The Cisco ONS 15501 is a low-noise, gain-flattened C-band optical EDFA (erbium-doped fiber
amplifier). This guide describes how to install and operate the Cisco ONS 15501.
The Cisco ONS 15501 complements high-performance digital transmitters in topologies requiring
amplification of 1550-nm optical signals.
This chapter includes the following sections:
The Cisco ONS 15501 contains an erbium-doped optical fiber, optical couplers, and one or more pump
lasers and isolators. An optical signal (within a range of 1530 to 1563 nm) arrives at the input connector.
The 1550- nm signal travels through a length of erbium-doped fiber cable. Inside the amplifier, light
from a laser at a wavelength of 980 nm (called the pump laser) is used to amplify the signal at 1550 nm.
The amplified signal is coupled to the output cable for transmission to a node. In longer cable runs, up
to six Cisco ONS 15501 EDFAs can be connected in tandem.
The Cisco ONS 15501 uses 980-nm pump lasers that are built to meet Bellcore TR-NWT-000468 and
MIL-883D standards. With a noise figure approaching the theoretical minimum, the amplifier achieves
results superior to that obtained from a 1480-nm pump laser. The 980-nm pump laser has a long lifetime,
exceeding one million hours. Use of a small number of high-quality components makes the
Cisco ONS 15501 a highly reliable product.
The Cisco ONS 15501 is polarization, modulation, and frequency independent, and operates in
gain-controlled mode. It is optimized for different input and output powers, and can be used as a
preamplifier, inline amplifier, or booster. The unit provides excellent gain flatness for the cascading of
amplifiers in DWDM applications.
The Cisco ONS 15501 is physically designed to fit into a 19-inch, 23-inch, or ETSI equipment rack, with
front, middle, or rear mounting capability. It is equipped with connectors for optional monitoring either
locally or remotely.
78-14134-01, Release 1.0
Product Description, page 1-1
Optical Specifications, page 1-2
Key Features, page 1-2
Cisco ONS 15501 Applications, page 1-5
Cisco ONS 15501 Front Panel, page 1-7
C H A P T E R
Cisco ONS 15501 User Guide