本文介紹被動鎖模光纖雷射的架構，以及在光頻量測的應用。利用兩台鎖模光纖雷射操作在不同的重複率，透過簡單的步驟可以決定兩個光梳序梳的差值以及光梳序數，而且光梳序數的量測不受未知雷射頻率擾動的影響。這個方法完全自動化之後可以發展成為光頻率計數器，讓光頻量測和微波頻率量測一樣簡單。

Passively mode-locked fiber laser and the application in optical frequency metrology were introduced. The frequency of an unknlown laser was measured using two fiber laser combs operated in different repetition rates. The difference in mode number and the mode number were determined by simple processes. An optical frequency counter can be realized when the whole measurement process can be operated automatically. The measurement of optical frequency can be as simple as that of microwave frequency in the near future.