Toward a 1.54 mu m frequency standard with Er-Yb ((C2H2)-C-13)

A novel Er-Yb:glass quasi-monolithic diode-pumped laser has been developed to realize a high-accuracy frequency standard at 1.54 mum based on saturated absorption of isotopic acetylene, This compact oscillator shows low amplitude- and frequency- noise, wide wavelength tunability (similar to 20 nm), and continuous output power in excess of 20 mW with excellent Linear polarization (similar to 30 dB extinction ratio). Employing this laser source sub-Doppler spectroscopy of the acetylene around 1.54 mum has been performed. To obtain the necessary saturation intensity (similar to3.5 W/mm(2)), the absorbing sample is placed inside a Fabry-Perot cavity with a Finesse of similar to 150. The dispersion signal of the sub-Doppler resonance, useful to stabilize the laser frequency, has been obtained by dithering the Fabry-Perot piezo and employing a lock-in detection scheme.