2004-08-012024-05-15https://scholars.lib.ntu.edu.tw/handle/123456789/662471摘要：以光纖作為傳輸介質的光波通訊，是通訊網路上的一個很重要特徵，因為光纖具有低損耗、寬頻帶的傳輸優點。而光纖光柵可視為光通訊上一個重要的窄頻帶的反射濾波器(narrow-band reflection filter)，當入射光波長符合布拉格條件(Bragg condition)，光纖光柵的反射係數可以接近100 %，穿透係數可小於負30dB。 但光纖光柵有嚴重波長熱飄移的問題，100℃之溫度變化，會造成布拉格反射中心波長1nm以上的飄移。本計畫將針對固定式熱補償光纖光柵及可調式光柵遭遇到溫度變化所產生之波長飄移，以及如何對此一現象作一補償的方法，做一基礎性的研究及研製雛型結構，並利用有限元素軟體及理論分析，設計新式熱補償機構並將其加工成型，檢驗此機構的光柵波長飄移量是否滿足25GHz頻道間距要求。 計畫擬分兩年完成，兩年之工作內容包含(1)專利搜尋 (2)理論分析 (3)光柵結構模擬(4)以有限元素法進行波長飄移模擬 (5)結構最佳化設計 (6)雛型結構製造 (7)實驗量測與理論分析 (8)專利與論文之撰寫。同時亦將與加州大學Irvine校區電機系的Professor Henry<br> Abstract: Fiber Bragg grating (FBG) has recently been proved as an effective device in telecommunication because it can be used as a narrow-band reflection filter for add-drop usages. It has been demonstrated that the refection can be closed to 100% and the loss less than -30dB. However, there are always concerns about central wavelength shift due to temperature change. This is due to a thermal-mechanical characteristic of fiber and the structure on which the FBG is mounted. The averaged wavelength shift for a typical FBG without imposing any thermal compensation module is about 1nm at 100C temperature change. This shift is not allowed according to the regulation set by International Communication Union, ITU. As a result, effort must be done to keep the shift of the central wavelength as small as possible within the operation range. Moreover, in DWDM applications there is always a need to adjust the central wavelength during operation. Consequently, a tunable FBG module is essential in such applications. This research aims at making a thermally compensated FBG module that not only has athermal characteristics but also tunable. There are two goals to reached for this two-year research: (a) First Year Goal: Develop a structure on which the FBG mounted can have as less shift on central wavelength as possible. The goal is to meeting the 25GHz requirement, i.e., the wavelength shift is less than ±15pm for temperature between –40 to +85C. The work will include patent search, structural design, theoretical and numerical analysis for the optimal design of the structure, prototyping, experiment and evaluation, and patent writing. Moreover, we will team up with Professor Henry P. Lee of University of California of Irvine (UCI). UCI team has very strong background in optical analysis of FBG and LPG. We have co-worked with them and co-authored a paper accepted by IEEE Journal of Lightwave Technology. This research will be a continuing work extended from my 6-month visit to them in 2003. (b) Second Year Goal: Develop a tunable FBG and also meet the requirement of 25GHz. The tunable range is to be larger than 2nm. We will try various driving ways such as, manual driving using screws, driving by PZT transducer or mini stepping motor. Moreover, effort will be made to write firmware on an EEPROM so that the whole module can be control by a micro-processor. In addition, we will also study the effect of different mechanical bonding and clamping on the long term reliability of the whole packaged structure. Further, we aim at having the size of the structure less than 60 mm in length.可調式光纖光柵中心波長熱補償頻道間距理論分析DWDMTunable Fiber GratingCentral WavelengthThermal CompensationChannel SpacingDWDM