Transient refractive index measurements in XeF laser gas mixtures

Transient refractive index (TRI) measurements made in e-beam-pumped XeF laser gas mixtures as a function of energy loading are discussed. Both NF₃ and F₂ were used as halogen donors in a neon base. TRI due to halogen donor burnup and to plasma dispersion was measured at 578.4 nm in typical laser mixtures containing Xe and at 353.2 nm in mixtures without Xe. The net index of refraction of the mixtures decreased with increasing energy loading, resulting in a difference of about 50×10^-9 to 100×10^-9 between pumped and unpumped region at a typical loading of 150 J/1.