Laser is one of the greatest inventions of the 20th century and ultrashort pulse mode-locked laser produced appeared in 1964. The generation of femtosecond pulse was first in dye lasers in the first realization in 1980s. The early 1990s, the emergence of Kerr-lens mode-locked femtosecond titanium-sapphire laser promotes the rapid development of femtosecond laser technology，mainly in sharply reduced pulse width and peak power increases. We get attosecond (attosecond, 1as = 10-18s) order of magnitude by higher harmonic.

Our research interests include time and frequency synchronization，optical frequency comb，ultrafast laser and bio-imaging，new laser and applications.

      Our group has completed the experiment at 120 km carrier-grade optical fiber, optical frequency comb as a carrier burst and using feedforward compensation techniques before digital technology and precise frequency and wavelength division multiplexing optical fiber transmission and two-way synchronization with high accuracy time synchronization. Frequency transfer instability reached 6.18 × 10-20 / 2000 s, the time synchronization accuracy of <40 ps. We also achieved important results in high-frequency optical comb (1GHz) and astronomical optical comb. We obtain a pulse train output with a repetition rate of 20MHz, the average power of 2.4mW, the pulse width 500fs using phase shift and nonlinear amplification loop mirror to lock the mode. We got small size, simple structure, short output pulse width Q-switched laser using the SESAM, the Pulse width was compressed to 6ps.