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Browse Prior Art Database

Fiber-Optic Modal Bandwidth Measurement Tool

IP.com Disclosure Number: IPCOM000119619D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 63K

Publishing Venue

IBM

Related People

Boerstler, DW: AUTHOR

Abstract

Disclosed is a technique for determining the modal bandwidth of a fiber-optic link without the need of sophisticated bandwidth measurement tools and techniques.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 53% of the total text.

Fiber-Optic Modal Bandwidth Measurement Tool

      Disclosed is a technique for determining the modal
bandwidth of a fiber-optic link without the need of sophisticated
bandwidth measurement tools and techniques.

      The technique (see the figure) requires a series connection of
a transmitter card 12, the link under test 14, an optical attenuator
16, a receiver card 18, and a counter 20.  An optical power meter is
also required.

      The components are described as follows:
-    The transmitter card 12 contains an encoder 22 with its input
strapped to a known test data pattern, a serializer 24 to accomplish
the parallel-to-serial conversion, and a fiber-optic transmitter 26
to convert the electrical signal to an optical signal.  The
transmitter's center wavelength and spectral width are known.
-    The link 14 under test is the link for which the modal bandwidth
must be ascertained.  The length of this link must be known.
-    The optical attenuator 16 reduces the optical signal level of
the link under test.
-    The receiver card 18 contains an optical receiver 28 to convert
the optical signal to an electrical signal, a deserializer 30 to
extract the clock, retime the data, and accomplish the
serial-to-parallel conversion, and a decoder 32 which checks for the
test data pattern and raises an error line for each error.
-    The counter 20 is connected to the error line and counts the
number of errors over some period of time.
-    The op...