We propose an approach to determine the carrier-envelope phase (CEP) of a terahertz few-cycle pulse by observing the field-free molecular orientation. We find that the degree of orientation sensitively depends on the CEP, providing a new route for measuring the CEP without phase ambiguity. By taking advantage of the field-free molecular orientation, an important effect of the CEP drift caused by the dephasing of the generating medium on the accurate measurement of the CEP value is eliminated.
© 2009 Optical Society of America
Original Manuscript: July 2, 2009
Revised Manuscript: September 5, 2009
Manuscript Accepted: September 15, 2009
Published: October 12, 2009
Chuan-Cun Shu, Kai-Jun Yuan, Wen-Hui Hu, and Shu-Lin Cong, "Determination of the phase of terahertz few-cycle laser pulses," Opt. Lett. 34, 3190-3192 (2009)