Subpicosecond imaging system based on electrooptic effect

This work presents an ultrafast, interferometric electrooptic sampling system that uses a two-dimensional detector array to image the electric field present on a device. Spatial and temporal resolution are comparable to conventional “point” electrooptic sampling systems, <5 μm and <1 ps, respectively. Voltage sensitivity is expected to be 270 mV and may achieve less than 4 mV with sensor cooling and a more effective electrooptic material. A coplanar silicon structure with 10-μm feature size would have a field sensitivity of 27 kV/m and 400 V/m, respectively. This compares favorably with the reported sensitivity of 10⁵ V/m for prior imagers and 10 V/m for point samplers. Applications for an E-field “imager” include characterization of field distributions in planar passive microwave devices, multiport analog and digital devices, and studying device and materials physics