Precise control of optical phase and coherent synthesis in femtosecond laser based optical frequency combs

Optical frequency combs are laser sources which are capable of generating discrete, equal-spaced and highly coherent comb modes. Optical frequency comb technique provides a significant bridge to transfer the stability between optical frequency and radio frequency. The advances of this technology greatly promote the development of precision spectroscopy, optical time/frequency transfer, optical frequency division, long-distance transfer of time/frequency references and high-precision distance measurement. Benefiting from the wide spectral outputs, femtosecond lasers have become the best choice for the fulfillment of optical frequency combs. Within the precise control of the repetition frequency and carrier-envelope offset frequency of the pulse train from femtosecond lasers, a stable optical frequency comb both in the time domain and frequency domain can be obtained. This dissertation presents the precise control of repetition rate, carrier-envelope offset frequency and coherent pulse synthesis in optical frequency combs.