Universal phase relation between longitudinal and transverse fields observed in focused terahertz beams
Universal phase relation between longitudinal and transverse fields observed in focused terahertz beams
We directly observe longitudinal electromagnetic fields in focused freely propagating terahertz (THz) beams of radial and linear polarization. Employing electro-optic detection, which is phase sensitive, allows one to selectively detect longitudinal and transverse field components. A phase shift of π/2 between the transverse and longitudinal field components is revealed. This …