RE: 10GBase-LR/LW Supporting 1550 nm
Hi Ali,
The numbers are indeed quite close. But there's still a difference of 0.5
to 1 dB. For a 1550 Tx talking to a 1300 Rx, in-line attenuators would
solve any overload problem. But what happens when you have a 1300 Tx
talking to a 1550 Rx? I assume BER suffers - this needs to be quantified.
Regards,
Jugnu
-----Original Message-----
From: Ali Ghiasi [mailto:aghiasi@broadcom.com]
Sent: Thursday, April 12, 2001 10:10 AM
To: Jugnu Ojha
Cc: 'Ali Ghiasi'; Serial
Subject: Re: 10GBase-LR/LW Supporting 1550 nm
Hi Jugnu
I looked at three manufactures of InGaAs Photodiode which are
suitable for 10 Gig Operation and the responsitivity are as the
following for 1300nm and 1550 nm:
1300 nm 1550 nm
mfg 1 0.9 0.8 A/W
mfg 2 0.8 0.85 A/W
mfg 3 0.95 1.0 A/W
Responsitivity between 1300 nm and 1550 is nearly identical.
Any overload need to be addressed similar to 1550 nm
case by adding in line attenuator, unless one build a
lower power version for SR.
Thanks,
Ali
Jugnu Ojha wrote:
>
> Ali,
>
> I think interop between 1310 and 1550 would be extremely useful. Does
> anybody have any precise numbers for responsivity in the two ranges? It
> would be advisable to quantify this and determine any impact on overload,
> BER, etc.
>
> Regards,
> Jugnu Ojha
> Caspian Networks
> (408)382-5213
>
> -----Original Message-----
> From: Ali Ghiasi [mailto:aghiasi@earthlink.net]
> Sent: Wednesday, April 11, 2001 7:01 PM
> To: Serial; stds-802-3-hssg-serialpmd@ieee.org
> Cc: Ali Ghiasi
> Subject: 10GBase-LR/LW Supporting 1550 nm
>
> Hi
>
> Last week during the serial PMD call I suggested possible need for
> Interoperability between 1550 and 1310 nm. I was asked to write a
> short description.
>
> MY intention was if you have a 1550 nm source assuming you met overload
> for the 1300 nm receiver you are allowed to operate with 10GBase-LR/LW
> over 10 Km. If we look at Table 52-13 the wavelength range currently
> specified from 1265-1355 nm. Without adding any burden we can
> define a second window around 1550 nm to allow use of 1550 nm lasers
> with 10GBase-LR/LW. InGaAs/InP detector sensitivity is nearly flat
> in this region and it may only require to specify dual wavelength AR
> coating, which is already very common.
>
> Thanks,
>
> Ali Ghiasi << File: Card for Ali Ghiasi >>
--
Ali Ghiasi
Broadcom Corp.