Free-space transient magneto-optic sampling

We demonstrate a free-space magneto-optic sampling system to measure the transient magnetic component of a freely propagating terahertz beam. Preliminary results using two magneto-optic sensors are presented. A detection sensitivity of 10(-7) T of the picosecond magnetic field in a standard pump/probe configuration is obtained. In the current orthogonal geometry, a 13 ps risetime of the free-space magneto-optic signal is measured. A temporal resolution limited only by the material spin relaxation time in a velocity-matched geometry is anticipated. (C) 1997 American Institute of Physics.