臺灣博碩士論文加值系統

在本篇論文中, 我們提出一個廣泛的方式, 用來分析在非對稱的雷射光場
到單模態光纖的耦合時, 偏移誤差對耦合效率的影響. 我們利用此方法導
出兩種光耦合方式在最佳化的情形下, 在軸向, 橫向及角度方面所能容忍
的最大偏移量 ( 耦合效率仍大於 50%). 第一種方式使用旋轉對稱的透
鏡 , 而第二種方式則使用一種特殊的非旋轉對稱透鏡, 即微圓柱透鏡來
做光耦合.為了驗證我們以微圓柱透鏡的分析結果, 我們成功地自製不同
口徑的微圓柱透鏡, 並將之與單模態光纖結合形成一整合型的元件. 我們
利用此一元件量測出不同口徑的圓柱透鏡對光耦合量的影響, 並量測到雷
射在軸向及水平橫向上的偏移容忍度. 在此兩方面的容忍度相當大, 約
有 5微米. 由此實驗結果與理論結果的對照中, 我們發現利用微圓柱透鏡
來做雷射與光纖間的耦合時, 高效率的耦合和高容忍量可同時達到.

In this thesis, a general method of analyzing misalignment
tolerances of coupling light from an astigmatic laser diode to
a single-mode fiber is described. We apply the method to derive
the 3-dB tolerances caused by longitudinal, lateral, and
angular misalignments in the optimal conditions for two kinds
of coupling schemes. One is by the use of a rotationally
symmetric optical system, and the other by a rod lens which is
a special case of utilizing a rotationally asymmetric optical
system. To verify the dependence of coupling efficiency upon
the rod radius, rod lenses with various radii are fabricated
and combined with a single-mode fiber array to form an
integrated coupling device for optical coupling. The 3dB
tolerances are also measured. The longitudinal tolerance and
the lateral tolerance in the horizontal direction of the laser
are about 5 micron, which are relatively large. From the
experiment results, both high efficiency and large tolerances
can be achieved by using a rod lens as coupling optics.