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Message: What is so special about POET’s waveguide filtering capability?

Just to add a little clarity re Suresh's comment: The same thing is true here: the lasers move.

The lasers do not physically move but the wavelength that the laser emits does move. It shifts based on the operating temperature and characteristics of the laser. Thus it is important that the flat box shape that is represented as the received wavelength have a wide enough range and spacing so that wavelength drift will still be received as the intended channel.

I would also like to add that there are many standards for 400G. But the two that POET is building covers the reach and the advantages that industry requires for data center applications that a Tier 1 customer would want.

THE 400G OVERVIEW

IEEE P802.3bs

 

The table below describes the IEEE Application Acronyms for 400G.

Please note that for formfactor QSFP-DD and OSFP the electrical interface will always operate at 8 x 50G (PAM4).

acronym

optical lanes

speed per optical lane

distance

wavelength

comment

DR

1

100G (PAM4)

500m

1310nm

used for 100G QSFP28 with single lambda working at 112G

DR4

4

100G (PAM4)

500m

1310nm

PSM, breakout with DR possible

DR4+

4

100G (PAM4)

2km

1310nm

PSM, DR4+ is not a IEEE acronym

FR4

4

100G (PAM4)

2km

1270, 1290, 1310, 1330nm

CWDM, no breakout mode

FR8

8

50G (PAM4)

2km

1270, 1290, 1310, 1330nm

June 2018: haven't seen on any QSFP-DD and OSFP roadmap

LR4

4

100G (PAM4)

10km

1295, 1300, 1305, 1310nm

no breakout mode

LR8

8

50G (PAM4)

10km

1273, 1277, 1282, 1286, 1295, 1300, 1304, 1309nm

June 2018: haven't seen on any QSFP-DD and OSFP roadmap

SR4 2xBIDI

8

50G (PAM4)

100m

850/910nm

400G with MPO12 (instead MPO16). MPO12 is used for 100G SR4 and 40G SR4

SR8

8

50G (PAM4)

100m

850nm

MPO16 required

Abbreviations:

PSM = Parallel Singlemode
CWDM = Coarse Wavelength Division Multiplex

 

https://www.flexoptix.net/en/blog/2018/06/the-400g-overview/

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