Measurement of two-photon relaxation time by stark switching

This Letter report the application of the Stark-switching technique to study the two-photon coherent precession effect. Using this technique, I have made the first time-do-main measurement of the collision-induced dephasing time in a two-photon transition in NH3, and the result is compared with pressure-broadening measurements in the frequency domain. © 1977 The American Physical Society.