Dear Participants,
My message to Ali contained some factual errors that were
unintended and this was brought to my attention.
First off, my statement that the "Task Force chose to
move forward with a draft development..." was inaccurate. It
should have been "Task Force discussed a
plan to move forward with a draft
development..." There was no Task Force vote or decision on this
subject.
And as Arash noted, he volunteered to produce a PAM draft. I
apologize for failing to capture that point.
As discussed in Orlando, to achieve our schedule, it will be
helpful to have a draft clause for any baseline proposal that may
be adopted. If you wish to provide a draft clause for any
particular proposal, I would suggest attending the upcoming SMF ad
hoc and communicating to the chair (Pete Anslow) or you may
contact me directly.
Thank you,
Dan Dove
Chair IEEE P802.3bm
On 3/25/13 12:12 PM, Daniel Dove wrote:
Hi Ali,
Thank you for sharing your opinion.
The Task Force chose to move forward with a draft development
for both a PSM4 (Pete) and CWDM (Petar) doing the work, on the
assumption that one of these approaches *may* see sufficient
consensus to achieve a baseline proposal adoption. PSM4 was
highest in the straw polling, and CWDM was next highest.
Anyone who has confidence that they can achieve consensus on an
alternative baseline proposal is asked to also produce a draft
clause so that we can leave the May meeting with a full draft
set of clauses to move forward with into Task Force review.
Clearly, LR4 and ER4 will be choices available to the industry
in a 4x25 CAUI-4 based solution. Whether or not they are
sufficient to address broad market needs over time will be
defined by the Task Force.
Regards,
Dan Dove
Chair, IEEE P802.3bm
On 3/25/13 11:39 AM, Ali Ghiasi
wrote:
Dear Dan
We had a very productive OFC meeting and hope you as well
had a productive IEEE meeting!
There were two interesting announcement at OFC with
implication to .bm SMF objective:
Where
Finisar CFP2 100Gbase-LR4 PD< 7 W based on DFB DML
Where
Cisco announces 100Gbase-LR4 CPAK OFC demo based on Silicon
Photonics with PD < 5.5 W
Above 100GBase-LR4 products in live demo during OFC-2013
have power dissipation lower than power quoted in some of the
IEEE presentations.
PSM4 does not offer cost advantage of 0.23-0.13 as was
illustrated with PAM solution
It is clear that in the .bm group the solution based on
serial 100 Gb/s with best economic and cost advantage
require more time to converge to a baseline proposal than we
have in the bm group. IEEE already has the Cadillac solution
the 100Gbase-LR4 and I believe nearly everyone in our task
force would agree the ultimate solution is serial 100 Gb/s
and something we have to define in the 400 GbE, but we may
disagree on the timing. If we can't agree to define the
ultimate solution now, do we wait or do we define something
between the Cadillac and the ultimate solution that may only
have short term market potential ?
I would definitely support both CWDM and PSM4 as part of an
MSA definition.
Thanks,
Ali
On Mar 25, 2013, at 10:16 AM, Daniel Dove wrote:
Hi Brad,
Thanks for bringing this up.
All, when producing questions on a presentation please
be attentive to the fact that we participate on an
individual basis and frame your questions to the
individual, not their employer or affiliation.
In the same manner, if someone asks you a question
directed to your employer or it's business, or any
other business for which you may have information that
is proprietary, do not feel obligated to respond.
Regards,
Dan Dove
Chair, IEEE P802.3bm
On 3/25/13 9:57 AM, Brad
Booth wrote:
I’m
a bit concerned about this line of questioning
and some of what I noticed happening at last
week’s meeting (at least the portion I was able
to attend).
There
seems to be a lot of focus on vendor-specific
implementations which then trends into the realm
of cost comparison, NDAs, and opinions on
technical viability.
The
goal of the task force is to develop a standard
written such that it is not dependent on any
implementations, but rather that it enables
multiple, interoperable, compliant
implementations.
Is
it possible to put the relative cost comparison
and vendor-specific implementation information
aside and focus on the market requirements and
technical merits of each proposal?
Thanks,
Brad
Dear all,
As a follow-up on yesterday’s discussion I am
summarizing here questions to the presentation
http://www.ieee802.org/3/bm/public/mar13/welch_01_0313_optx.pdf
Some of the questions I was able to ask during the
Q&A time, while some of them were left
unanswered or even not asked due to request of the
Chair to move the rest of the discussion offline.
Following Chair’s suggestion I am writing down all
the questions I was planning to ask here in the
Reflector. I do believe that it is important for
people on the floor to get an unbiased view on
advantages and disadvantages of various proposals
as well as on technologies behind them to cast a
balanced educated vote.
The answer on the first question is crucial. I
would have had no further questions if the answer
would have been “Yes”. However the answer was
“No”. Correspondingly I feel obligated to present
here all the questions numbered consecutively with
the page number in the presentation listed for the
reference.
