Description : One of the following is not a solid-state optical detector ∙ a. APD ∙ b. PIN ∙ c. PMT ∙ d. Phototransistors
Last Answer : . PMT
Description : Which of the following is used as an optical transmitter on the Fiber Optical Communications? ∙ a. APD ∙ b. LSA diode ∙ c. PIN diode ∙ d. LED
Last Answer : d. LED
Description : . Is a non-coherent light source foe optical communications system. ∙ a. ILD ∙ b. LED ∙ c. APD ∙ d. PIN Diode
Last Answer : ∙ b. LED
Description : Which of the following is the fastest light sensor ∙ a. PIN photodiode ∙ b. Photovoltaic diode ∙ c. Phototransistor ∙ d. Avalanche photodiode
Last Answer : ∙ d. Avalanche photodiode
Description : The minimum optical power a light detector can receive and still produce a usable electrical output signal. ∙ A. light responsivity ∙ B. light sensitivity ∙ C. light collectivity ∙ D. illumination
Last Answer : B. light sensitivity
Description : A pn-junction diode emits light by spontaneous emission ∙ A. LED ∙ B. APD ∙ C. PIN
Last Answer : A. LED
Description : Which of the following is used as an optical receiver in fiber optics communications ∙ a. APD ∙ b. Tunnel diode ∙ c. Laser diode ∙ d. LED
Last Answer : a. APD
Description : The term responsivity as it applies to a light detector is best described as ∙ A. the time required for the signal to go from 10 to 90 percent of maximum amplitude ∙ B. the ratio of the diode ... . the ratio of the input power to output power ∙ D. the ratio of output current to input current
Last Answer : the ratio of the diode output current to the input optical power
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 : Which of the following is NOT a common light detector ∙ a. PIN photodiode ∙ b. Photovoltaic diode ∙ c. Photodiode ∙ d. Avalanche photodiode
Last Answer : ∙ b. Photovoltaic diode
Description : APD stands for: a. Avalanche Photodiode b. Advanced Photodiode c. Avalanche Photo Detector d. Advanced Photo Detector
Last Answer : a. Avalanche Photodiode
Description : The three major groups of the optical system are ∙ A. the components, the data rate and the response time ∙ B. the source, the link and the receiver ∙ C. the transmitter, the cable and the receiver ∙ D. the source, the link and the detector
Last Answer : B. the source, the link and the receiver
Description : For a 300-m optical fiber cable with a bandwidth distance product of 600 MHz-km, determine the bandwidth. ∙ A. 5 GHz ∙ B. 1 GHz ∙ C. 2 GHz
Last Answer : C. 2 GHz
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 bandwidth of optical fiber ∙ a. 900M Hz ∙ b. 900 PHz ∙ c. 900 THz ∙ d. 900 EHz
Last Answer : c. 900 THz
Description : The most common device used as a light detector in fiber optic communications system. A. LED B. Darlington phototransistor C. APDs D. PIN diode
Last Answer : C. APDs
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 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 : The _____ of a detector is the fraction of incident photons that produce a photoelectron or electron-hole pair ∙ a. Responsitivity ∙ b. Photon efficiency ∙ c. Aperture ∙ d. Quantum efficiency
Last Answer : d. Quantum efficiency
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 : 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 : 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 : The energy of the photon is ∙ a. Directly proportional to its bandwidth ∙ b. Directly proportional to the Planck’s constant ∙ c. Directly proportional to Boltzmann’s constant ∙ d. Inversely proportional to the Planck’s constant
Last Answer : Directly proportional to the Planck’s constant
Description : The bandwidth of a fiber is limited by ∙ a. Mode ∙ b. Wavelength ∙ c. Dispersion ∙ d. Frequency
Last Answer : c. Dispersion
Description : How many longitudinal modes can fall within a laser’s gain bandwidth? ∙ a. 2 ∙ b. 5 ∙ c. 9 ∙ d. No fixed limit, dependent on bandwidth and mode spacing
Last Answer : ∙ d. No fixed limit, dependent on bandwidth and mode spacing
