Abstract

We have measured the phase shift due to the transient index of refraction for an e-beam excited XeF laser mix. Large phase shifts have been predicted for this lasing species because of the asymmetric gain as a function of wavelength^1-3 and transient absorption due to excited Ne.⁴ Previous measurement of the phase shift using a discharge-excited XeF probe indicated a transient phase shift of 5 rad for a peak gain length of about 1.⁵ These phase shifts vary with pumping leading to limits on the beam quality due to nonuniform pumping. The measurement was done using a 1 m long by 10 cm high e-beam of 350 kV and 10 A/cm² and 1 μs duration pumping a mixture of 3 atm Ne, 10 Torr Xe, and 2 Torr NF₃. The phase shifts were measured using a Mach-Zender interferometer and a narrow-band probe laser.

© 1983 Optical Society of America