精確的量測標準在物理學研究和工業技術發展均扮演著十分重要的角色，現行的頻率標準為銫原子6S1/2 F=3到F=4的躍遷頻率，9.192631770GHz，其量測不確定性逼近5×10-16，為準確度最高的基礎物理量，在本次光頻梳系統的架設中，我們利用摻鈦藍寶石飛秒鎖模雷射的高峰值功率和光子晶體光纖良好的非線性光學特性，產生一個在頻域上各模等間隔且頻寬涵蓋一個八度音的超寬光梳，此光梳波長範圍在500nm~1100nm，頻域上各模頻率為fn=frep+δ，其中frep為脈衝重複率 (repetition rate) 而δ為偏差頻率 (offset frequency)，在以鎖相廻路穩定脈衝重複率和偏差頻率後，便可以利用此光梳將極高的光頻分解為接近微波頻率標準的參數，並以微波頻率標準為基準，對光頻實施直接量測，以提升光頻量測的準確度，在本實驗中，我們成功地完成了脈衝重複率和偏差頻率的鎖頻，光路架設方面我們採用較簡單的單臂自參考系統來作偏差頻率的量測，並探討其光程差補償的機制。在未來克服所有量測上的問題後，飛秒光頻梳的不確定性為可望優於10-11。

Accurate standards of measurement is very important for physical research and development of industrial technology. The current frequency standard is the microwave radiation corresponding to the transition between |6S1/2 ,F=3> and |6S1/2 ,F=4> of 133Cs, 9.192631770GHz. It’s uncertainty is approaching 5×10-16， It is the most accurate basic physical quantity at the present time. In our setup of optical frequency comb, we generate a wideband optical frequency comb spectrum in frequency domain based on Ti:Sapphire femtosecond mode-locked laser’s high peak power and photonic crystal fiber’s highly nonlinear optical properties. The spectrum is wider than an octave (Its’ wavelength range is from 500nm to 1100nm) and every comb lines are equal spacing in frequency domain. The frequency of nth comb line is fn=frep+δ, frep is repetition rate of mode-locked laser and δ is the offset frequency of the comb spectrum. After stabilizing frep and δ by phase lock loops, We can measure the optical frequency directly based on the microwave frequency standard by OFC to make a great improvement on the accuracy of optical frequency measurement, In this experiment, we stabilized repetition rate and offset frequency successfully, at the meanwhile, We also use the single arm self-reference system to simplify our framework of optical system, and investigate its’ mechanism of optical path difference compensation. After solving some problems in our OFC. We expect the uncertainty of our OFC will be better than 10-11.

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