Fiber Install and Activation Exam Review Guide: Answered 2025
What is the Fiber-optic cable term for optical transport that is restricted to one path (mode) for
light propagation through the core of an optical fiber? - (answers)Single Mode Fiber
A type of optical fiber with large core diameters which allow multiple modes, or paths, upon
which the optical signal travels is known as what? - (answers)Multi - Mode Fiber
In fiber-optic terminology, what is "window" ? - (answers)Refers to a center optical wavelength,
as well as a range of wavelengths on either side of the center wavelength
What are the four standard optical windows? - (answers)850 nm, 1,300 nm, 1,550 nm, and 1,625
nm.
What window is exclusively used for multimode fiber? - (answers)850 nm
What is an Erbium-doped fiber amplifier (EDFA)? - (answers)An optical amplifier that uses
active erbium-doped fiber and a pump source (laser) to boost or amplify the optical signal?
What are the three basic components of all fiber-optic communications networks? - (answers)(1)
an optical transmitter with a light source; (2) the optical fiber (3) an optical receiver with a
photodetector.
What characteristic of a fiber-optic cable enhances the security of signals being transported in the
network? - (answers)Fiber optics are typically made of glass which is a dielectric material which
is basically immune to EMI and RFI
What telecommunication standard designation encompasses all things voice, video, and data? -
(answers)ITU Telecommunications Standardization Sector ITU-T
Single -mode fiber-optic cable is optimized to transport which wavelengths? - (answers)1310 nm
& 1550 nm
,An optical fiber consists of what three basic parts? - (answers)Core, Cladding, and Coating
What does the spectral width of a laser or Light Emitting Diode (LED) define? - (answers)A
measurement for the band of wavelengths over which a laser light source emits its energy,
generally measured in nanometers (Nm) between the half power points of an optical light sources
maximum amplitude at the center frequency Full Width Half Maximum (FWHM)
Which type of laser is ideal for analog, high speed digital, and optical multiplexing networks
because of its high SNR (signal to noise ratio) and small spectral widths? - (answers)Distributed
Feed Back (DFB) laser
What are the two common types of laser diodes used in fiber optic networks? -
(answers)Distributed Feed Back (DFB) lasers and Fabry-Perot (F-P) lasers
What are two types of optical detector used in fiber-optic networks? - (answers)Positive-
Intrinsic-Negative diode (PIN) & Avalanche Photo Diode (APD)
What are the two methods used to modulate an optical carrier ? - (answers)Direct Modulation
and Indirect Modulation
How is optimal sensitivity in an optical receiver obtained? - (answers)Efficient Coupling to the
optical fiber to transfer the maximum amount of optical power from the optical fiber to the
receiver.
Why is the positive -intrinsic - negative (PIN) photo-diode the most common type of photo-diode
used in optical receivers? - (answers)It is relatively inexpensive and can be operated from a
standard power supply.
What is the primary difference between an avalanche photo-diode (APD) and a positive-
intrinsic-negative (PIN) photo-diode? - (answers)APD require a higher voltage power supply and
more complex circuitry
, What type of electrical detection can improve the sensitivity of an optical reliever by as much as
20dB? - (answers)Coherent Detection
Which standards organization is considered to be the creator of the world's most recognized
communications standards, known as "recommendations?" - (answers)The International
Telecommunication Union (ITU).
In which component in a fiber-optics communication system do changes to the intensity of the
optical signal occur? - (answers)The optical transmitter.
What is a drawback of using Fabry-Perot (F-P) lasers in high-speed data (HSD) networks? -
(answers)The emission of a number of discrete wavelengths or side modes.
Why are laser diodes most effective when coupled to single mode fiber? - (answers)Its high
coupled power, directionality, and speed.
What are the factors that contribute to an optical receiver's sensitivity? - (answers)Noise,
responsivity, response time, linear response, back reflection, and optical detector material.
What is a positive-intrinsic-negative (PIN) diode? - (answers)An optical detector with current
flow that is linear to the intensity of light photons, with one electron/hole pair created for every
absorbed photon until saturation.
What does the amplification process in an avalanche photodiode (APD) introduce into the
electrical output of an optical detector? - (answers)Noise
What functions does the detector in an optical receiver perform? - (answers)Conversion of an
optical carrier to an electrical signal, and demodulation of the modulated optical carrier.
What happens if the optical signal exceeds the maximum specified input power into a
photodetector? - (answers)Nonlinear operation resulting in distortion, data errors, and signal loss.
