Edge-emitting Diode: An LED that emits light from its edge, producing more directional output than … Multiple Choice Questions and Answers on Optical Fiber Communication(Part-1).Objective Questions and Answers on Optical Fiber Communication . View Answer, 11. In another scenario when it is required to communicate over long distances where more than one length of fiber cable and other supporting equipment are placed in the system. e. Electron charge. 178. Microstructured optical fibers. See our User Agreement and Privacy Policy. a) BH structures There is some dispersion over long distances. The spectral width determines the number of different wavelengths that are emitted from the LED or laser. In this particular scenario, the optical fiber requires one connection to the transmitter side and another connection at the receiver side. d) Low radiance emission into-fiber This set of Optical Communications Multiple Choice Questions & Answers (MCQs) focuses on “LED Structures”. In optical fiber communication _____ major types of LED structures are used. This fiber type uses a LASER to transmit the signals. Fiber is preferred over electrical cabling when high bandwidth, long distance, or immunity to electromagnetic interference is required. LEDs used as optical fiber transmitters emit infrared radiation at a wavelength of about 850 nm (0.85 µm). Increase B. The cores of the fiberglass & the cladding have a special refractive index to twist inward light at a particular angle. Light Emitting Diodes are the optical sources that made the fiber optic communication possible. Decrease C. Stability D. None of the above. Objective To explore design and operation of optical communication components : light emitting diode (LEDs). Following image depicts a bunch of fiber optic cables. Fiber Optic Communication (2) As the carrier frequency increases, the available transmission bandwidth will increases as well. Pulse code modulated signals from the coder supply input current to the LED. b) High ... ANSWER: (c) Integral lens LED. a) 5.459*10-5 There are 3 main types of lasers in the market today for fiber optic transmitters – VCSELs, FP lasers and DFB lasers. d) To increase current spreading This video describes the properties of optical fiber communication sources. Optical Fiber Communication Multiple Choice Questions :-1. The device or a tube, if bent or if terminated to radiate energy, is called a waveguide, in general. All Rights Reserved. These light sources are small semiconductor devices which efficiently converts electrical signal to light signal. Sanfoundry Global Education & Learning Series – Optical Communications. View Answer, 5. B r. Recombination coefficient [cm 3 s −1] d. Active region thickness. τ LED. SURFACE EMITTING LED’S. The active layer of E-LED is heavily doped with ____________ This process can be explained using a diagram as shown below: Transmitter side: On the transmitter side, first if the data is analog, it is sent to a coder or converter circuit which converts the analog signal into digital pulses of 0,1,0,1…(depending on how the data is) and passed through a light source transmitter circuit… c) High a) Low Developments in LEDs are in parallel to the historical developments in fiber optic communication. a) 1.534*10-6 Properties of optical fiber communication sources (LASER and LED). c) Low current densities The amount of radiance in planer type of LED structures is ____________ b) QC structures • It is a p-n junction diode, which emits light when activated. If you wish to start right away, head over to the optical fiber communication course page. a) Cannot be determined 2. These are the new types of optical fiber cables. b) 1.784*10-3 View Answer, 3. The desirable properties of optical fiber sources like LASERS and diodes have been discussed in this video in detail. a) Zn View Answer. In a multimode fiber, much of light coupled in the fiber from an LED is ____________ A. static fatigue . View Answer, 2. d) 9.551*10-5 Whenever light gestures are transmitted through the optical cable, then they do not reflect the cladding & core within a sequence of zigzag bounces, sticking to a method is named as total internal reflection. If you continue browsing the site, you agree to the use of cookies on this website. An Optical Fiber is a cylindrical fiber of glass which is hair thin size or any transparent dielectric medium. Optical communication reached a peak in the 1800s with the use of the heliograph for signaling during military operations in the American southwest. © 2011-2020 Sanfoundry. c) DH structures a) True b) To increase radiance When the bandwidth becomes larger, it will provides a larger information capacity. Determine the overall power conversion efficiency of lens coupled SLED having forward current of 20 mA and forward voltage of 2 V with 170 μWof optical power launched into multimode step index fiber. c) Zero a) 0.03 Both of them are based around semiconductor technology: Light emitting diodes (LEDs) Laser diodes; Semiconductor optical transmitters have many advantages. View Answer, 15. b) 4.417*102 When a suitable voltage is applied to the leads. 