Appeal No. 2004-2153
Application No. 09/923,510
multiplexing (WDM).” Column 3, line 50+ of Willebrand also
highlights the use of erbium doped fiber amplifiers (ERDAs) and
expressly notes that the broad band amplification of ERDAs around
a 1.55 um fundamental frequency allows the ERDAs to be integrated
into systems using wavelength division multiplexing (WDM),
resulting in the ability to communicate separate information at
different wavelengths simultaneously in a single optical fiber
and avoiding the need for electro-optical conversions. Columns 4
and 5 of Willebrand describe additional “important improvements”
in the optical communication network therein resulting from the
use of ERDAs, e.g., allowing operation of an optical
communication network with free-space links at a fundamental
wavelength which is compatible with or approximately equal to the
fundamental wavelength typically used in long-haul optical fiber
communication systems and allowing the operation of free-space
links at laser wavelengths which are safer to human eyesight but
with sufficient link power margin to avoid many of the adverse
influences of atmospheric attenuation and divergence.
Appellants argue, and we strongly agree, that despite all
the examiner’s comments, it is clear that Willebrand purposefully
-6-
Page: Previous 1 2 3 4 5 6 7 8 9 10 Next
Last modified: November 3, 2007