Abstract
Broad-band vacuum ultraviolet fluorescence has been observed in Nd3+-doped LaF3 excited with an F2 laser (157 nm). Although a theoretical estimation predicted a substantial small signal gain at 172 nm, the fluorescence intensity measured as a function of excitation power or excitation length indicated no positive net gain. We found an extremely large transient absorption in the visible wavelength region, which is presumably caused by color-centers and prevents laser oscillation in the vacuum ultraviolet region.
