Fiber-based probe for electrooptic sampling

A fiber-based electrooptic probe that can be incorporated into existing electrooptic sampling systems is presented. The probe is made by attaching an electrooptic crystal to the end of a standard optical fiber and thinned to a thickness of 1.6 mum using selective wet etching. Measurements of the electric field over a coplanar waveguide structure verify the probe´s ability to sense electric fields. The probe can be accurately placed a few micrometers over a test point by monitoring the power reflected back into the probe off of a conductor on a circuit under test