What is the Fiber-optic cable term for optical transport that is restricted to one path (mode) for
light propagation through the core of an optical fiber? - (answers)Single Mode Fiber
A type of optical fiber with large core diameters which allow multiple modes, or paths, upon
which the optical signal travels is known as what? - (answers)Multi - Mode Fiber
In fiber-optic terminology, what is "window" ? - (answers)Refers to a center optical wavelength,
as well as a range of wavelengths on either side of the center wavelength
What are the four standard optical windows? - (answers)850 nm, 1,300 nm, 1,550 nm, and 1,625
nm.
What window is exclusively used for multimode fiber? - (answers)850 nm
What is an Erbium-doped fiber amplifier (EDFA)? - (answers)An optical amplifier that uses
active erbium-doped fiber and a pump source (laser) to boost or amplify the optical signal?
What are the three basic components of all fiber-optic communications networks? - (answers)(1)
an optical transmitter with a light source; (2) the optical fiber (3) an optical receiver with a
photodetector.
What characteristic of a fiber-optic cable enhances the security of signals being transported in the
network? - (answers)Fiber optics are typically made of glass which is a dielectric material which
is basically immune to EMI and RFI
What telecommunication standard designation encompasses all things voice, video, and data? -
(answers)ITU Telecommunications Standardization Sector ITU-T
Single -mode fiber-optic cable is optimized to transport which wavelengths? - (answers)1310 nm
& 1550 nm
,An optical fiber consists of what three basic parts? - (answers)Core, Cladding, and Coating
What does the spectral width of a laser or Light Emitting Diode (LED) define? - (answers)A
measurement for the band of wavelengths over which a laser light source emits its energy,
generally measured in nanometers (Nm) between the half power points of an optical light sources
maximum amplitude at the center frequency Full Width Half Maximum (FWHM)
Which type of laser is ideal for analog, high speed digital, and optical multiplexing networks
because of its high SNR (signal to noise ratio) and small spectral widths? - (answers)Distributed
Feed Back (DFB) laser
What are the two common types of laser diodes used in fiber optic networks? -
(answers)Distributed Feed Back (DFB) lasers and Fabry-Perot (F-P) lasers
What are two types of optical detector used in fiber-optic networks? - (answers)Positive-
Intrinsic-Negative diode (PIN) & Avalanche Photo Diode (APD)
What are the two methods used to modulate an optical carrier ? - (answers)Direct Modulation
and Indirect Modulation
How is optimal sensitivity in an optical receiver obtained? - (answers)Efficient Coupling to the
optical fiber to transfer the maximum amount of optical power from the optical fiber to the
receiver.
Why is the positive -intrinsic - negative (PIN) photo-diode the most common type of photo-diode
used in optical receivers? - (answers)It is relatively inexpensive and can be operated from a
standard power supply.
What is the primary difference between an avalanche photo-diode (APD) and a positive-
intrinsic-negative (PIN) photo-diode? - (answers)APD require a higher voltage power supply and
more complex circuitry
, What type of electrical detection can improve the sensitivity of an optical reliever by as much as
20dB? - (answers)Coherent Detection
Which standards organization is considered to be the creator of the world's most recognized
communications standards, known as "recommendations?" - (answers)The International
Telecommunication Union (ITU).
In which component in a fiber-optics communication system do changes to the intensity of the
optical signal occur? - (answers)The optical transmitter.
What is a drawback of using Fabry-Perot (F-P) lasers in high-speed data (HSD) networks? -
(answers)The emission of a number of discrete wavelengths or side modes.
Why are laser diodes most effective when coupled to single mode fiber? - (answers)Its high
coupled power, directionality, and speed.
What are the factors that contribute to an optical receiver's sensitivity? - (answers)Noise,
responsivity, response time, linear response, back reflection, and optical detector material.
What is a positive-intrinsic-negative (PIN) diode? - (answers)An optical detector with current
flow that is linear to the intensity of light photons, with one electron/hole pair created for every
absorbed photon until saturation.
What does the amplification process in an avalanche photodiode (APD) introduce into the
electrical output of an optical detector? - (answers)Noise
What functions does the detector in an optical receiver perform? - (answers)Conversion of an
optical carrier to an electrical signal, and demodulation of the modulated optical carrier.
What happens if the optical signal exceeds the maximum specified input power into a
photodetector? - (answers)Nonlinear operation resulting in distortion, data errors, and signal loss.
