Description : What fiber property does numerical aperture (NA) measure?
Last Answer : NA measures the light-gathering ability of an optical fiber.
Description : Multimode step-index fibers have relatively large core diameters and large numerical apertures. These provide what benefit?
Last Answer : Make it easier to couple light from a light-emitting diode (LED) into the fiber.
Description : What four fiber properties determine the number of modes propagating in a multimode gradedindex fiber?
Last Answer : Numerical aperture (NA), relative refractive index difference ( D), profile parameter (α), and normalized frequency (V).
Description : Is the different angle of entry of light into an optical fiber when the diameter of the core is many times the wavelength of the light transmitted. a. Acceptance angle b. Modes c. Sensors d. Aperture
Last Answer : b. Modes
Description : Is the different angle of entry of light into an optical fiber when the diameter of the core is many times the wavelength of the light transmitted. ∙ a. Acceptance angle ∙ b. Modes ∙ c. Sensors ∙ d. Aperture
Description : Does underfilling a multimode optical fiber excite mainly high-order or low-order modes?
Last Answer : Low-order modes.
Description : The fiber's normalized frequency (V) determines how many modes a fiber can support. As the value of V increases, will the number of modes supported by the fiber increase or decrease?
Last Answer : Increase.
Description : A light ray incident on the optical fiber core is propagated along the fiber. Is the angle of incidence of the light ray entering the fiber larger or smaller than the acceptance angle
Last Answer : Smaller.
Description : In multimode step-index fibers, the majority of light propagates in the fiber core for what reason?
Last Answer : Most modes in multimode step-index fibers propagate far from cutoff.
Description : Numerical aperture is expressed as the a) NA = sin θa b) NA = cos θa c) NA = tan θa d) NA = sec θa
Last Answer : a) NA = sin θa
Description : What is a specific path the light takes in an optical fiber corresponding to a certain angle and number of reflection a. Mode b. Grade c. Numerical Aperture d. Dispersion
Last Answer : a. Mode
Description : What is a specific path the light takes in an optical fiber corresponding to a certain angle and number of reflection ∙ a. Mode ∙ b. Grade ∙ c. Numerical Aperture ∙ d. Dispersion
Description : A mode filter is a device that attenuates specific modes propagating in the core of an optical fiber. What mode propagating along single mode fibers do mode filters eliminate?
Last Answer : Second-order mode.
Description : As the core and cladding modes travel along the fiber, mode coupling occurs. What is mode coupling?
Last Answer : Mode coupling is the exchange of power between two modes.
Description : The numerical aperture of a coaxial cable with core and cladding indices given by 2.33 and 1.4 respectively is a) 3.73 b) 0.83 c) 3.46 d) 1.86
Last Answer : d) 1.86
Description : How many modes possible with a multimode step-index with a core diameter of 50 um, a core refractive index of 1.6, a cladding refractive index of 1.584, and a wavelength of 1300 nm. ∙ A. 456 ∙ B. 213 ∙ C. 145 ∙ D. 372
Last Answer : D. 372
Description : The numerical aperture of a fiber if the angle of acceptance is 15 degrees, is a. 017 b. 0.26 c. 0.50 d. 0.75
Last Answer : b. 0.26
Description : Chromatic dispersion can be eliminated by __________. ∙ A. using a monochromatic light source ∙ B. using a very small numerical aperture fiber ∙ C. using a graded-index fiber ∙ D. using a very sensitive photo detector
Last Answer : A. using a monochromatic light source
Description : It is a graphical representation of the magnitude of the refractive index across the fiber. ∙ A. mode ∙ B. index profile ∙ C. numerical aperture ∙ D. refractive index
Last Answer : B. index profile
Description : The effect of a large magnitude of the numerical aperture ∙ A. The amount of external light the fiber will accept is greater. ∙ B. The amount of external light the fiber will accept is less. ... The amount of modal dispersion will be less. ∙ D. The amount of chromatic dispersion will be greater.
Last Answer : The amount of external light the fiber will accept is greater.
Description : The numerical aperture of a fiber if the angle of acceptance is 15 degrees, is ∙ a. 017 ∙ b. 0.26 ∙ c. 0.50 ∙ d. 0.75
Last Answer : ∙ b. 0.26
Description : in multimode fibers, how do fiber joints increase fiber attenuation following the joint?
Last Answer : By disturbing the fiber's mode power distribution (MPD).
