ABSOLUTE FREQUENCY STABILIZATION OF 2 DIODE-PUMPED ER-YB-GLASS LASERSTO 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) rovibratio nal line of the acetylene molecule by the FM sideband technique. Measu rements of the beat note between the two lasers show a long-term frequ ency stability of 170 kHz over a 1-h period and a short-term laser lin ewidth below 50 kHz over 1 ms. The Allan standard deviation of the bea t frequency was measured yielding values below 10(-10) for integration times between 10 ms and 1 s, reaching the 4 x 10(-11) level at 0.1 s. (C) 1998 American Institute of Physics. [S0003-6951(98)02439-5].