在本論文中,我們建構一個三段式可調雷射(DBR Laser),藉由三個電極的電流調整出相對應的ITU波長,由於每一個ITU波長的輸出可由許多不同的電流組合而成,所以此篇論文著重在分析當切換至不同ITU波長時,不同電流組合搭配下所產生的變化,以及探討其中在波長切換時間上之差異,並建議使用者如何挑選出較合適的電流範圍。 In this paper, we design a three-section tunable DBR laser, which adjusts driving currents in the tri-electrode to generate various channels in the ITU-Band. Because many driving current combinations can generate the same ITU channel, we develop a result when different current combinations, and discuss the transience time in different channels. Finally, we discuss for the user how to select the current combinations in suitable range.