Long-term stable passive synchronization between two-color mode-locked lasers with the aid of temperature...

We demonstrate long-term stable passive synchronization between two-color Ti:sapphire (master) and Yb-doped fiber (slave) mode-locked lasers in the master-slave configuration. Active temperature stabilization suppresses the repetition fluctuation of the slave laser, and with the aid of temperature stabilization in combination with simple repetition locking of the master laser, long-term stable synchronization as long as 6 h was realized. The repetition rates of both lasers are locked in submillihertz precision. A timing jitter of 0.75 fs was obtained at a detection bandwidth of 350 kHz.