Description : Is the width of the range of wavelengths emitted by the light source a. Bandwidth b. Chromatic Dispersion c. Spectral width d. Beamwidth
Last Answer : c. Spectral width
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 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 : 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 : It indicates what signal frequencies can be propagated through a given distance of fiber cable. ∙ A. Bandwidth Distance Product ∙ B. Pulse width dispersion ∙ C. Rise time ∙ D. Cutoff frequency
Last Answer : A. Bandwidth Distance Product
Description : One of the following is not a characteristic of light detectors. ∙ a. Responsitivity ∙ b. Spectral response ∙ c. Transmit time ∙ d. Dispersion
Last Answer : ∙ d. Dispersion
Description : Light rays that are emitted simultaneously from an LED and propagated down an optical fiber do not arrive at the far end of the fiber at the same time results to ∙ A. intramodal dispersion ∙ B. pulse length dispersion ∙ C. modal dispersion ∙ D. wavelength dispersion
Last Answer : D. wavelength dispersion
Description : What parameter of light detector determines the range or system length that can be achieved for a given wavelength? ∙ a. Transit time ∙ b. Spectral response ∙ c. Dark current ∙ d. Responsitivity
Last Answer : ∙ b. Spectral response
Description : What is the spectral width of an ILD? ∙ A. 0.1 nm to 1 nm ∙ B. 2 nm to 5 nm ∙ C. 1 nm to 3 nm ∙ D. 3 nm to 4 nm
Last Answer : C. 1 nm to 3 nm
Description : What is the spectral width of a standard LED? ∙ A. 20 to 40 nm ∙ B. 30 to 50 nm ∙ C. 10 to 30 nm ∙ D. 40 to 60 nm
Last Answer : 30 to 50 nm
Description : The bandwidth of a fiber is limited by ∙ a. Mode ∙ b. Wavelength ∙ c. Dispersion ∙ d. Frequency
Last Answer : c. Dispersion
Description : The range of wavelength values that a given photodiode will respond. ∙ A. spectral response ∙ B. permeance ∙ C. dark current ∙ D. reluctance
Last Answer : A. spectral response
Description : What determines the range of wavelengths over which meaningful data is obtained for calculating the chromatic dispersion?
Last Answer : The wavelength range of the optical source(s) used.
Description : Range of wavelengths of ultraviolet ∙ A. 670 nm to 10^3 nm ∙ B. 440 nm to 540 nm ∙ C. 110 nm to 240 nm ∙ D. 10 nm to 390 nm
Last Answer : D. 10 nm to 390 nm
Description : How can modal dispersion reduced entirely? ∙ A. Use a graded index fiber ∙ B. Use a single-mode fiber ∙ C. Use a monochromatic light source ∙ D. Use a very sensitive light detector
Last Answer : Use a single-mode fiber
Description : Chromatic dispersion is also called ____________________ dispersion.
Last Answer : intramodal
Description : A single-mode cable does not suffer from: a. modal dispersion b. chromatic dispersion c. waveguide dispersion d. all of the above
Last Answer : a. modal dispersion
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 band of light wavelengths that are too short to be seen by the human eye ∙ a. Amber ∙ b. Visible ∙ c. Infrared ∙ d. Ultraviolet
Last Answer : c. Infrared
Description : The band of light wavelengths that are too long to be seen by the human eye ∙ a. Amber ∙ b. Visible ∙ c. Infrared ∙ d. Ultraviolet
Description : A measure of conversion efficiency of a photodetector. ∙ A. Efficiency ∙ B. Responsivity ∙ C. Dark current ∙ D. Spectral response
Last Answer : B. Responsivity
Description : The law that states “When visible light of high frequency electromagnetic radiation illuminates a metallic surface, electrons are emitted” is known as ____________. ∙ A. Einstein law of photon ∙ B. Marconi’s law ∙ C. Maxwell’s law ∙ D. Plank’s law
Last Answer : D. Plank’s law
Description : What is the typical wavelength of light emitted from epitaxially grown LEDs? ∙ a. 840 nm ∙ b. 490 nm ∙ c. 480 nm ∙ d. 940 nm
Last Answer : ∙ d. 940 nm
Description : The first laser emitted ∙ a. Pulses of 694 nm red light ∙ b. A continuous red beam ∙ c. Pulses of white light from a helical flash lamp ∙ d. Spontaneous emission
Last Answer : ∙ a. Pulses of 694 nm red light
Description : The upper pulse rate and information-carrying capacity of a cable is limited by ∙ A. pulse shortening ∙ B. attenuation ∙ C. light leakage ∙ D. modal dispersion
Last Answer : D. modal dispersion
Description : The time it takes a light induced carrier travel across the depletion region of the semiconductor. ∙ A. dispersion ∙ B. response time ∙ C. irradiance ∙ D. transit time
Last Answer : D. transit time
Description : Which of the following is not a factor in cable light loss? ∙ A. reflection ∙ B. absorption ∙ C. scattering ∙ D. dispersion
Last Answer : A. reflection
Description : The term dispersion describes the process of ∙ A. separating light into its component frequencies ∙ B. reflecting light from a smooth surface ∙ C. the process by which light is absorbed by an uneven rough surface ∙ D. light scattering
Last Answer : A. separating light into its component frequencies
