Abstract

By combining an intracavity frequency-doubled ring dye laser with a bandwidth of 0.5 MHz and a collimated beam of diatomic free radicals, we succeeded in measuring LIF spectra of electronic transitions in the UV of OH (A²Σ⁺ ← X²Π at λ = 308 nm) and NH (A³Π ← χ³Σ⁻ at λ = 336 nm and c¹Π ← a¹Δ at λ = 324 nm) with a very high resolution. The linewidths of 12–15 MHz, which are determined by residual Doppler broadening due to molecular beam divergence, enable us to resolve and analyze the hyperfine structure of ground and excited states.

© 1986 Optical Society of America