2013-01-012024-05-15https://scholars.lib.ntu.edu.tw/handle/123456789/665321摘要：近年來將半導體材料結合光纖光學已是一項新興的研究課題，半導體材料有著傳統光纖沒有的導電特性，高非線性係數，與中紅外光穿透頻寬，結合成熟的光纖光學，將可開啟新的應用層面，包含生化感測，飛彈導引，與自由空間光通訊等。本計劃為三年期計畫，第一年著重研製矽纖核光纖，包括預型體及高溫抽絲塔的製備。第二年量測其材料與光學特性，並探討光傳輸損耗的機制，第三年則進行優化矽核光纖並探討其應用。 我們利用自製垂直抽絲系統進行將多晶矽粉製備成矽核光纖，並使用微拉曼光譜及場發射穿透式電子顯微鏡，證實矽核光纖呈現單晶的特性(如下圖一、圖二)。微拉曼光譜結果顯示整條矽核光纖有均勻一致的優良材料特性。而光學傳播損耗的量測結果，發現在1520-1560奈米波長其平均損耗值約0.3-0.4 dB/cm，該值低於所有已知文獻的報導。 圖一(a)為正在抽絲階段的矽核光纖示意圖，利用顏色標示出不同區域。深灰色表示原始的多晶矽粉末；橘色表示液態的非晶矽；紅色表示正由非晶轉換及凝固到單晶的範圍；藍色表示固體的單晶矽；綠色表示石英纖殼。(b)為矽纖殼的微拉曼光譜圖，各曲線的顏色對應到(a)圖的顏色區域。 圖二(a)為矽核光纖剖面切片的穿透式電子顯微鏡圖。(b)為同一角度下的繞射晶格點，(a)及(b)圖皆說明矽核為[110]方向的單晶矽。 圖三(a)量測光學傳播損耗的架構示意圖；(b) 波長為1520-1560奈米的平均傳播損耗圖。 <br> Abstract: Recently the combination of semiconductor materials with fiber optics has become one of the emerging research topics. Semiconductor materials, when compared to the conventional optical fibers largely made from silica, have unique characteristics, such as good electric conductivity, high nonlinearity, and transparent in mid-infrared regimes. Such combination of semiconductor materials and fiber optics may lead to entirely new applications including bio-chemical sensing, infrared missile guidance seekers, and free space optical communication. In the first year, we fabricated silicon cored fibers by employing home-made preform and high temperature drawing tower. In the second year, we have been characterizing material and optical properties of the drawn silicon fibers, aiming at reducing propagation loss from the underlying mechanisms. In the third year, we will optimize silicon cored fibers and explore applications. By employing the home-made vertical drawing tower we made silicon cored fibers from polycrystalline silicon powder, and the crystallinity transformation from polycrystalline to single crystal was confirmed with micro-Raman spectra and transmission electron microscope. Measured results showed that uniform material properties were maintained along the entire length of silicon cored fibers. The measured propagation losses for wavelengths ranging from 1520 to 1560 nm were 0.3-0.4 dB/cm, the lowest yet to be reported in the literature. Figure 1. (a) Schematic diagram of internal states of silicon cored fiber during drawing process: dark gray part is the original silicon powder; orange part liquid amorphous silicon; red part transitional region between amorphous and single crystal phases; blue part single crystal silicon; green part silica cladding, (b) the micro-Raman spectra with each color of curve corresponding to the color region in Figure 1 (a). Figure 2. (a) TEM image, and (b) electron diffraction pattern of cross-sectional silicon cored fiber. Both (a) and (b) indicates silicon core is of [110] single crystal. Figure 3. (a) Setup for propagation loss measurement, (b) the measured propagation losses for wavelengths ranging from 1520 to 1560 nm.半導體材料光纖光學矽纖核光纖高溫抽絲塔光傳輸損耗垂直抽絲系統微拉曼光譜semiconductor materialsfiber opticssilicon core fibershigh temperature drawing towerpropagation lossmicro-Raman spectra