Description : Single frequency light is called ∙ A. pure ∙ B. intense ∙ C. coherent ∙ D. monochromatic
Last Answer : D. monochromatic
Description : Single-frequency light is called ∙ a. Pure ∙ b. Intense ∙ c. Coherent ∙ d. Monochromatic
Last Answer : d. Monochromatic
Description : ____ is a light that can be coherent ∙ a. Spontaneous emission ∙ b. Monochromatic and in-phase ∙ c. Narrow beam divergence ∙ d. Monochromatic
Last Answer : ∙ b. Monochromatic and in-phase
Description : Laser light is ______ emission. ∙ a. Coherent ∙ b. Stimulated ∙ c. Spontaneous ∙ d. Coherent and stimulated
Last Answer : ∙ d. Coherent and stimulated
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 : . Is a non-coherent light source foe optical communications system. ∙ a. ILD ∙ b. LED ∙ c. APD ∙ d. PIN Diode
Last Answer : ∙ b. LED
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 Laser is a beam of radiations which are – (1) Non-coherent and monochromatic (2) Coherent and monochromatic (3) Non-coherent and non-monochromatic (4) Coherent and non-monochromatic
Last Answer : (2) Coherent and monochromatic Explanation: Laser, an acronym for Light Amplification by Stimulated Emission of Radiation, creates a radiation beam that is coherent (in-phase). In a coherent light ... results in a radiation beam of great intensity. It normally produces only one or two wavelengths.
Description : The Laser is a beam of radiations which are (1) Non-coherent and monochromatic (2) Coherent and monochromatic (3) Non-coherent and non-monochromatic (4) Coherent and non-monochromatic
Last Answer : Coherent and monochromatic
Description : Which light emitter is preferred for high-speed data in a fiber-optic system? ∙ A. incandescent ∙ B. LED ∙ C. neon ∙ D. laser
Last Answer : D. laser
Description : They wrote a paper describing how it was possible to use stimulated emission for amplifying light waves (laser) as well as microwaves (maser). ∙ A. Theodore Maiman ∙ B. KC Kao and GA Bockham ∙ C. Charles Townes and Arthur Schawlow ∙ D. Kapron, Keck and Maurer
Last Answer : C. Charles Townes and Arthur Schawlow
Description : Coherence of laser light is important for _________ ∙ a. Light propagation ∙ b. Getting laser light to pass through air ∙ c. Drilling holes ∙ d. Holography
Last Answer : d. Holography
Description : What is used to block light from a laser and let other light through ∙ a. Neutral density ∙ b. Color ∙ c. Interference ∙ d. Spatial
Last Answer : ∙ c. Interference
Description : Which light emitter is preferred for high speed data in a fiber-optic system ∙ a. Incandescent ∙ b. LED ∙ c. Neon ∙ d. Laser
Last Answer : ∙ d. Laser
Description : The laser frequency when the light has the wavelength 800 nm is ∙ a. 375 x 1012 Hz ∙ b. 475 x 1015 Hz ∙ c. 375 x 109 Hz ∙ d. 375 x 1018 Hz
Last Answer : d. 375 x 1018 Hz
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 : Which laser emits light in the visible range 400 to 700 nm? ∙ a. Argon-ion ∙ b. Nitrogen ∙ c. Carbon-dioxide ∙ d. Neodymium-YAG
Last Answer : a. Argon-ion
Description : A dielectric waveguide for the propagation of electromagnetic energy at light frequencies ∙ a. Stripline ∙ b. Microstrip ∙ c. Laser beam ∙ d. Fiber optics
Last Answer : d. Fiber optics
Description : What generates a light beam of a specific visible frequency? ∙ a. Laser ∙ b. Maser ∙ c. Infrared ∙ d. Flashlight
Last Answer : ∙ a. Laser
Description : Human laser was developed by A. Javen at Bell laboratory in ∙ a. 1960 ∙ b. 1962 ∙ c. 1963 ∙ d. 1964
Last Answer : a. 1960
Description : Which type of laser is the simplest to modulate directly by changing its excitation? ∙ a. Semiconductor ∙ b. Ruby ∙ c. Helium-neon ∙ d. Neodymium-YAG
Last Answer : a. Semiconductor
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 : Which of the following factor does not harm laser efficiency? ∙ a. Atmospheric absorption ∙ b. Excitation energy not absorbed ∙ c. Problems in depopulating the lower laser level ∙ d. Inefficiency in populating the upper laser level
Last Answer : ∙ a. Atmospheric absorption
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
Last Answer : Semiconductor
Description : Which of the following colors is not found in the visible light wave spectrum? ∙ a. Red ∙ b. White ∙ c. Orange ∙ d. Yellow
Last Answer : b. White
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 : Lasers are used to produce a) Intense beam of visible light b) monochromatic beam of visible light c) coherent beam of visible light d) All of them
Last Answer : d) All of them
Description : Interference pattern is observed in wedge-shaped film for monochromatic light. Now monochromatic light is replaced by white light. What will be the effect on interference pattern? (a) It will turn to dark (b) It will turn to bright (c) Bands will disappear (d) It will be a mixture of all colors
Last Answer : (d) It will be a mixture of all colors
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 : Laser is a device to produce - (1) a beam of white light (2) coherent light (3) microwaves (4) X-rays
Last Answer : (2) coherent light Explanation: In physics, two wave sources are perfectly coherent if they have a constant phase difference and the same frequency, and the same waveform. Coherence is an ideal property of waves that enables stationary (i.e. temporally and spatially constant) interference.
Description : Laser is a device to produce (A) Gamma rays (B) Microwaves (C) A beam of white light (D) A beam of coherent light
Last Answer : Option B
Description : Which type of fiber optic cable is best for very high speed data? ∙ 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 : Which type of fiber-optic cable is the best for very high speed data? ∙ 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 : Refraction is the ∙ A. bending of light ∙ B. reflection of light waves ∙ C. distortion of light waves ∙ D. diffusion of light waves
Last Answer : A. bending of light
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 : 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 speed of light in plastic compared to the speed of light in air is ∙ A. less ∙ B. more ∙ C. the same ∙ D. zero
Last Answer : A. less
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 : Total internal reflection takes place if the light ray strikes the interface at an angle with what relationship to the critical angle? ∙ A. less than ∙ B. greater than ∙ C. equal to ∙ D. zero
Last Answer : ∙ B. greater than
Description : A popular light wavelength fiber-optic cable is ∙ A. 0.7 micrometer ∙ B. 1.3 micrometer ∙ C. 1.5 micrometer ∙ D. 1.8 micrometer
Last Answer : B. 1.3 micrometer
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 : 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 : 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 : The leakage current that flows through a photodiode with no light input ∙ A. dark voltage ∙ B. dark impedance ∙ C. dark power ∙ D. dark current
Last Answer : D. dark current
Description : A pn-junction diode emits light by spontaneous emission ∙ A. LED ∙ B. APD ∙ C. PIN
Last Answer : A. LED
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 : As light is coupled in a multiport deflective device, the power is reduced by ∙ A. 1.5 dB ∙ B. 0.1 dB ∙ C. 0.5 dB ∙ D. 0.001 dB
Last Answer : C. 0.5 dB
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