用於光纖光柵大範圍波長飄移之被動可調式溫度補償機構

The Passive and Adjustable Temperature Compensation Mechanism for Fiber Grating with Wide Range of Wavelength Drift

黃彥彰(Yen-Chang Huang)

指導教授 ： 單秋成

國立臺灣大學/工學院/機械工程學研究所/碩士(2014年)

https://doi.org/10.6342/NTU.2014.10449

摘要

光柵在光通訊上的應用相當廣泛，但由於它對外界溫度影響特別敏感，100°C之正溫度變化，會造成布拉格光柵反射中心波長有正1nm以上飄移，使得原本過濾出來的訊號脫離了國際通訊組織ITU的範疇，造成對訊號的誤判，若要將光纖光柵應用於濾波元件方面，波長飄移需要在0.4nm之內才行。
有鑑於一般溫度補償機構的優缺點，本文設計出一種改良型溫度補償機構，此機構由彎曲形狀的碳纖維複合材料板及內部為PE高分子材料之拘束元件所組成，將光纖膠合於彎曲複材板上，利用此機構的等效熱膨脹性質對光纖光柵施予適當的軸向負應變，使光纖光柵反射波長受溫度變化而產生的飄移量被抵銷掉，完成溫度補償。藉由有限元素法模擬，我們可以分析出不同幾何形狀或疊層方式的複材板及不同幾何形狀或材料的拘束元件對機構補償能力的影響趨勢。
而本機構的第一特點為「補償量可調性」，不需要取下光纖即可單純藉由改變拘束元件的寬度來即時調整機構對光纖光柵的波長飄移補償能力，對FBG可以達到約0.1pm/°C的補償效果；第二特點為「大範圍波長飄移補償」，由特定的複材板及拘束元件組合，此機構有能力對波長飄移量大的光纖光柵或光路進行溫度補償，單就FBG波長飄移值來看補償後可達到約-70pm/°C。此機構的補償再現性高、客製化設計彈性高、製作成本低、體積小。
本文會針對此補償機構的依序從設計理念、有限元素模型設計方法、機構製作流程、溫度補償實驗結果的比較與討論、至此機構在未來可以如何改善及如何針對特殊光柵作進階應用。

關鍵字

光纖光柵 ； 溫度補償 ； 複合材料 ； 可調整性 ； 大範圍

並列摘要

The grating is quite extensive in the optical communication applications, but it is particularly sensitive because the outside temperature. The 100°C temperature change will cause Bragg grating center wavelength drift than 1nm, making an already filtered out of the signal away from the international communications organization(ITU)'s areas, causing false signals. To be applied to FBG filter components, the wavelength drift within 0.4nm of the need for the job.
In view of the advantages and disadvantages of temperature compensation mechanisms, the paper design an improved temperature compensation mechanism which consists of a curved shape of the carbon fiber composite panels and PE polymer for the restraint’s materials.The grating is glued to the curved Composite panel. Using the equivalent thermal expansion properties of this mechanism, the mechanism lends to the fiber grating a appropriate negative axial strain, so that the amount of FBG wavelength drift produced by temperature changes was offset lost, completing the temperature compensation. By finite element method (FEM) simulations, we can analyze the different geometric shapes or laminated direction of composite panels and the different geometric shapes or materials of restraints will make what influence about the ability to compensate.
The first feature of this mechanism is "adjustable amount of compensation," . Do not need to remove the fiber away. Only by varying the width of the restraint to immediately adjust the compensation ability of the FBG can reach about 0.1pm/°C or less. The second feature of this mechanism is "a wide range of wavelength drift compensation". By a specific combination of the restraints and composite panels, this mechanism has a large capacity for wavelength drift or optical fiber grating temperature compensation. Compensate for the high reproducibility of this mechanism, high flexibility for custom design, low production cost, and small size.
This article will talk about this compensation mechanism for the design concept, the finite element model design, the process of making the mechanism, temperature compensation comparison and discussion of experimental results, and how they can be improved for advanced applications for special grating.

並列關鍵字

Optical fiber grating ； Temperature compensation ； Composite ； Adjustable ； Wide range

參考文獻

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