Description : Type of bend that occurs as a result of differences in thermal contraction rates between the core and the cladding material. ∙ A. Macrobending ∙ B. Microbending ∙ C. Quad bending ∙ D. Constant-radius bending
Last Answer : B. Microbending
Description : These bends are caused by excessive pressure and tension and generally occur while fiber are bent during handling or installation. ∙ A. microbending ∙ B. macrobending ∙ C. constant-radius bending ∙ D. kinks
Last Answer : C. constant-radius bending
Description : Fiber-to-fiber coupling loss is affected by intrinsic and extrinsic coupling losses. Can intrinsic coupling losses be limited by limiting fiber mismatches?
Last Answer : Yes.
Description : In fiber-to-fiber connections, Fresnel reflection is one source of coupling losses. Light is reflected back into the source fiber and is lost. What causes Fresnel reflection?
Last Answer : A step change in refractive index that occurs at fiber joints, caused by fiber separation.
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 : Will fiber coupling loss generally increase or decrease if the mode field diameter of a single mode fiber is decreased?
Last Answer : Increase.
Description : The dominant loss mechanisms in silica fiber are ∙ a. Absorption and radiation losses ∙ b. Absorption and Rayleigh scattering ∙ c. Coupling and radiation losses ∙ d. Radiation and modal dispersion
Last Answer : b. Absorption and Rayleigh scattering
Description : It is caused by the difference in the propagation time of light rays that take different paths down the fiber. ∙ A. modal dispersion ∙ B. microbending ∙ C. Rayleigh scattering ∙ D. chromatic dispersion
Last Answer : A. modal dispersion
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 : Is coupling loss from fiber separation and lateral misalignment more critical in expanded-beam or butt-jointed connectors?
Last Answer : Butt-jointed connectors.
Description : Does coupling loss from refractive index profile difference result when the receiving fiber has a larger profile parameter
Last Answer : Fiber alignment.
Description : What is the basic fiber cleaving technique for preparing optical fibers for coupling?
Last Answer : Score-and-break.
Description : How does index matching gel affect the amount of coupling loss caused by (a) fiber separation, (b) lateral misalignment, and (c) angular misalignment?
Last Answer : (a) Reduces coupling loss, (b) does not change coupling loss, and (c) increases coupling loss
Description : What connection properties result in fiber optic connector coupling loss?
Last Answer : Poor fiber alignment and end preparation, fiber mismatches, and Fresnel reflection.
Description : How is fiber sensitivity to bending losses reduced?
Last Answer : Fiber sensitivity to bending losses can be reduced if the refractive index of the core is increased and/or if the overall diameter of the fiber increases.
Description : Scattering losses are caused by the interaction of light with density fluctuations within a fiber. What are the two scattering mechanisms called when the size of the density fluctuations is (a) greater than and (b) less than one-tenth of the operating wavelength?
Last Answer : . (a) Mie scattering; (b) Rayleigh scattering.
Description : Give two reasons why optical fiber manufacturers depart from the traditional circular core and cladding, low-loss glass fiber design?
Last Answer : To increase performance and reduce cost
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 : The refractive index of a fiber core is uniform and undergoes an abrupt change at the corecladding boundary. Is this fiber a step-index or graded-index fiber?
Last Answer : 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 launch conditions exists if the launch spot size and angular distribution are larger than that of the fiber core?
Last Answer : Overfilled.
Description : The number of modes propagated in a multimode fiber depends on core size and numerical aperture (NA). If the core size and the NA decrease, will the number of modes propagated increase or decrease?
Last Answer : Decrease.
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 : When connector losses, splice losses and coupler losses are added, what is the limiting factor? ∙ A. source power ∙ B. fiber attenuation ∙ C. connector and splice loss ∙ D. detector sensitivity
Last Answer : D. detector sensitivity
Description : When connectorlosses,splice losses, and couplerlosses are added,whatisthe finallimitingfactor? a. Source power b. Fiber attenuation c. Connector and splice losses d. Detector sensitivity
Last Answer : d. Detector sensitivity
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 : The different angles of entry of light into an optical fiber when the diameter of the core is many times the wavelength of the light transmitter is known as ________. A. refraction B. sensor C. mode D. emitter
Last Answer : C. mode
Description : EMD is best described by which statement? ∙ A. 70 percent of the core diameter and 70% of the fiber NA should be filled with light. ∙ B. 70 percent of the fiber diameter and 70% of the ... be measured at the output. ∙ D. 70 percent of the unwanted wavelengths should be attenuated by the fiber.
Last Answer : 70 percent of the core diameter and 70% of the fiber NA should be filled with light.
Description : The refractive index number is ∙ A. a number which compares the transparency of a material with that of air ∙ B. a number of assigned by the manufacturer to the fiber in question ∙ C. a number which determines the core diameter ∙ D. a term describing core elasticity
Last Answer : A. a number which compares the transparency of a material with that of air
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 : A single mode optical fiber has a core diameter of _____ nm. ∙ a. 0.1 ∙ b. 0.01 ∙ c. 0.2 ∙ d. 0.05
Last Answer : a. 0.1
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 : The reflective index numberis a. anumberwhichcomparesthe transparencyof amaterialwiththatof air b. a number assigned by the manufacturer to the fiber in question c. a number which determines the core diameter d. a term for describing core elasticity
Last Answer : a. anumberwhichcomparesthe transparencyof amaterialwiththatof air
Description : How is the core diameter defined?
Last Answer : The core diameter is defined as the diameter at which the near field intensity is 2.5 percent of the maximum intensity.
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 : Delay differences between the source wavelengths occur as the optical signal propagates along the fiber. What is this called?
Last Answer : Differential group delay t(l).
Description : The horizontal line which cuts across 'L1' shown in figure 'A' of the illustration indicates a/an ______________. EL-0091 A. iron core B. saturable core C. air gap D. capacitive coupling
Last Answer : Answer: B
Description : The coefficient of coupling between two air core coils depends on (A) mutual inductance between two coils only (B) self inductances of the two coils only (C) mutual inductance and self inductances of the two coils (D) none
Last Answer : The coefficient of coupling between two air core coils depends on mutual inductance and self inductances of the two coils
Description : The stability of transmitted signal from a simple Hartley oscillator single transmitter which is coupled to and antenna wire affected by ______. A. Chirping of oscillator B. Closer coupling between the oscillator and the antenna. C. Location of antenna D. Material of antenna
Last Answer : B. Closer coupling between the oscillator and the antenna.
Description : Loose or inefficient coupling of energy into or out of a waveguide can be accomplished by the use of what method?
Last Answer : Slots and apertures.
Description : What are two advantages of this type of coupling?
Last Answer : It uses fewer components than capacitive coupling and can provide an increase in gain.
Description : What is the most common form of coupling for an rf amplifier?
Last Answer : Transformer coupling.
Description : If current gain is required from an rf amplifier, what type of component should be used as an output coupling element?
Last Answer : A step-down transformer.
Description : What effect does flux leakage in a transformer have on the coefficient of coupling (K) in the transformer?
Last Answer : it causes K to be less than unity (I).
Description : Is coupling loss from angular misalignment more critical in expanded beam or butt-jointed connectors?
Last Answer : Expanded beam connectors.
Description : What are the two methods used for feedback coupling?
Last Answer : Inductive and capacitive.
Description : What are the main causes of coupling loss?
Last Answer : Poor fiber end preparation and poor fiber alignment.
Description : In a circuit using grid-leak biasing, the coupling capacitor (Cc) chargcharge path?
Last Answer : rkg, the cathode to grid resistance.