Absolute frequency stabilization of two diode-pumped Er-Yb:glass lasers to the acetylene P(15) line at 1534 nm

Two identical diode-pumped bulk Er-Yb:glass lasers, operating at 1534-nm wavelength, have been independently locked to the P(15) rovibrational line of the acetylene molecule by the FM sideband technique. Measurements of the beat note between the two lasers show a long-term frequency stability of 170 kHz over a 1-h period and a short-term laser linewidth below 50 kHz over 1 ms. The Allan standard deviation of the beat frequency was measured yielding values below 10-10 for integration times between 10 ms and 1 s, reaching the 4×10-11 level at 0.1 s. © 1998 American Institute of Physics.