6
Figure 4. Optical Power Budget at BOL versus Fiber Optic Cable
Length.
OPTICAL POWER BUDGET (dB)
4.0
14
0
FIBER OPTIC CABLE LENGTH (km)
0.5 1.5 2.0 2.5
12
10
8
6
4
3.5
2
1.0 3.00.15
AFBR-5103Z, 62.5/125 µm
AFBR-5103Z,
50/125 µm
Application Information
The Applications Engineering group in the Avago Tech-
nologies Optical Communication Division is available to
assist you with the technical under standing and design
trade-o s associated with these trans ceivers. You can
contact them through your Avago Technologies sales
representative.
The following information is provided to answer some
of the most common questions about the use of these
parts.
Transceiver Optical Power Budget versus Link Length
Optical Power Budget (OPB) is the available optical
power for a ber optic link to accommodate ber cable
losses plus losses due to in-line connectors, splices,
optical switches, and to provide margin for link aging
and unplanned losses due to cable plant recon guration
or repair.
Figure 4 illustrates the pre dicted OPB associated with the
transceiver series speci ed in this data sheet at the Be-
ginning of Life (BOL). These curves represent the attenu-
ation and chromatic plus modal dispersion losses associ-
ated with the 62.5/125 μm and 50/125 μm ber cables
only. The area under the curves represents the remaining
OPB at any link length, which is available for overcoming
non- ber cable related losses.
Avago technologies’ LED technol ogy has produced 1300
nm LED devices with lower aging characteristics than
normally associated with these technologies in the in-
dustry. The industry conven tion is 1.5 dB aging for 1300
nm LEDs. The Avago Technologies 1300 nm LEDs will
experience less than 1 dB of aging over normal com mer-
cial equip ment mission life periods. Contact your Avago
Technologies sales repre sentative for additional details.
Figure 4 was generated with an Avago Technologies’
ber optic link model containing the current industry
conventions for ber cable speci cations and the FDDI
PMD and LCF-PMD optical parameters. These parameters
are re ected in the guaranteed performance of the trans-
ceiver speci cations in this data sheet. This same model
has been used extensively in the ANSI and IEEE commit-
tees, including the ANSI X3T9.5 committee, to establish
the optical performance require ments for various ber
optic interface standards. The cable parameters used
come from the ISO/IEC JTC1/SC 25/WG3 Generic Cabling
for Customer Premises per DIS 11801 docu ment and the
EIA/TIA-568-A Commercial Building Telecom munications
Cabling Standard per SP-2840.
Transceiver Signaling Operating Rate Range and BER
Performance
For purposes of de nition, the symbol (Baud) rate,
also called signaling rate, is the reciprocal of the short-
est symbol time. Data rate (bits/sec) is the sym bol rate
divided by the encoding factor used to encode the data
(symbols/bit).
When used in FDDI and ATM 100 Mbps applications the
performance of the 1300 nm transceivers is guaranteed
over the signaling rate of 10 MBd to 125 MBd to the
full conditions listed in individual product speci cation
tables.
The transceivers may be used for other applications at
signal ing rates outside of the 10 MBd to 125 MBd range
with some penalty in the link optical power budget
primarily caused by a reduction of receiver sensitivity.
Figure 5 gives an indication of the typical performance of
these 1300 nm products at di erent rates.
These transceivers can also be used for applications
which require di erent Bit Error Rate (BER) performance.
Figure 6 illustrates the typical trade-o between link BER
and the receivers input optical power level.
