FOA CFOT LATEST 2026 EXAM QUESTIONS AND ANSWERS
GUARANTEE A+
✔✔Refractive index - ✔✔Property of optical materials that relates to velocity of light in
material.
✔✔Receiver - ✔✔A device containing a photodiode and signal conditioning circuitry
converting light to an electrical signal in fiber optic links.
✔✔Receive cable - ✔✔Known good fiber optic jumper cable attached to power meter
for loss testing. Must be made of matching fiber and connectors of cables tested.
✔✔Preform - ✔✔Large diameter glass rod where fiber is made or "drawn" from.
✔✔Polarization Mode Dispersion (PMD) - ✔✔Dispersion in singlemode fiber caused by
difference in speed of light of the fibers polarization modes.
✔✔Plastic-clad Silica (PCS) fiber - ✔✔Fiber made with glass core and plastic cladding.
✔✔Plastic Optical Fiber - ✔✔Fiber made of plastic core and cladding.
✔✔Pigtail - ✔✔Short length of fiber attached to a fiber component such as a laser or
coupler.
✔✔Photodiode - ✔✔Semiconductor that converts light to electrical signal, used in fiber
optic receivers.
✔✔Physical Contact (PC) - ✔✔Technique involving polishing the end surface of the
fiber to a convex surface to prevent reflectance.
✔✔Overfilled Launch - ✔✔Condition where incoming light in the fiber has a spot size
and numerical aperture larger than accepted by fiber, filling all modes in the fiber.
✔✔Optical Time Domain Reflectometer (OTDR) - ✔✔An instrument that uses
backscattered light to find faults in optical fiber and measure loss.
✔✔Optical Power - ✔✔Amount of radiant energy per unit time, expressed in Watts, in
dBm (0dB = 1mW) or dB* (0dB* = 1 microWatt)
✔✔Optical Loss Test Set (OLTS) - ✔✔Measurement instrument for optical loss which
includes both meter and source.
✔✔Optical Amplifier - ✔✔Device that amplifies light without converting it to an electrical
signal.
, ✔✔Numerical Aperture (NA) - ✔✔Measure of the light acceptance angle of the fiber.
✔✔Network - ✔✔A system of cables, hardware and equipment used for
communications.
✔✔Nanometer (nm) - ✔✔Used to measure the wavelength of light.
✔✔Multimode Fiber - ✔✔Fiber with core diameter much larger than wavelength of light
transmitted, allowing many modes of light to propagate. Commonly uses LED sources
for lower speed, short distance links.
✔✔Mode - ✔✔Single electromagnetic field pattern that travels in fiber.
✔✔Mode stripper - ✔✔Device that removes light in cladding of an optical fiber
✔✔Mode scrambler - ✔✔Device that mixes optical power in fiber to achieve equal
power distribution in all modes.
✔✔Mode filter - ✔✔Device that removes optical power in higher order modes in fiber.
✔✔Mode field diamter - ✔✔Measure of the core size in singlemode fiber.
✔✔Modal dispersion - ✔✔Temporal spreading of pulse in optical waveguide caused by
modal effects.
✔✔Micron (*m) - ✔✔Used to measure wavelength of light and diameter of fiber
✔✔Mechanical Splice - ✔✔Semi-permanent connection between two fibers made with
adhesive and an alignment device.
✔✔Margin - ✔✔The additional amount of loss that can be tolerated in a link.
✔✔Loss Budget - ✔✔Amount of power lost in the link.Often used as the maximum
amount of loss that can be tolerated by a given link.
✔✔Optical Loss - ✔✔Amount of optical power lost as light is transmitted through fiber,
splices, couplers, etc.
✔✔Long Wavelength - ✔✔Light in the 1300 and 1550 nm ranges can be described as
this.
✔✔Fiber Optic Link - ✔✔Combination of transmitter, receiver and fiber optic cable
capable of transmitting data. May be analog or digital.
GUARANTEE A+
✔✔Refractive index - ✔✔Property of optical materials that relates to velocity of light in
material.
✔✔Receiver - ✔✔A device containing a photodiode and signal conditioning circuitry
converting light to an electrical signal in fiber optic links.
✔✔Receive cable - ✔✔Known good fiber optic jumper cable attached to power meter
for loss testing. Must be made of matching fiber and connectors of cables tested.
✔✔Preform - ✔✔Large diameter glass rod where fiber is made or "drawn" from.
✔✔Polarization Mode Dispersion (PMD) - ✔✔Dispersion in singlemode fiber caused by
difference in speed of light of the fibers polarization modes.
✔✔Plastic-clad Silica (PCS) fiber - ✔✔Fiber made with glass core and plastic cladding.
✔✔Plastic Optical Fiber - ✔✔Fiber made of plastic core and cladding.
✔✔Pigtail - ✔✔Short length of fiber attached to a fiber component such as a laser or
coupler.
✔✔Photodiode - ✔✔Semiconductor that converts light to electrical signal, used in fiber
optic receivers.
✔✔Physical Contact (PC) - ✔✔Technique involving polishing the end surface of the
fiber to a convex surface to prevent reflectance.
✔✔Overfilled Launch - ✔✔Condition where incoming light in the fiber has a spot size
and numerical aperture larger than accepted by fiber, filling all modes in the fiber.
✔✔Optical Time Domain Reflectometer (OTDR) - ✔✔An instrument that uses
backscattered light to find faults in optical fiber and measure loss.
✔✔Optical Power - ✔✔Amount of radiant energy per unit time, expressed in Watts, in
dBm (0dB = 1mW) or dB* (0dB* = 1 microWatt)
✔✔Optical Loss Test Set (OLTS) - ✔✔Measurement instrument for optical loss which
includes both meter and source.
✔✔Optical Amplifier - ✔✔Device that amplifies light without converting it to an electrical
signal.
, ✔✔Numerical Aperture (NA) - ✔✔Measure of the light acceptance angle of the fiber.
✔✔Network - ✔✔A system of cables, hardware and equipment used for
communications.
✔✔Nanometer (nm) - ✔✔Used to measure the wavelength of light.
✔✔Multimode Fiber - ✔✔Fiber with core diameter much larger than wavelength of light
transmitted, allowing many modes of light to propagate. Commonly uses LED sources
for lower speed, short distance links.
✔✔Mode - ✔✔Single electromagnetic field pattern that travels in fiber.
✔✔Mode stripper - ✔✔Device that removes light in cladding of an optical fiber
✔✔Mode scrambler - ✔✔Device that mixes optical power in fiber to achieve equal
power distribution in all modes.
✔✔Mode filter - ✔✔Device that removes optical power in higher order modes in fiber.
✔✔Mode field diamter - ✔✔Measure of the core size in singlemode fiber.
✔✔Modal dispersion - ✔✔Temporal spreading of pulse in optical waveguide caused by
modal effects.
✔✔Micron (*m) - ✔✔Used to measure wavelength of light and diameter of fiber
✔✔Mechanical Splice - ✔✔Semi-permanent connection between two fibers made with
adhesive and an alignment device.
✔✔Margin - ✔✔The additional amount of loss that can be tolerated in a link.
✔✔Loss Budget - ✔✔Amount of power lost in the link.Often used as the maximum
amount of loss that can be tolerated by a given link.
✔✔Optical Loss - ✔✔Amount of optical power lost as light is transmitted through fiber,
splices, couplers, etc.
✔✔Long Wavelength - ✔✔Light in the 1300 and 1550 nm ranges can be described as
this.
✔✔Fiber Optic Link - ✔✔Combination of transmitter, receiver and fiber optic cable
capable of transmitting data. May be analog or digital.
