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Question? 1300nm WWDM channel width

To all:

I have been trying to get some feedback on the channel width of the 1300nm
WWDM system.   As I currently understand the specifications, the bandwidth
of an individual wavelength channel is 11.4nm (spec of * 5.7nm).  At these
laser wavelengths, both DFBs and VCSELs have a temperature coefficient of
0.1nm/*C.  In order to achieve a final transceiver temperature specification
of 0-70*C, the lasers must have a slightly higher temperature range.  To be
safe, I would recommend a range of (-5) to 95*C.  With this range, the
wavelength drift will account for 10nm of the channel bandwidth, leaving
only 1.4nm for the tolerance of the laser fabrication.  The feedback I have
received from several laser vendors is, this will be very difficult,
resulting in low yields and increased costs for both DFBs and especially new
1300nm VCSELs.  

I would like to recommend that this specification be increased to at least
14nm (spec of * 7.0nm).  With a 24.5nm channel spacing, this will still
provide plenty of room for a relatively simply filter.  

I would like to get some feedback and response to this recommendation.

Eric Grann
Chief Technical Officer
Blaze Network Products