Two-mode diode-pumped colour-centre laser with an intracavity absorbing methane cell

A two-mode laser based on the colour centres in an Li:RbCl crystal and pumped by several laser diodes was constructed. The tuning range was 2.7 — 3.28 μm. The use of a laser with an intracavity absorbing methane cell made it possible to observe saturated-dispersion resonances at the R-branch lines of the ν₃ band of the methane molecule with a spectral resolution of 300 kHz.