Description : A type of index of an optical fiber that has no cladding and whose central core has a non-uniform refractive index. ∙ A. graded index ∙ B. multimode ∙ C. single mode ∙ D. step-index
Last Answer : ∙ A. graded index
Description : A type of index profile of an optical fiber that has a central core and outside cladding with a uniform refractive index ∙ A. multimode ∙ B. graded index ∙ C. step-index ∙ D. single mode
Last Answer : ∙ C. step-index
Description : The graded-index multimode optical fiber has a core diameter of _____ nm. ∙ a. 0.5 ∙ b. 0.05 ∙ c. 0.0005 ∙ d. 5
Last Answer : ∙ a. 0.5
Description : A step-index multimode optical fiber has a core diameter of _____ nm. ∙ a. 0.02 ∙ b. 0.2 ∙ c. 2 ∙ d. 0.002
Last Answer : b. 0.2
Description : Do small core distortions formed by arc fusion's self alignment mechanism have more of an affect on light propagating through multimode or single mode fibers?
Last Answer : Single mode fibers.
Description : Multimode step-index fibers have a core and cladding of constant refractive index n1 and n2, respectively. Which refractive index, the core or cladding, is lower?
Last Answer : Cladding.
Description : List the standard core sizes for multimode step-index, multimode graded-index, and single mode fibers
Last Answer : Multimode step-index fibers: 50µm and 100µm. Multimode graded-index fibers: 50µm, 62.5µm, 85µm, and 100µm. Single mode fibers: between 8µm and 10µm.
Description : Explain the difference between multimode and single mode core-cladding concentricity errors.
Last Answer : Multimode core-cladding concentricity error is the distance between the core and cladding centers expressed as a percentage of core diameter while the single mode core-cladding concentricity error is just the distance between the core and cladding centers
Description : Why can multimode graded-index fiber 1300-nm systems using LEDs operate over longer distances and at higher bandwidths than 850-nm systems?
Last Answer : Longer distances and higher bandwidths are possible because fiber material losses and dispersion are significantly reduced at the 1300-nm region.
Description : What are the two methods used by fiber manufacturers to fabricate multimode and single mode glass fibers?
Last Answer : Vapor phase oxidation and direct-melt process.
Description : What are the most distinguishing characteristics of a multimode graded-index fiber?
Last Answer : Source-to-fiber coupling efficiency and insensitivity to microbending and macrobending losses.
Description : What multimode graded-index fiber offers the best overall performance for most applications?
Last Answer : 62.5/125 mm multimode graded-index fiber.
Description : Light travels faster in a material with a lower refractive index. Therefore, light rays that travel a longer distance in a lower refractive index travel at a greater average velocity. What effect does this have on multimode graded-index fiber modal dispersion and bandwidth?
Last Answer : Decreases the time difference between light rays, which reduces modal dispersion and increases fiber bandwidth.
Description : Multimode optical fibers can have a step-index or graded index refractive index profile. Which fiber, multimode step-index or multimode graded-index fiber, usually performs better?
Last Answer : Multimode graded-index fiber
Description : What two properties of the launch condition may affect multimode fiber attenuation measurements?
Last Answer : . Launch spot size and angular distribution.
Description : Modal dispersion affects the bandwidth of multimode systems. It is essential to adjust what three fiber properties to maximize system bandwidth?
Last Answer : Core diameter, NA, and index profile properties.
Description : Which type of optical fiber (multimode or single mode) tends to have lower loss and produces less signal distortion?
Last Answer : Single mode fiber.
Description : Modes of a light pulse that enter the fiber at one time exit the fiber at different times. This condition causes the light pulse to spread. What is this condition called?
Last Answer : Modal dispersion.
Description : Low-order and high-order modes propagate along an optical fiber. How are modes determined to be low-order or high order modes?
Last Answer : Depends on the bending caused by the velocity difference of the wave traveling through different mediums
Description : The refractive index is 2.33 and the critical angle is 350. Find the numerical aperture. a) 2 b) 1.9 c) 2.33 d) 12
Last Answer : b) 1.9
Description : The numerical aperture of a material with acceptance angle of 60 degree in water will be a) 1.15 b) 2.15 c) 5.21 d) 1.52
Last Answer : a) 1.15
Description : Find the acceptance angle of a material which has a numerical aperture of 0.707 in air. a) 30 b) 60 c) 45 d) 90
Last Answer : c) 45
Description : Magnification of compound microscope is not connected with (a) numerical aperture (b) focal length of objective (c) focal length of eye piece (d) tube length.
Last Answer : (a) numerical aperture
Description : Electron microscope has a high resolution power. This is due to (a) electromagnetic lenses (b) very low wavelength of electron beam (c) low wavelength of light source used (d) high numerical aperture of glass lenses used.
Last Answer : (b) very low wavelength of electron beam
Description : The numerical aperture is the ____________________ of the angle of
Last Answer : sine
Description : It is the figure of merit used to measure the magnitude of the acceptance angle. ∙ A. acceptance angle ∙ B. numerical aperture ∙ C. index profile
Last Answer : B. numerical aperture
Description : The effect of a large magnitude of the numerical aperture.
Last Answer : The amount of external light the fiber will accept is greater
Description : optical launch conditions exists if the launch spot size and angular distribution are larger than that of the fiber core?
Last Answer : Overfilled.