Simultaneous frequency locking of 1535 and 1562  nm lasers to a single Fabry-Pérot cavity

We report the simultaneous frequency locking of two single frequency lasers around 1535 and 1562 nm to a single ultra-stable Fabry-Pérot cavity, respectively. Frequency stabilities up to 398 and 391 kHz are achieved for the lasers, respectively, through the Pound-Drever-Hall locking technique, producing a large synthesized frequency around 3.395 THz with high relative frequency stability of 5.8×10^-8. Interferometric tests demonstrate that the phase fluctuation suppression is also realized for the lasers by two orders of magnitude. The results are especially beneficial for multi-wavelength interferometric measurement.