An Er:Fiber Femtosecond Optical Frequency Comb for Measurement of the D₁ Line in Cold ⁶Li Atoms

In this paper, we demonstrate a home-made Er:fiber femtosecond optical frequency comb system. The system includes Femtosecond laser, detection and control of f(rep) and f(ceo), Spectral broaden and Beat unit. By controlling the intra-cavity electro-optic modulator and piezoactuator , the f(rep) is stabilized with high bandwidth and large range (about megahertz bandwidth and 3 kilohertz range),In-loop frequency instability of f(ceo) and f(rep) are 3.7 X 10(-18)/tau(1/2) and 1.8 X 10(-1)(3)/tau(1/2) respectively. By using highly nonlinear fiber and MgO: Periodically poled lithium niobate , the Spectral range of femtosecond optical frequency comb is extended from infrared 1520-1607 nm to 671 nm.This system can be commendably used in measurement of the absolute frequency of D-1 line in cold Li-6 atoms.