雷射熱處理對光纖陣列連結器局部收縮的影響之研究

Study on the Effect of Laser Heat Treatment on Local Shrinkage in the Optical Fiber Connector

田東弘(Dong-Hung Tian)

指導教授 ： 陳仁浩

國立交通大學/工學院/機械工程系所/碩士(2018年)

摘要

光纖連結器的作用是要使光纖快速且精準的接合，降低接續時誤差導致能量的損失，可透過射出成型大量生產。然而，成型後內部分子鏈排序無法精準控制，外部產生局部收縮差異，造成精度誤差，使光纖連結器成型後的尺寸偏離設計值影響光訊號傳遞，過往研究大多以調整成型參數、冷卻速率等來控制收縮量，但能改善的精度有限。
非結晶高分子中存在著短距離結構，其比例與分佈會影響成品的機械與光學性質。本研究使用非結晶性材料PMMA，探討射出成型品的雷射熱處理效應對於非結晶材料的短距離結構與收的縮影響。
本研究使用非結晶性材料PMMA進行塑膠光纖連結器射出成型實驗，並利用IR雷射進行熱處理。同時，藉由靜態光散射系統量測熱處理前、後射出品散射量，探討射出成型品的短距離結構的分佈與變化，分析其與收縮量之關係。
研究結果顯示，隨著功率密度與照射時間長度的提升，射出品之收縮率會呈現正成長趨勢，其中又以改變功率密度更為顯著，但無法獨自調整各區域間尺寸，實現各區域收縮率均一化。經過雷射熱處理後，大部分功率密度下皆可改變短距離結構，使散射光強度改變量銳減，推測材料內部因能量吸收使結構重組，但與收縮率改變量無明顯相關性。
本研究透過靜態光散射量測法，確實檢測到非結晶性高分子成型品內的短距離結構，並透過雷射熱處理改變射出品內部的短距離結構，可以作為未來進一步改善非結晶性高分子成型品的均勻性和成型精度的參考。

關鍵字

雷射熱處理 ； 非結晶性高分子 ； 短距離結構

並列摘要

Fiber connectors enable fast and accurate connections for optical fibers then reducing the energy loss caused by connection errors. Such connectors can be formed via injection molding. However, molecular chain cannot be precisely controlled during this process, which results in shrinkage differences and fiber tolerance errors. Consequently, the dimensions of the optical fiber connector can deviate from the original design and affect optical signal transmission. In previous studies, this shrinkage was regulated by adjusting the parameters and cooling rate; however, the improvement in precision was limited.
The scale and ratio of the short-range structure of amorphous polymers are important as they affect the mechanical and optical properties of the optical fiber connector. This study investigated the effects of laser heat treatment on the short-range structure inside a molded polymethyl methacrylate (PMMA) fiber connector. The optical fiber connector was fabricated via injection molding and then heat treated using an infrared laser. Static light scattering was used to measure the scattering intensity both before and after the heat treatment. Furthermore, the distribution and change of the short-range structure were compared to analyze the correlation between the short-range structure and local shrinkage.
The results showed that the shrinkage increased with increasing power density and irradiation time, and energy change was the most influential factor on shrinkage. However, adjusting the dimension of each area and homogenizing the shrinkage at each location was difficult. As the scattering intensity variation can change most power densities after the laser heat treatment, it is assumed that the internal material structure is reorganized due to energy absorption. However, no correlation was observed between shrinkage variation and scattering intensity.
This study demonstrated that the short-range structure of an amorphous molded PMMA component can be detected using static light scattering, and laser heat treatment can reduce the order structure inside the molded PMMA component. In the future, this study can be used as a reference to improve the uniformity and molding accuracy of amorphous polymer molded components.

並列關鍵字

Laser heat treatment ； Amorphous ； Short-rang structure

參考文獻

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