Description : Which part of a fiber optic transmitter converts the processed electrical signal to an optical signal?
Last Answer : The optical source.
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 : 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 : 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 : The number of half-wave patterns in the "b" dimension of rectangular waveguides is indicated by which of the two descriptive subscripts?
Last Answer : Second.
Description : The field arrangements in waveguides are divided into what two categories to describe the various modes of operation?
Last Answer : Transverse electric (TE) and transverse magnetic (TM).
Description : What term is used to identify each of the many field configurations that can exist in waveguides?
Last Answer : Mode of operation.
Description : Compared to the velocity of propagation of waves in air, what is the velocity of propagation of waves in waveguides?
Last Answer : Slower.
Description : What is the primary lower-frequency limitation of waveguides?
Last Answer : Physical size.
Description : What is used as a dielectric in waveguides?
Last Answer : Air.
Description : What kind of material must be used in the construction of waveguides?
Last Answer : Conductive material.
Description : List the two common types of waveguides in use today.
Last Answer : Cylindrical and rectangular.
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 : 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 : 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 : 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 : 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 : 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 : List the three parts of an optical fiber.
Last Answer : Core, cladding, and coating or buffer.
Description : The index of refraction measures the speed of light in an optical fiber. Will light travel faster in an optically dense material or in one that is less dense?
Last Answer : Light will travel faster in an optical material that is less dense.
Description : What is the basic optical-material property relevant to optical fiber light transmission?
Last Answer : The index of refraction.
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 : 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 : In 1969, what did several scientists conclude about optical fiber loss?
Last Answer : mpurities in the fiber material caused the signal loss in optical fibers. The basic fiber material did not prevent the light signal from reaching the end of the fiber.
Description : Circuit used to amplify the optical signal in fiber optics communications links. A. Attenuator B. Optical repeater C. Optical amplifier D. Generator
Last Answer : B. Optical repeater
Description : The physical layer provides __________ a. mechanical specifications of electrical connectors and cables b. electrical specification of transmission line signal level c. specification for IR over optical fiber d. all of the mentioned
Last Answer : d. all of the mentioned
Description : The physical layer provides __________ A. mechanical specifications of electrical connectors and cables B. electrical specification of transmission line signal level C. specification for IR over optical fiber D. all of the mentioned
Last Answer : D. all of the mentioned
Description : What specifications does physical layer provides __________. A. mechanical specifications of electrical connectors and cables B. electrical specification of transmission line signal level C. specification for IR over optical fiber D. all of the mentioned
Description : The physical layer provides __________ a) mechanical specifications of electrical connectors and cables b) electrical specification of transmission line signal level c) specification for IR over optical fiber d) all of the mentioned
Last Answer : d) all of the mentioned
Description : Which performance parameter is the minimum amount of optical power required to achieve a specific bit-error rate (BER) in digital systems or a given signal-to-noise ratio (SNR) in analog systems?
Last Answer : Receiver sensitivity.
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 : What effect does noise have on the fiber optic signal?
Last Answer : Noise obscures or reduces the quality of the signal.
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 : Do facial muscles weaken over time if they are used less often, like other muscles of the body?
Last Answer : answer:I don't think that your facial muscles are weak, but rather you are holding tension in them. If they were weak, your face would be sagging, which does happen with age. More likely you ... I often surprise myself by how hard I am clenching my facial muscles before I become conscious of it.
Description : Does strong language ( cursing ) strengthen or weaken an argument/discussion ?
Last Answer : it always takes away from an argument. using words like that in an argument distracts you from the logic you should be using to prove your point. Strong and offensive language does nothing.
Description : I weaken all men for hours each day. I show you strange visions while you are away. I take you by night, by day take you back, None suffer to have me, but do from my lack.What am I? -Riddles
Last Answer : Sleep.
Description : I weaken all people for hours each day. I show you strange visions while you are away. I take you by night, by day take you back, none suffer to have me, but do from my lack.What am I? -Riddles
Last Answer : I am sleep.
Description : Discuss how Curzon striked at the roots of Bengal nationalism to weaken the National Movement. -SST 10th
Last Answer : Lord Curzon, on assuming the office, felt that patriotic nationalism was gaining ground too rapidly. To counter this spirit of nationalism Lord Curzon thought, it would come to no good unless the Hindu ... it to a peaceful demise.' This was the clear motive of Curzon for the partition of Bengal.