Phase Control of Few-Cycle Coherent Terahertz Radiation Pulses

We report a method to control the carrier-envelope phase shift in nearly single-cycle coherent terahertz (THz) radiation pulses, in which we used Kerr effect and two-photon absorption in the generated crystals due to the pump beam peak intensity. Dependence of relative carrier-envelope phase shift of THz pulses on the pump beam intensity in the ZnTe crystal was measured experimentally. Under our experimental condition, we measured that maximum relative phase shift is 0.29 radians.