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 : For all transparent material substances, the index of refraction A. A.is less than 1 B. B.is greater than 1 C. C.is equal to 1 D. Could be any of the given answers; it all depends on optical density
Last Answer : B. B.is greater than 1
Description : The core of the optical fiber has ______. A. A medium index of refraction B. A lower index of refraction than the cladding C. A lower index of refraction than air D. A higher index of refraction than the cladding
Last Answer : D. A higher index of refraction than the cladding
Description : Is it true that Light travels faster in a material with a higher index of refraction?
Last Answer : Its False
Description : In an optical fiber, the inner coreis _______ the cladding. A) denser than B) less dense than C) the samedensityas D) another name for
Last Answer : denser than
Description : What is the basic optical-material property relevant to optical fiber light transmission?
Last Answer : The index of refraction.
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 : 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 : The index of refraction of a plastic material is 1.5. The speed of light in this material relative to that in a vacuum is: w) 2 x) 1.5 y) 2/3 z) 1/2
Last Answer : ANSWER: Y -- 2/3
Description : An index of refraction less than one for a medium would imply A. That the speed of light in the medium is the same as the speed of light in vacuum B. That the speed of light in the ... greater than the speed of light in vacuum C. Refraction is not possible D. Reflection is not possible
Last Answer : B. That the speed of light in the medium is greater than the speed of light in vacuum
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 : What is the refractive index of optical fiber material ?
Last Answer : The refractive index of optical fiber material is 1.7 .
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 : Optical fiber works on the A. principle of refraction B. total internal reflection C. scattering D. interference
Last Answer : B. total internal reflection
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 : Two methods describe how light propagates along an optical fiber. These methods define two theories of light propagation. What do we call these two theories?
Last Answer : The ray theory and the mode theory.
Description : Optical cable testers are used for ∙ a. Checking refractive index ∙ b. Light power out of a fiber ∙ c. Non-calibrated light into a fiber
Last Answer : b. Light power out of a fiber
Last Answer : ∙ b. Light power out of a fiber
Description : The claddingwhichsurroundsthe fiber core a. is used to reduce optical interference b. is used to protect the fiber c. acts to help guide the light in the core d. ensures that the refractive index remains constant
Last Answer : c. acts to help guide the light in the core
Description : Reduction of Fresnel reflection is possible by reducing the step change in the refractive index at the fiber interface. What material reduces the step change in refractive index at a fiber interface?
Last Answer : Index matching gel.
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 : Which of the following uses a very thin glass or plastic fiber through which pulses of light travel? a. Cat 1 b. Optical fiber c. Twisted pair d. Coax
Last Answer : b. Optical 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 : The index of refraction can be considered: w) a ratio of material thickness between substances x) a ratio of velocities of light in different materials y) a ratio of mass between materials z) to have the units of photons
Last Answer : ANSWER: X -- A RATIO OF VELOCITIES OF LIGHT OF DIFFERENT MATERIALS
Description : The ratio of speed of light in air to the speed of light in another substance is called the a. Speed factor b. Index of reflection c. Index of refraction d. Dielectric constant
Last Answer : c. Index of refraction
Description : The ratio of the speed of light in air to the speed of light in another substance is called ∙ A. speed factor ∙ B. index of reflection ∙ C. index of refraction ∙ D. speed gain
Last Answer : ∙ B. index of reflection
Description : The ratio of speed of light in air to the speed of light in another substance is called the ∙ a. Speed factor ∙ b. Index of reflection ∙ c. Index of refraction ∙ d. Dielectric constant
Last Answer : b. Index of reflection
Description : The speed of light in vacuum "C" divided by the Index of Refraction "N" gives the: w) frequency of the light x) speed of the light in the medium y) energy of the light z) wavelength of the light
Last Answer : ANSWER: X -- SPEED OF THE LIGHT IN THE MEDIUM
Description : Pick up the correct statement from the following: (A) A refracting telescope consists optically of two lenses (B) The principal axes of both the lenses coincide the optical axis of the telescope (C) The lens nearer the object to be viewed is convex and is called objective (D) All the above
Last Answer : (D) All the above
Description : X-ray crystallographic analysis of an optically active compound determines its (A) Optical rotatory dispersive power (B) Absolute configuration (C) Relative configuration (D) Optical purity
Last Answer : (B) Absolute configuration
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 : Quality fiber-end preparation is essential for proper system operation. What properties must an optical fiber-end face have to ensure proper fiber connection?
Last Answer : Be flat, smooth, and perpendicular to the fiber axis.
Description : Which types of LEDs are the preferred optical sources for short-distance, low-data-rate fiber optic systems?
Last Answer : SLEDs and ELEDs.
Description : The amount of optical power coupled into an optical fiber depends on what four factors?
Last Answer : (1) The angles over which the light is emitted. (2) The size of the source's light-emitting area relative to the fiber core size. (3) The alignment of the source and fiber. (4) The coupling characteristics of the fiber (such as the NA and the refractive index profile)
Description : Which part of a fiber optic transmitter converts the processed electrical signal to an optical signal?
Last Answer : The optical source.
Description : Describe an optical fiber cable component (OFCC).
Last Answer : OFCCs are tight-buffer fiber surrounded by arimid yarn and a low-halogen outer jacket.
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 : List the two principal optical detectors used in fiber optic systems.
Last Answer : The semiconductor positive-intrinsic-negative (PIN) photodiode and avalanche photodiode (APD).
Description : If an installed optical fiber cable does not have connectors or terminations on both ends, how should the cable be tested?
Last Answer : With an OTDR unless it is less than 50 meters in length. If it is less than 50 meters in length, continuity should be verified with a flashlight.
Description : When is an optical power meter measurement recommended for conducting field measurements on installed optical fiber cables or cable plants?
Last Answer : When an installed optical fiber cable or cable plant is less than 50 meters in length.
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 : 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 : Does underfilling a multimode optical fiber excite mainly high-order or low-order modes?
Last Answer : Low-order modes.
Description : What are the main causes of absorption in optical fiber?
Last Answer : Intrinsic and extrinsic material properties.
Description : What type of optical fiber operates below the cutoff
Last Answer : The order of a mode is indicated by the number of field maxima within the core of the fiber. The order of a mode is also determined by the angle that the wavefront makes with the axis of the fiber
Description : List the three parts of an optical fiber.
Last Answer : Core, cladding, and coating or buffer.
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