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 : 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 : An increase in light intensity produces fast optic switching due to ∙ a. Increase in index of glass ∙ b. Amplification of optical signal ∙ c. High gain ∙ d. Photoconductivity
Last Answer : b. Amplification of optical signal
Description : Which of the following is the fastest light sensor? ∙ A. PIN photodiode ∙ B. Photovoltaic diode ∙ C. Photodiode ∙ D. Avalanche photodiode
Last Answer : Avalanche photodiode
Last Answer : D. Avalanche photodiode
Description : Which of the following is used as an optical transmitter on the Fiber Optical Communications? a. APD b. LSA diode c. PIN diode d. LED
Description : Is a non-coherent light source foe optical communications system. a. ILD b. LED c. APD d. PIN Diode
Last Answer : b. LED
Description : A non-coherent light source for optical communications system. A. PIN Diode B. ILD C. APD D. LED
Last Answer : D. LED
Description : Which of the following is not a part of the optical spectrum? ∙ A. infrared ∙ B. ultraviolet ∙ C. visible color ∙ D. x-rays
Last Answer : ∙ D. x-rays
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 : For a single mode optical cable with 0.25 dB/km loss, determine the optical power 100 km from a 0.1-mW light source. ∙ A. -45 dBm ∙ B. -15 dBm ∙ C. -35 dBm
Last Answer : ∙ C. -35 dBm
Description : A type of index of an optical fiber that has no cladding and whose central core has a non-uniform refractive index. ∙ A. graded index ∙ B. multimode ∙ C. single mode ∙ D. step-index
Last Answer : ∙ A. graded index
Description : A type of index profile of an optical fiber that has a central core and outside cladding with a uniform refractive index ∙ A. multimode ∙ B. graded index ∙ C. step-index ∙ D. single mode
Last Answer : ∙ C. step-index
Description : Optical power is sometimes called __________. ∙ A. Radiant emission ∙ B. Radiant power ∙ C. Radiant flux ∙ D. Radiant optics
Last Answer : C. Radiant flux
Description : It is described as the flow of light energy past a given point in a specified time ∙ A. Optical radiation ∙ B. Optical impedance ∙ C. Optical illusion ∙ D. Optical power
Last Answer : D. Optical power
Description : In radiometric terms, it measures the rate at which electromagnetic waves transfer light energy ∙ A. Optical radiation ∙ B. Optical impedance ∙ C. Optical illusion ∙ D. Optical power
Description : Developed an optical fiber with losses less that 2 dB/km ∙ A. Kao and Bockham ∙ B. Maiman, Kao and Bockham ∙ C. Maiman and Schawlow ∙ D. Kapron, Keck and Maurer
Last Answer : ∙ A. Kao and Bockham
Description : The scientist who built the first optical maser ∙ A. Charles Townes ∙ B. GA Bockham ∙ C. Theodore Maiman ∙ D. ACS Van Heel
Last Answer : ∙ C. Theodore Maiman
Description : Approximately what is the frequency limit of the optical fiber? ∙ A. 20 MHz ∙ B. 1 MHz ∙ C. 100 MHz ∙ D. 40 GHz
Last Answer : ∙ D. 40 GHz
Description : Which modulation methods are the most widely used in optical systems? ∙ a. Phase and frequency modulations ∙ b. Polarization modulation and phase modulation ∙ c. Intensity modulation and phase modulation ∙ d. Intensity modulation and polarization modulation
Last Answer : Intensity modulation and polarization modulation
Description : Used to test a fiber optics splice ∙ a. Spectrum analyzer ∙ b. Oscilloscope ∙ c. Optical power meter ∙ d. Field strength meter
Last Answer : c. Optical power meter
Description : What is the frequency limit of an optical fiber? ∙ a. 20 GHz ∙ b. 30 GHz ∙ c. 40 GHz ∙ d. 50 GHz
Last Answer : ∙ c. 40 GHz
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 : Optical detectors are square-law devices because they respond to _____ rather than amplitude ∙ a. Intensity ∙ b. Light ∙ c. Density ∙ d. Photon
Last Answer : a. Intensity
Description : In solid-state optical detectors, the excited charge is transported in the solid by ∙ a. Holes and protons ∙ b. Holes and electrons ∙ c. Anion and cation ∙ d. Protons and photons
Last Answer : ∙ b. Holes and electrons