Frequency-stabilized diode laser at 780 nm with a continuously locked time over 100 h

Two extended-cavity diode lasers at 780 nm which are longtime frequency-stabilized to Rb;saturated absorption signals are reported.A high-performance frequency-locking circuit module using a first-harmonic detection technique is designed and achieved.Two lasers are continuously frequency-stabilized for over 100 h in conventional laboratory condition.The Allan standard deviation of either laser is estimated to be 1.3×10;at an integration time of 25 s.The system environment temperature drift is demonstrated to be the main factor affecting long-term stability of the stabilized lasers based on our correlation study between beat frequency and system environment temperature.