Chapter 14
Basic Measurement and Monitoring
Techniques
Abstract This chapter discusses measurement techniques that have been developed
for characterizing the operational behavior of devices and fibers, for ensuring that the
correct components have been selected for a particular application, and for verifying
that the network is configured properly. In addition, various operational methods
for performance monitoring are needed to verify that all the design and operating
specifications of a link are met when it is running. A wide selection of sophisticated
test equipment exists for these measurement requirements and procedures.
Engineers from many diverse disciplines need to make performance measurements
at all stages of the design, installation, and operation of an optical fiber communication network. Numerous levels of measurement techniques have been developed for
characterizing the operational behavior of devices and fibers, for ensuring that the
correct components have been selected for a particular application, and for verifying
that the network is configured properly. In addition, various methods for monitoring
operational performance are needed to verify that all the design and operating specifications of a link are met when it is running. A wide selection of sophisticated test
equipment exists for each of these measurement categories.
During the link design phase an engineer can find the operational parameters of
many passive and active components on vendor data sheets. These include fixed
parameters for fibers, passive optical devices, and optoelectronic components such
as light sources, photodetectors, and optical amplifiers. For example, fixed fiber
parameters include core and cladding diameters, refractive-index profile, mode-field
diameter, and cut-off wavelength. Once such fixed parameters are known, generally
there is no need for a link design engineer to measure them again.
However, variable parameters of communication system elements, such as optoelectronic components, may change with operational conditions and need to be
measured before, during, and after a link is fielded. Of particular importance are
accurate and comprehensive measurements of the optical fiber, because this component cannot be replaced readily once it has been installed. Although many physical
properties of fiber remain constant, the attenuation and dispersions of a fiber can
change during fiber cabling and cable installation. In single-mode fibers, chromatic
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
G. Keiser, Fiber Optic Communications,
https://doi.org/10.1007/978-981-33-4665-9_14
577
Basic Measurement and Monitoring
Techniques
Abstract This chapter discusses measurement techniques that have been developed
for characterizing the operational behavior of devices and fibers, for ensuring that the
correct components have been selected for a particular application, and for verifying
that the network is configured properly. In addition, various operational methods
for performance monitoring are needed to verify that all the design and operating
specifications of a link are met when it is running. A wide selection of sophisticated
test equipment exists for these measurement requirements and procedures.
Engineers from many diverse disciplines need to make performance measurements
at all stages of the design, installation, and operation of an optical fiber communication network. Numerous levels of measurement techniques have been developed for
characterizing the operational behavior of devices and fibers, for ensuring that the
correct components have been selected for a particular application, and for verifying
that the network is configured properly. In addition, various methods for monitoring
operational performance are needed to verify that all the design and operating specifications of a link are met when it is running. A wide selection of sophisticated test
equipment exists for each of these measurement categories.
During the link design phase an engineer can find the operational parameters of
many passive and active components on vendor data sheets. These include fixed
parameters for fibers, passive optical devices, and optoelectronic components such
as light sources, photodetectors, and optical amplifiers. For example, fixed fiber
parameters include core and cladding diameters, refractive-index profile, mode-field
diameter, and cut-off wavelength. Once such fixed parameters are known, generally
there is no need for a link design engineer to measure them again.
However, variable parameters of communication system elements, such as optoelectronic components, may change with operational conditions and need to be
measured before, during, and after a link is fielded. Of particular importance are
accurate and comprehensive measurements of the optical fiber, because this component cannot be replaced readily once it has been installed. Although many physical
properties of fiber remain constant, the attenuation and dispersions of a fiber can
change during fiber cabling and cable installation. In single-mode fibers, chromatic
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
G. Keiser, Fiber Optic Communications,
https://doi.org/10.1007/978-981-33-4665-9_14
577