Encapsulation type
Appearance type of an optical module. Encapsulation types of optical modules include
SFP, eSFP, SFP+, XFP, and QSFP+.
l
SFP: small form-factor pluggable.
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eSFP: enhanced small form-factor pluggable. An eSFP module is an SFP module
that supports monitoring of voltage, temperature, bias current, transmit optical
power, and receive optical power. Because all the SFP optical modules support
these monitoring functions, eSFP is also called SFP.
l
SFP+: small form-factor pluggable plus, SFP with a higher rate. SFP+ modules are
more sensitive to electromagnetic interference (EMI) because they have a higher
rate. To reduce EMI, SFP+ modules have more springs than SFP modules.
l
XFP: 10GE optical module. X is the Roman numeral 10.
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QSFP+: Quad SFP+, four-channel SFP+.
Center wavelength
Wavelength measured at the midpoint of the half-amplitude line in the transmit spectrum.
Fiber mode
Mode of fibers defining based on core diameters and features of optical fibers. Optical
fibers are classified into single-mode fibers and multi-mode fibers. Generally, multi-
mode fibers have large core diameters and severe dispersion, so they transmit optical
signals over short distances when working with multi-mode optical modules. Single-
mode fibers have small dispersion and can transmit optical signals over long distances
when working with single-mode optical modules.
Modal bandwidth
Bandwidth measured at a point with transmit power several dB lower than that of the
point with the peak center wavelength. Modal bandwidth reflects spectrum
characteristics of an optical module.
Fiber diameter
Diameter of the core of a fiber. According to international standards for optical fibers,
the diameter of a multi-mode fiber is 62.5 um or 50 um, and the diameter of a single-
mode fiber is 9 um.
Fiber class
Optical signals with different wavelengths have their best working windows in different
optical fibers. To help efficiently adjust wavelengths or dispersion features of optical
fibers and change their refractive indexes, the following classes are defined: multi-mode
fiber (G.651), common single-mode fiber (G.652), shifted dispersion fiber (G.653), and
non-zero shifted dispersion fiber (G.655). Multi-mode fiber (G.651) and common single-
mode fiber (G.652) are commonly used fiber classes.
Connector type
Type of the interface on an optical module to accommodate a fiber. Commonly used
connector types are LC (applicable to all the SFP, SFP+, and XFP modules) and MPO
(applicable to some of QSFP+ modules).
Transmit optical power
Output optical power of an optical module when it is working properly.
Maximum receiver
sensitivity
Minimum average input optical power that the receiver of an optical module can receive
within a range of bit error rate (BER = 10
-12
).
CloudEngine 7800&6800&5800 Series Switches
Hardware Description
6 Optical Module
Issue 16 (2015-08-26)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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