本論文所要呈現的是利用薄膜濾波器(thin film filter)與Mach-Zehnder 干涉儀(interferometer)的配合，達到可調式輸出雷射波長。在光源方面，是藉由摻鉺光纖方大器(Erbium-doped fiber amplifier)中的放大自發性福射(amplified spontaneous emission) 寬頻光源，接著以單模光纖(single mode fiber)與光纖迴圈反射鏡(fiber loop mirror)所構成的共振腔。在輸出波長方面，是使用薄膜濾波器來做為選擇輸出的雷射波長，藉由在光路中加上四個薄膜濾波器串接在一起，使四個特定波長藉由光纖迴圈反射鏡反射回到系統。利用兩個3db coupler 所致做出來的Mach-Zehnder 干涉儀機構，產生兩道頻譜圖形狀為弦波(sinusoidal waves)的圖形，其中兩道光相互有180°的相位差(phase difference)，接著打入兩兩串連的薄膜濾波器，再經過薄膜濾波器的drop-port進入光纖迴圈反射鏡走一圈後繞回來，回到分波多工器(wavelength-division multiplexing)的另一端也是一個光纖迴圈反射鏡而形成共振腔。若要產生wavelength-tunable是藉由Mach-Zehnder 干涉儀上的位移產生器(shifter)對兩光路產生不同的光程差造成頻譜會產生向右飄移，而可以選擇上部分光路或是下部分光路產生光輸出，與bending裝置的配合，bending裝置則是選擇是從否讓後半部薄膜濾波器產生光雷射，因此可以分別讓四種波長輸出。

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