Page 1
Question 1
Do you agree or do you not, “yes” or “no” would
suffice, that “Si Photonics” in the title of your
presentation means “Luxtera Si Photonics
technology” and, correspondingly, the numbers and
statements presented are related to advantages and
disadvantages that Luxtera technology has in
trying to reach performance required by different
baseline proposals?
Page 2
Question 2
This page represents the strategy for comparative
analysis of link budget, power, assembly and cost
for CWDM, PSM4 and LR4. Depending on how this
strategy is formulated a substantially different
set of conclusions can be reached.
It is stated that for power estimate the “fully
integrated silicon photonics solution using 28nm
CMOS node” is being used. Does “full integration”
means CMOS circuits and optical devices located
side-by-side on the same silicon die?
Question 3
What is the level of maturity of this “fully
integrated silicon photonics 28nm CMOS technology”
– a) is it in development, b) is it fully
qualified or, by any chance, c) does Luxtera
already have transceiver (not AOC) products
shipped today in volumes with this technology
node?
Question 4
In this page you mention “existing silicon
photonics technologies”. Which existing silicon
photonics technologies are you considering: a)
Luxtera technology exercised in 130nm node at
Freescale, b) Luxtera 28nm technology mentioned
above, c) any other Luxtera technology not
mentioned or d) Si Photonics technologies of other
companies?
Question 5
If the answer to Q4 is “all of the above”, what
are the sources of your information and what is
the approach you are using in assessing the
non-Luxtera Si Photonics technologies?
Page 4
Question 6
Which technology version of Luxtera Si Photonics
technology the performance numbers of WDM mux and
Demux correspond to – a) the 130nm Freescale or b)
“fully integrated silicon photonics 28nm CMOS
node”?
Question 7
How different is the interleaver presented on the
right bottom corner of this page from the one
reported in T.Pinquet et al, Proc. of SPIE Vol.
6898, 689805, (2008) with 2.6dB insertion loss?
Question 8
Are you aware of other reports on low-loss and
passive (no tuning power required) WDM filters
demonstrated in a number of non-Luxtera Si
Photonics technologies?
Question 9
For example, are you aware of several
presentations presented in the past at this IEEE
802.3bm as well as in the 100G Study Group
meetings on WDM filters based on non-Luxtera Si
Photonics technologies that have less than 3dB
insertion loss:
pages 9 and 10 in
gill_01b_1112_optx.pdf
page 12 in
vlasov_01a_1112_optx.pdf
page 6 in martin_01_0712_optx.pdf
page 4 in vlasov_01_0312_NG100GOPTX.pdf ?
Question 10
Are you aware that of these WDM devices listed in
Q9 (in addition to many other silicon photonics
WDM demonstrations currently in the public domain)
NONE are relying on active thermal tuning of the
WDM components phase and hence do not contribute
to the total dissipated power as it is
demonstrated, for example, on page 10 of
gill_01b_1112_optx.pdf ?
Question 11
Are you aware that all of these measured results
listed in Q9 are obtained on chips fabricated on a
high-volume non-Luxtera Si Photonics technology
platforms in Kotura or IBM?
Question 12
Do you agree that the necessity to burn a total
of 1.8W of power for tuning of WDM components as
suggested in page 4 is not a generic problem with
all Si Photonics technologies, but rather,
perhaps, a problem with one of Luxtera’s Si
Photonics technologies? Which one?
Page 5
Question 13
Does the “PSM4”, “CWDM” and “LR4” on the top of
each column have any relation to corresponding
baseline proposals as it was presented at the
latest meetings of 802.3bm (anderson_01a_0313_optx.pdf and
vlasov_01a_0313_optx.pdf,)?
Question 14
The usual approach to calculate the optical power
link budget that 802.3 has followed for many years
is to calculate the channel insertion loss between
TP2 and TP3 and add the TDP penalty. For all IEEE
standards this link budget does not include
insertion loss of the transmitter or receiver.
These latter numbers are left for vendors to
resolve and are not a part of any standard.
If the Q13 answer is “yes” then do you agree that
the link budget calculations should follow the
usual definition as channel insertion loss plus
TDP penalty for 500m channel reach as presented
for all PMD baseline proposals so far?
Question 15
If the answer to Q13 is “yes” and the “CWDM”
column represent an attempt to build a channel
insertion loss budget based on the 100GBASE-CWDM
baseline proposal (vlasov_01_0113_optx
or
vlasov_01a_0313_optx) , why 2km option is
used on line 4 with additional 0.75dB insertion
loss, while the objective of both the 802.3bm TF
and the baseline CWDM proposal is the reach up to
500m?
Question 16
If the answer to Q13 is “no” this means that
columns “CWDM” does not refer to a specific
baseline proposal. It is possible then to assume
that the table represents an attempt to fold
module insertion loss into the link budget and
compare to other solutions.
In this case, if the answer to Q4 is “all of the
above” and the answer to Q9 is “Yes” then why
additional 3dB+3dB=6dB insertion loss due to MUX
and DMUX is included for “CWDM” column since it is
a problem specific only to one or all of Luxtera
technologies in yielding low loss WDM, and this
generalization is not applicable to all possible
non-Luxtera Si Photonics technologies?
