Fiber Optic Center will be at Anga Com - Schedule your meeting with a member of the FOC team now

    phone (800) IS-FIBER · (508) 992-6464

    Toggle Nav
    My Cart
    My Quote
    close
    Search

    Coupling a 125 or 200UM Core-Diameter Fiber Onto a Led Die

    by:
    FIBER & CABLE: Ask FOC Ask FOC
    Published: July 24, 2015

    ASKFOC_web2-

    QUESTION: I am interested in efficiently coupling a 125 or 200um core-diameter fiber onto an LED die. My understanding is that the coupling efficiency is limited by the NA and core diameter of the fiber in most circumstances. Is it possible to use a tapered fiber, e.g. starting at 1000um core and moving to 125 or 200 um core to increase the irradiance at the small diameter fiber side?

     

    ANSWER:

    Transmission light from the LED die into any fiber is controlled by both the core and NA as well as the NA of the light coming out of the source. Obviously, the larger the fiber NA and core the better the coupling efficiency. We’ve done a lot of work using LED dies in conjunction with 1000um POF fiber which is a perfect match. Due to most application requirements, we’ve been forced to develop methods of coupling to 200um fibers with a .37NA and .48NAs. Inexpensive tapers did not work unless they were very long which are very expensive. Also, tapers had to be manufactured with a gl/gl fiber of .22NA which defeat the purpose of the design criteria. The shorter the taper, the more severe the internal angle thus the coupling efficiency is very poor. This can be easily modeled by performing a ray trace on zemax. Here is what we’d recommend, assuming the power is fairly low, a plastic lens would be the most cost effective as well as having the best coupling efficiency.   There will be other issues that will have to be dealt with here related to the output pattern of the LED die.

    1. Oval or rectangular shape.

    2. Hot spots

    3. Cladding modes of the fiber.

    4. Fiber output, if the length is short will be very strange as well.

    In short, there are quite a few issues to consider and we are more than happy to put you in contact with someone to discuss further.

     

    ADDITIONAL CONTENT & RESOURCES:

     

    SM6AskFOCIcon  Answered by AskFOC Technical Team July 24, 2015

     

     

    Have a technical question for Fiber Optic Center?

    Please email your question to AskFOC@focenter.com and we will respond ASAP.

    In addition to replying, we will post your question and our answer here on focenter.com.  Everyone remains anonymous when we post so feel comfortable asking.  You can also search your question and others in our content search.

    About the Author
    FOC FAQ Fiber Optic Center has a team of technical experts and marketing strategists with decades of years in the field. This team contributes to the fiber, cable and specialty industries coverage through news, alerts, reports and general media information.
    Education Resources

     

    Light Brigade Certified Training

     

    About Fiber Optic Center, Inc.
    Fiber Optic Center, Inc., (FOC), is an international leader in distributing fiber optic components, equipment and supplies and has been helping customers make the best cable assemblies in the world for over two decades. Several areas of specialization and expertise, in which they are the industry leader, make them the preferred choice for many of the world’s fiber professionals. In these key technology areas, FOC is "at least as technical as the manufacturer" about the products they sell. Striving to "make the business part easy," they offer outstanding and personal customer service, low or no minimum purchase order values, and from-stock delivery on industry-leading products and technology. FOC is the industry connection to the most innovative optical products, technologies and technical experts who integrate their manufacturing knowledge and vast experience into customers' worldwide operations. @FiberOpticCntr

    For further information contact:
    Fiber Optic Center, Inc., 23 Centre Street, New Bedford, MA 02740-6322
    Toll Free in US: 800-IS-FIBER or 800-473-4237 . Direct 508-992-6464. Email: sales@focenter.com or fiberopticcenter@focenter.com

    For media contact:
    Kathleen Skelton, Director of Strategic Marketing, C: 617-803-3014 . E: kskelton@focenter.com
    Copyright Notice: Copyrights in all articles published on focenter.com are owned by Fiber Optic Center, Inc. (FOC) or other individuals or entities. No content on focenter.com may be reproduced, stored in a retrieval system, or transmitted in any form of by any means, electronic, mechanical, photocopying, recording, or otherwise, in whole or in part, without the prior written permission of Fiber Optic Center, Inc.