Sfp Modules - Alcatel 1850 TSS-320 Technical Handbook

3.5 SFP MODULES

(Refer to Figure 21. on page 60)
The SFP modules are the optical physical accesses necessary to operate the SDH unit (example
4P2G5SO, 8PSO...).
The following types of optical modules can be used:
• Black and White application:
– STM-1 SFP: S-1.1,L-1.1, L-1.2
– STM-16 SFP: S-16.1 w/DDM, I-16.1 w/DDM, L-16.1, L-16.2 w/DDM
– STM-16 multirate/multiformat: STM-16 ANY w/DDM
• CWDM application:
– STM-16 PIN (bronze) SFP: S-16.2 (1470 nm -> 1610 nm)
– STM-16 APD (silver) SFP: L-16.2 (1470 nm -> 1610 nm)
Each module contains on transmitter side an automatic optical output power control circuit, a laser driver
and a laser diode module.
The transmitter is based on an uncooled DFB laser.
The laser safety class for the complete integrated module is CLASS 1 according to IEC 60825 2001
Edition. It can manage command for TX disable and provides Tx Fault alarm.
Depending on the SFP type, the optical access is compatible with:
– single mode fibre (9/125 µm) or
– multi mode fibre (50/125 µm or 62.5/125 µm)
with standard LC optical connector.
TX Fault indicates a laser fault of some kind. The Transmitter is not disabled when TX Fault signal is active.
TX Disable is an input that is used to shut down the transmitter optical output.
On receiver side each module contains a PIN or APD photodetector for light to electrical current
conversion and a limiting amplifier.
The photo detector current is amplified by an electrical circuit which delivers two complementary data sig-
nals.
The module provides LOS alarm (LOS of input Power Signal alarm). This output signal indicates the
received optical power is below the worst case receiver sensitivity (as defined by the standard in use).
Depending on the SFP type, the optical access is compatible with
– single mode fibre (9/125 µm) or
– multi mode fibre (50/125 µm or 62.5/125 µm)
with standard LC optical connector.
The Transceiver has an EEPROM inside to provide Remote Inventory, containing information about
transceiver's capabilities, standard interfaces, manufacturer and others. The serial interface uses the 2-
wire serial CMOS EEPROM protocol defined for the ATMEL AT24C01A/02/04 family of components.
The digital diagnostic monitoring (DDM) is an SFP function supporting analog parameters measurements
as temperature, laser bias, laser power. It is an optional feature: the availability information is present in
the SFP Remote Inventory.
Technical Handbook SDH
Units Description
Alcatel 1850 TSS-320 Rel.1.1
8DG 07734 CAAA Edition 01 59/84