Page 6
Question 17
If the answer to Q13 is “yes” and columns “PSM4”
and “CWDM” correspond to PSM4 and CWDM baseline
proposals as presented in anderson_01a_0313_optx.pdf and
vlasov_01a_0313_optx.pdf, correspondingly,
then the bottom line of the table representing
“per baseline proposal (aggregate)” corresponds to
maximum channel insertion loss. Correspondingly,
for the baseline PSM4 this should be 3.26dB and
for the baseline CWDM should be 4dB.
Correspondingly, the difference in channel
insertion loss between PSM4 and CWDM baseline
proposals should be 0.74dB, not 7dB. With maximum
TDP budgeted differently (for baseline PSM4 as
3.8dB and for baseline CWDM as 2.2dB) the total
power link budget for maximum TDP is actually
7.06dB for PSM4 and 6.2dB for CWDM. Do you agree?
Page 8
Question 18
If the answer to Q1 is “Yes” there are no comments
related to pages 8, 9, 10, and 11 since it solely
represents numbers for Luxtera “fully integrated
silicon photonics solution using 28nm (or better)
CMOS node.” The maturity level of this technology
is already answered in Q3. If the answer to Q1 is
“No” – then there is a question: Which version of
non-Luxtera Si Photonics technology (and from
which company) is used to fill out the columns
“CWDM” and “LR4” in pages 8, 9, 10, and 11?
Page 12
Question 19
There is a subnote “Achilles heel of CWDM”. Which
non-Luxtera Si Photonics technologies are having
these problems?
Page 13
Question 20
Which non-Luxtera Si Photonics technologies are
having these problems?
For example edge coupling technologies are, in
fact, widely used for edge emitting lasers iii-V
PICs, etc. for many decades. Some of non-Luxtera
Si-Photonics technologies successfully using edge
coupling for volume products, like for example VOA
and other components from Kotura. It is, actually,
vertical grating couplers that Luxtera technology
is using that is a relatively new and to my
knowledge unique approach for coupling light in
and out of the PIC.
In general, it is possible to imagine that
non-Luxtera Si Photonics technologies utilizing
edge coupling might not necessarily suffer from
violation of CMOS design rules, do not require
CMOS post-processing (precision dice/polish), can
enable easy fiber attach, and do not require large
area for bonding to CMOS.
Question 21
If Luxtera Si Photonics technologies are being
used for comparison it would be good to know which
version of the technology a) 130nm Freescale or b)
“fully integrated silicon photonics solution using
28nm (or better) CMOS node” is being considered?
If it is a) then indeed millions of parts were
shipped and edge coupling was not in production
and is only theoretically known. If it is b) then
it is necessary to refer to the answer to Q3 and
apply it here with respect to the statement
“millions of grating couplers already shipped”.
Question 22
What the source of the information that
non-Luxtera Si Photonics technologies using edge
coupling are having a problem of “prohibiting chip
on board cost reductions”.?
Question 23
What the source of this information that
non-Luxtera Si Photonics technologies that are
using edge coupling are having to rely on
“polarization maintaining fiber”?
Page 14
Question 24
If the answer to Q1 is “No” and the statements on
this page also include comments on non-Luxtera Si
Photonics technologies, then the word
“theoretically” should be removed since numerous
feasibility demonstrations have been presented in
the open public domain showing monolithically
integrated WDM mux, Demux, photodetectors,
modulators, etc. that can be found for example in
the proceedings of the OFC from 2007 to 2013. I
can easily provide over 50 recent references upon
request.
Page 15
Question 25
If the answer to Q1 is “No” and the statement on
this page 14 “Insufficient technology maturity to
reasonably project costs/yields” also includes
comments on non-Luxtera Si Photonics technologies,
then I would insist on rephrasing the statement to
“Insufficient information that Luxtera has on
technology maturity to reasonably project
costs/yields”.
Page 16
It is a critical page in the presentation as it
compares module costs for various implementations.
Question 26
If the answer to Q1 is “Yes” then don’t the
statements in this comparison refer to problems
specific to Luxtera Si Photonics technologies, and
as such this comparison illustrates that Luxtera
Si Photonics technologies could not provide CWDM
modules in a cost-effective manner.
Question 27
If the answer to Q1 is “No” then the statements in
this comparison implies generalization of problems
specific to Luxtera technologies to all other
non-Luxtera Si Photonics technologies. In this
case I would ask which non-Luxtera technology is
used for this comparison and what the source of
this information is. I would also suggest to take
into account three independent relative cost
analysis studies presented in
martin_02_0912_optx.pdf, shen_01a_0313_smf and in vlasov_01a_1112_optx.
Page 17
Statements on this page either refer to Luxtera Si
Photonics Technologies (if the answer to Q1 is
“Yes”) or (if the answer to Q1 is “No”) it is
required to provide additional information as
mentioned in all related questions above.
Sincerely
yours
Yurii
Vlasov
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