Strobe imaging of electric fields by depolarization of Rydberg states of Hg

We present a new technique for imaging electric fields that takes advantage of the large field-dependent coupling of the Rydberg states of Hg. Specifi cally we demonstrate an optical scheme that takes advantage of the field-in duced mixing of the 6s((2) S)nd D and 6s((2) S)(n + 1)p P states of Hg. Wit h the appropriate laser probe of this mixing, 579.2 nm light is produced th at is directly related to the strength of the local electric field. This al lows strobe images to be made of the electric field surrounding an object o n a 50 ps timescale. We demonstrate the utility of this technique by probin g the electric field surrounding pads on a digital integrated circuit packa ge.