Packaging of long wavelength sources coupled to single-mode fiber remains one of the most important impediments to the introduction of low cost reliable source components into the local loop. Recently, uptapered fibers have been developed1 to achieve self-aligned beam expansion for a variety of applications, including fiber to fiber connections2 and coupling to lasers.3 An uptapered fiber consists of a standard single-mode fiber which is tapered up at one end so that the lowest-order mode passes losslessly from one section to the other. This work examines for the first time, we believe, the coupling of uptapered fibers to LEDs and extends previously published work on coupling uptapered fibers to lasers.3 In addition, a practical packaging method using uptapered fibers has been developed. The reduced lateral alignment sensitivity of uptapered fibers dramatically aids in initial coupling, therefore, reducing cost, and in improving long-term stability, which increases reliability.
© 1989 Optical Society of AmericaPDF Article