為因應高速傳輸的分波多工系統，頻寬需求越來越大，而波長可調雷射可做為分波多工系統之備用光源，也可用於光學量測與掃描元件與設備，具有使用上的彈性及便利。於本論文我們研製價廉的波長可調光纖雷射，它是利用可調光纖光柵來選定波長，我們同時架構出C頻帶、L頻帶與C+L頻帶的線型共振腔、波長可調式光纖雷射。
為了製作波長可調光纖光柵，提出兩種方法分別是使用可繞式材料與熱熔膠材料，在論文中說明比較它們的優缺點。其中使用可撓式材料方式的波長可調光纖光柵其可調範圍最大可達22.4 nm，以及微調解析度只有0.6 nm，所以在本論文後續皆選擇此種方式來架構波長可調光纖雷射。
線型共振腔波長可調光纖雷射在本篇論文實現兩種架構，第一種架構使用1×2 光纖耦合器搭配上兩根可調式光纖光柵，可調範圍涵蓋1534.96 nm至1566.0 nm之C 頻帶；利用相同概念可延伸至L 頻帶，一樣使用1×2 光纖耦合器搭配兩根波長可調式光纖光柵，可調範圍涵蓋1565.6 nm至1599.12 nm。第二種架構使用1×4 的光開關，加上四根波長可調光纖光柵，其中利用光開關做分流來涵蓋C+L 頻帶，也利用兩段增益光纖於L 頻帶使得到較高功率之光纖雷射輸出，最後整體波長可調範圍達71.58 nm，即從1528.8 nm至1600.38 nm幾乎涵蓋C+ L 頻帶。在室溫下整個波長可調頻譜之雷射功率最低為3.61 dBm，最高為6.95 dBm。對於不同波長之光纖雷射在-10°C至60°C的溫度變異，量測到的溫度係數皆為0.047 nm/°C且相當線性。於60°C的烤箱條件下持續12小時前後，其線型共振腔光纖雷射功率變動量低於±0.07 dB。

Nowadays, the bandwidth requirement for wavelength division multiplexing (WDM) system is very crucial. A tunable laser could play a role as back-up light source for individual WDM lasers, as well as a measured light source for equipments and components testing. In this thesis, C, L and C+L band tunable fiber lasers based on tunable fiber Bragg gratings (TFBGs) were investigated. It has the merits of cheaper and more flexible than most of the commercial products.
Here, two materials were utilized for realizing tunable FBGs and linear cavity fiber laser. There are hot-melt adhesive material and flexible material, respectively. The flexible material is the better one to make tunable FBG achieve a maximum tuning range of 22.4 nm with a fine-tuning resolution of 0.6 nm. The detail for parameters design and measurement are also addressed in later chapter.
Two schemes for linear cavity tunable fiber lasers are proposed in this thesis. The first scheme employs an 1×2 optical fiber coupler integrated two TFBGs, the wavelength tunable laser for C band ranges from 1534.96 nm to 1566.0 nm. The same concept can also be applied to L-band ranges from 1565.6 nm to 1599.12 nm. The second scheme employs an 1×4 optical switch (OSW) integrated four TFBGs. A segment of gain fiber is connected to the common port of the OSW. Two FBGs in port 1 and port 2, respectively, cover the C band; the other two FBGs in port 3 and port 4, respectively, cover the L band. Two segments of gain fiber are located in port 3 and port 4 to interact with the residual pump power for upgrade the lasing signal level. The whole tuning range is up to 71.58 nm (i.e., from 1528.8 nm to 1600.38 nm), covering almost the C + L band. At room temperature, the minimum and maximum output power are 3.61 dBm and 6.95 dBm, respectively, in this C+L band linear cavity fiber laser. The temperature coefficient from -10°C to 60°C has a constant value of 0.047 nm/°C for different wavelengths in-between 1534.96 nm and 1599.12 nm. At 60°C, the power variation of linear cavity fiber laser is less than ±0.07 dB before and after 12-hour burning.

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