Description : List the types of materials used in fabricating low-loss, long wavelength optical fibers.
Last Answer : Heavy-metal fluorides, chalcogenide glasses, and crystalline materials.
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 : Will the cutoff wavelength of uncabled fibers (lcf) generally have a value higher or lower than the cutoff wavelength of cabled fibers (λcc)?
Last Answer : Higher.
Description : The cutoff wavelength of matched-clad and depressed-clad single mode fibers varies according to the fiber's radius of curvature and length. The cutoff wavelength of which single mode fiber type is more sensitive to length
Last Answer : Depressed-clad.
Description : Which dispersion mechanism (material or waveguide) is a function of the size of the fiber's core relative to the wavelength of operation?
Last Answer : Waveguide dispersion.
Description : Silica (pure glass) fibers are used because of their low intrinsic material absorption at the wavelengths of operation. This wavelength of operation is between two intrinsic absorption regions. What are these two regions called? What are the wavelengths of operation for these two regions?
Last Answer : Ultraviolet absorption region (below 400 nm) and infrared absorption region (above 2000 nm).
Description : Which type of optical splitter (Y-coupler or T-coupler) splits only a small amount of power from the input fiber to one of the output fibers?
Last Answer : T-coupler
Description : Which type of fiber optic connector (butt-jointed or expanded beam) brings the prepared ends of two optical fibers into close contact?
Last Answer : Butt-jointed connectors.
Description : What is the basic fiber cleaving technique for preparing optical fibers for coupling?
Last Answer : Score-and-break.
Description : Which semiconductor sources (LD or LED) emit more focused light and are capable of launching sufficient optical power into both single mode and multimode fibers?
Last Answer : LDs.
Description : List the three techniques used by manufacturers to buffer optical fibers.
Last Answer : Tight-buffered, loose-tube, and gel-filled loose-tube.
Description : List three benefits that properly cabled optical fibers provide.
Last Answer : a. Protect optical fibers from damage or breakage during installation and over the fiber's lifetime. b. Provide stable fiber transmission characteristics compared with uncabled fibers. c. Maintain the physical integrity of the optical fiber.
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 : 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 : Optical fibers or cables should never be bent at a radius of curvature smaller than a certain value. Identify this radius of curvature
Last Answer : Minimum bend radius.
Description : What are the two basic types of optical fibers?
Last Answer : Multimode and single mode fibers.
Description : How can loss be reduced during construction (or fabrication) of optical fibers?
Last Answer : By removing the impurities from optical fiber.
Description : If the length of the fiber point defect changes with pulse duration, is the OTDR signal deviation a point defect or a region of high fiber attenuation?
Last Answer : A point defect.
Description : In conductors, which two parameters are same? a) Wavelength and phase constant b) Phase and attenuation constant c) Attenuation constant and skin depth d) Skin depth and wavelength
Last Answer : b) Phase and attenuation constant
Description : Which is not a possible cause of optical fiber loss? ∙ a. Impurities ∙ b. Glass attenuation ∙ c. Stepped index operation ∙ d. Microbending
Last Answer : ∙ c. Stepped index operation
Description : Optical fibers are the fine strands of _____. A. Glass B. Iron C. Calcium D. Mercury
Last Answer : ANSWER: A
Description : Optical Fiber Optical fibers are the fine strands of _____. A. Glass B. Iron C. Calcium D. Mercury
Description : _______uses two optical fibers anda long-wavelaser source. A) 1000Base-SX B) 1000Base-LX C) 1000Base-T D) none of the above
Last Answer : 1000Base-LX
Description : ______ uses two optical fibers and a short-wave laser source, A) 1000Base-SX B) 1000Base-LX C) 1000Base-T D) none of the above
Description : Optical fibers for telecommunications are typically about _____ mils thick and consists of a glass core, a glass cladding of lower index of refraction, and a protective coating ∙ a. 5 ∙ b. 6 ∙ c. 7 ∙ d. 8
Last Answer : ∙ a. 5
Description : The ultrapure glass used to manufacture optical fibers is approximately ___pure ∙ a. 99.9 % ∙ b. 99.99 % ∙ c. 99.999 % ∙ d. 99.9999 %
Last Answer : d. 99.9999 %
Description : Unlike coax and twisted pair, optical fibers are immune to a. High-frequency transmission b. Signal attenuation c. Power loss d. Electromagnetic interference
Last Answer : Unlike coax and twisted pair, optical fibers are immune to Electromagnetic interference
Description : Light travels along optical fibers by
Last Answer : Light travels along optical fibers by Total internal reflection
Description : What three factors must be considered in the transmission of a surface wave to reduce attenuation?
Last Answer : (a) electrical properties of the terrain (b) frequency (c) polarization of the antenna
Description : Is the attenuation of a coaxial cable independent of frequency?
Last Answer : No.
Description : Why is a dead-zone fiber placed between the test fiber and OTDR when conducting attenuation measurements?
Last Answer : To reduce the effect of the initial reflection at the OTDR
Description : What two properties of the launch condition may affect multimode fiber attenuation measurements?
Last Answer : . Launch spot size and angular distribution.
Description : Define attenuation.
Last Answer : Attenuation is the loss of optical power as light travels along the fiber.
Description : Attenuation is mainly a result of what three properties?
Last Answer : Light absorption, scattering, and bending losses.
Description : Which are more sensitive to alignment errors, single mode or multimode fibers?
Last Answer : Single mode.
Description : When the axes of two connected fibers are no longer in parallel, the two connected fibers are in what kind of misalignment?
Last Answer : Angular misalignment.
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 : 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 five characteristics do applications using plastic clad silica (PCS) and all-plastic fibers typically have?
Last Answer : High NA, low bandwidth, tight bend radius, short length, and low cost.
Description : Give two reasons why the value of the normalized frequency (V) is varied in single mode stepindex fibers?
Last Answer : To increase performance and reduce losses caused by bending and splicing.
Description : In single mode operation, the value of the normalized frequency (V) should remain near the 2.405 level. If the value of V is less than 1, do single mode fibers carry a majority of the power in the core or cladding material?
Last Answer : Cladding material.
Description : What are the two basic types of single mode step-index fibers?
Last Answer : Matched-clad and depressed-clad.
Description : Light propagates in multimode graded-index fibers according to refraction and total internal reflection. When does total internal reflection occur?
Last Answer : When the angle of incidence becomes larger than the critical angle of incidence.
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 : 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 : 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 : The value of the normalized frequency parameter (V) relates the core size with mode propagation. When single mode fibers propagate only the fundamental mode, what is the value of V?
Last Answer : V≤2.405.
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.