Abstract:
We employ two different methods to generate controllable elliptical polarization of teraherz (THz)
pulses. First, THz pulses are generated via optical rectification in nonlinear crystals using a pair of
temporally separated and perpendicularly polarized optical pulses. The THz ellipticity is controlled
by adjusting the relative time delay and polarization of the two optical pulses. We generate mixed
polarization states of single-cycle THz pulses using ZnTe, and elliptically polarized multicycle THz
pulses in periodically poled lithium niobate crystals. Second, we generate elliptically polarized THz
pulses by making a THz “wave plate” using a combination of a wire-grid THz polarizer and a mirror
to transform linearly polarized multicycle THz pulses into elliptical polarization.
