Nonlinear spectroscopy of isotopic acetylene at /spl lambda/=1.5 /spl mu/m for absolute frequency stabilization of diode-pumped Er-Yb: Glass lasers

Non-linear spectroscopy of the acetylene molecule has been performed in the wavelength range from 1532 nm to 1549 nm, by means of a novel diode-pumped Er-Yb:glass laser with single frequency emission and narrow linewidth (<50 kHz over 1 ms). In order to saturate the acetylene lines, the gas sample was placed within an external high finesse resonator. Measurements of the spatial beam quality, linear polarization state and sensitivity to pump amplitude noise have been performed.