 1550 nm laser diode is used as optical beam source. The optical connections are fiber-based. The beam is delivered to an optical probe. The polarization of the beam is modulated through an electro-optic crystal on the probe tip. The modulated beam is reflected back into the fiber, and back to the mainframe for analysis. An optical analyzer converts the polarization change of the beam into an amplitude change. The amplitude is linearly proportional to the strength of the external electric field at the probe-crystal location. The equation E=αV is used to calculate the electric field, where α is the calibration factor, or the slope between the electric field E (in V/m) and the measured EO signal V (in V/m/V). For instance, for a calibration factor of 1.082 V/m/V. a measured EO signal of 1000 V (0.001 V), corresponds to and electric field of 1.082 V/m/V  1000 V = 1082 V/m.

The [[NeoScan]] system is capable of measuring signals with bandwidths up to 20 GHz and signal levels as low as 1 V/m for optical probes with a 10 m PM fiber. Because the optical probes are free of metallic parts, it is possible to measure extremely high-field strengths since there are no free electron surfaces to generate arcing. The [[NeoScan]] can measure fields up at least 2 MV/m and possibly higher.