Re: [802.3_NGEPON] FWM in O-band

[John Johnson <000007ff7d378f43-dmarc-request@xxxxxxxx>]

Derek,

Options for keeping all four US or DS channels or both in O-band are being considered by the task force, but at this time there is no consensus.  Most wavelength plans are proposing wide channel spacing, from 800GHz to 20nm, to keep laser and mux/demux costs low.  The higher launch power needed for PON is the biggest difference relative to point-to-point LWDM and CWDM links.  At least for the first wavelength pair, amplification is not an issue since cooled sources appear to have adequate output power. 

Regards,

John

On Fri, Jun 17, 2016 at 11:54 AM, <derek.cassidy@xxxxxx> wrote:

John,

 

Can I ask a question relating to the use of WDM in the O-Band, as an telecom operator I have never used WDM in the O-Band because it cannot be amplified without the need to regenerate the signal. I do believe that by extending the reach of optical channels in an O-Band setup and by incorporating as many channels are you not re-inventing an O-Band variant of the CWDM system? I am just asking this because the chance that FWM will interact with the existing optical channel plan is a possibility if the plan does not incorporate wide channel spacing. It is true that the O-Band (1260nm-1360nm) has a wider coverage than the C-Band (1530nm-1565nm) but the lack of amplification and high losses associated with the O-Band negated it as a possible candidate for multiple optical channel design, with exception to the CWDM method which only uses 5 channels within the O-Band spectrum.

 

Is there a view among the working group to look at the possibility of using WDM in the O-Band and if so then I think that yes FWM will be a factor. If the distance that being incorporated in the NGEPON design is smaller than the maximum allowable and does not exceed the optical power budget then the need to incorporate a channel plan with acceptable spacing will need to be agreed to avoid the FWM and other non-linear issues including receiver overload.

                                                                                                                                                                                                                                                        

Regards

 

Derek

 

 

 

From: John Johnson [mailto:000007ff7d378f43-dmarc-request@xxxxxxxx]
Sent: 17 June 2016 13:59
To: STDS-802-3-NGEPON@xxxxxxxxxxxxxxxxx
Subject: [802.3_NGEPON] FWM in O-band

 

Dear Colleagues,

 

At the close of the May meeting we discussed the possibility of FWM impairments for WDM in O-band.  If it is significant it could eliminate from consideration several possible wavelength plans and help consolidate consensus around the remaining plans.  A few people had volunteered to investigate this issue before the July meeting.  Is there any progress to report?  It would be great if this could be discussed at next week's consensus-building call.

 

Regards,

John