RE: 10GBase-LR/LW Supporting 1550 nm
Jugnu:
I do not see nay issue from the reciver sensitivity, it is mostly quite
broad.
However, I have been come to know that, if we use 1550 test equipment
to evaluate
1310nm modules, there is one thing to be taken into account. The
bandwidth of the test
equipment needs to be less than 8GHz so that the relaxiation oscllation
of
the 1330nm optical waveform is filtered. Otherwise, it may cause problem
like
bit error .BER..
Rao
Solinet Systems
-----Original Message-----
From: Jugnu Ojha [mailto:jojha@xxxxxxxxxxxxxxxxxxx]
Sent: Thursday, April 12, 2001 1:49 PM
To: 'Ali Ghiasi'
Cc: 'Ali Ghiasi'; Serial
Subject: 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@xxxxxxxxxxxx]
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@xxxxxxxxxxxxx]
> Sent: Wednesday, April 11, 2001 7:01 PM
> To: Serial; stds-802-3-hssg-serialpmd@xxxxxxxx
> 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.