Description : The ratio of the speed of light in a vacuum and the speed of light in the material used. ∙ a. S/N ratio ∙ b. Refractive index ∙ c. Intermodal dispersion ∙ d. Monomode ratio
Last Answer : b. Refractive index
Description : Which of the following is not a factor in cable light loss? ∙ a. Reflection ∙ b. Absorption ∙ c. Scattering ∙ d. Dispersion
Last Answer : ∙ a. Reflection
Description : The upper pulse rate and information carrying capacity of a cable is limited by ∙ a. Pulse shortening ∙ b. Attenuation ∙ c. Light leakage ∙ d. Modal dispersion
Last Answer : ∙ d. Modal dispersion
Description : ______ dispersion is caused by the difference in the propagation times of light rays that take different paths down a fiber. ∙ a. Material dispersion ∙ b. Wavelength dispersion ∙ c. Modal dispersion
Last Answer : ∙ c. Modal dispersion
Description : Dispersion is used to describe the ∙ a. Splitting of white light into its component colors ∙ b. Propagation of light in straight lines ∙ c. Bending of a beam of light when it goes from one medium to another ∙ d. Bending of a beam light when it strikes a mirror
Last Answer : a. Splitting of white light into its component colors
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 : The loss in signal power as light travels down a fiber is called ∙ a. Dispersion ∙ b. Scattering ∙ c. Absorption ∙ d. Attenuation
Last Answer : ∙ d. Attenuation
Description : The term single mode and multimode are best described as ∙ A. a number of fibers placed into fiber-optic cable ∙ B. the number of voice channels each fiber can support ∙ C. the number of wavelengths each fiber can support ∙ D. the index number
Last Answer : C. the number of wavelengths each fiber can support
Description : The main benefit of light wave communications over microwaves or any other communications media are ∙ A. lower cost ∙ B. better security ∙ C. wider bandwidth ∙ D. freedom from interface
Last Answer : C. wider bandwidth
Description : The main benefit of light-wave communications over microwaves or any other communications media is ∙ a. Lower cost ∙ b. Better security ∙ c. Wider bandwidth ∙ d. Freedom from interference
Last Answer : c. Wider bandwidth
Description : Which of the following contributes to the broadening of laser emission bandwidth? ∙ a. Doppler shift of moving atoms and molecules ∙ b. Amplification within the laser medium ∙ c. Coherence of the laser light ∙ d. Optical pumping of the laser transition
Last Answer : Doppler shift of moving atoms and molecules
Description : The _____ is equal to the number of electrons emitted per second times the electron charge ∙ a. Intensity ∙ b. Optical power ∙ c. Photocurrent ∙ d. Responsitivity
Last Answer : c. Photocurrent
Description : Which is the proper measurement of average power emitted by a pulsed laser? ∙ a. Energy x time ∙ b. Pulse energy x repetition rate ∙ c. Pulse energy / repetition rate ∙ d. Peak power x pulse length
Last Answer : ∙ b. Pulse energy x repetition rate
Description : The operation of a fiber-optic cable is based on the principle of ∙ A. refraction ∙ B. reflection ∙ C. dispersion ∙ D. absorption
Last Answer : A. refraction
Description : Which type of fiber-optic cable has the least modal dispersion? ∙ A. single-mode step-index ∙ B. multimode step-index ∙ C. single-mode graded-index ∙ D. multimode graded-index
Last Answer : A. single-mode step-index
Description : Reflections in many directions ∙ a. Diffuse reflection ∙ b. Diffraction ∙ c. Scattering ∙ d. Dispersion
Last Answer : a. Diffuse reflection
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 : Modal dispersion is caused by the ∙ a. Dependence of wavelength on index of refraction ∙ b. Dependence of propagation constant on index of refraction ∙ c. Dependence of the propagation constant on the wavelength ∙ d. Dependence of the propagation constant on the mode number
Last Answer : d. Dependence of the propagation constant on the mode number
Description : Material dispersion is caused by the ∙ a. Wavelength dependence of the index of refraction ∙ b. Wavelength independence of the index of refraction ∙ c. Dependence of the propagation constant on the mode number ∙ d. Independence of the propagation constant on the mode number
Last Answer : d. Independence of the propagation constant on the mode number
Description : Which type of fiber-optic cable has the least modal dispersion? ∙ a. Single mode step-index ∙ b. Multimode step-index ∙ c. Single-mode graded-index ∙ d. Multimode graded-index
Last Answer : ∙ a. Single mode step-index
Description : The operation of the fiber-optic cable is based on the principle of ∙ a. Refraction ∙ b. Reflection ∙ c. Dispersion ∙ d. Absorption
Last Answer : ∙ b. Reflection
Description : What type of fiber has the highest modal dispersion? ∙ a. Step-index multimode ∙ b. Graded index multimode ∙ c. Step-index single mode ∙ d. Graded index mode
Last Answer : a. Step-index multimode