4. d) Coupled optical power 1. – 13ECE06 II.2 Optical Fiber/Cable In this section, we discuss the structure and properties of an optical fiber, how it guides light, and how it is cabled for protection. b) 0.05 Dispersion in optical fibers In an optical medium, such as fiber, there are three types of dispersion, chromatic, modal, and material. 6 μA c. 9 μA A. design of fiber optic communication systems. View Answer, 10. The InGaAsP is emitting LEDs are realized in terms of restricted are ____________ LED StructuresLED Structures yFive majjypor type: y1-Planar LED y2-DomeLEDDome LED y3-Surface emitter LEDs y4-Ed E itt LEDEdge Emitter LEDs y5-Superluminescent LEDs yOnly two have use in OFC(SLED and ELED) C. stress fatigue . The fiber is designed as a step index, meaning that the core has only one refractive index to carry the light signal. 3 μA b. Operating time for a 50% output reduction from an LED. b) Eu Participate in the Sanfoundry Certification contest to get free Certificate of Merit. In the FOC system, the light source like an LED or laser diode is used as a transmitter. a) To reduce radiance Coupling lens used to increase efficiency. View Answer, 7. d) 0.01 The Optical fiber communication processtransmits a signal in the form of light which is first converted into the light from electrical signals and transmitted, and then vice versa happens on the receiving side. Optical Sources suited to Fiber Optic Communication: Light Emitting Diode (SLED, ELED, SLD) Semiconductor Laser (DFB, DBR, Vertical-Cavity Surface- Emitting Laser(VCSEL), Multi Quantum Well, In-Fiber Lasers, Fiber Ring Lasers) d) Unaffected Answer: c Explanation: Optical fiber communication involves the use of 6 different major LED structure. This is very simple optical fiber communication system. c) 3.478*102 c) To reduce current spreading b) Less coupled optical power It provides a canonical statistical description of optical signals, mostly mentioned in the literature of radio and optical communications. 3. The fiber which is used for optical communication is waveguides made of transparent dielectrics. d) 2.826*10-9 The electromagnetic energy travels through it in the form of light. View Answer, 13. The transmitters in optical fiber links are generally light-emitting diodes (LEDs) or laser diodes. View Answer, 9. this slide is about LED and Laser as optical source. a) 2 b) 4 c) 6 d) 3 View Answer. Edge Emitting LED’s. In the types of optical fibers mentioned above, light travels due to total internal reflection and refractive indices of the core and cladding. In this report the role of noise in optical communications, and how it can limit the performance of optical communications systems, will be examined. c) Higher, lesser, increased Which type of mechanical splicing exhibits the permanent bonding of prepared fiber ends with the rigid alignment of the tube? c) 3.564*10-2 Gate syllabus for Computer science and information Technology. Optical fiber communication is one of the fastest communication methods developed by humans. 1. d) Very low It is because of this reason that first and second generation optical communication systems used near parabolic index fibers. Join our social networks below and stay updated with latest contests, videos, internships and jobs! d) 3 Lasers have proven to be ideal light sources because of their high bandwidth capability and narrow spectral output. Generally precision, metallic or plastic connectors, such as SMA, ST, FC/PC connectors, are used for proper alignment between the LED and the optical fiber so as to maximize the power coupled on to the fiber. Chromatic Dispersion Chromatic dispersion results from the spectral width of the emitter. Name – Bhupender singh View Answer, 14. c) 4.25*10-3 d) Sn View Answer, 12. They have an entirely different concept of using light for communication. LED to fiber coupling is a very major issue in optical fiber communication applications employing LEDs. Data rates less than 20 Mbps. a. They are small, convenient, and reliable. View Answer, 6. Now customize the name of a clipboard to store your clips. B. mechanical fatigue . DH surface emitter generally give ____________ If you continue browsing the site, you agree to the use of cookies on this website. D. coating fatigue d) 2.14*10-3 Optical components for communications principles and applications pdf, Advanced optical communication By Er. Types of fibre optic transmitter. For a parabolic index fiber, the pulse dispersion is reduced by a factor of about 200 in comparison to step index fiber. b) 4 The process of communication using fiber optics has the following steps − Conversion of input electrical data to light signals: The data to be sent by the sender is in the form of electrical signals. The macroscopic bending losses show an exponential increase due to _____ in radius of curvature. b) Radiance Mention of both single mode fiber and multi-mode fiber is often seen in the literature. One refractive index to twist inward light at a particular angle and refractive indices of the fiberglass & cladding! Cavity LED, planar LEDs and Dome LEDs complete set of optical can. Current into light practice all areas of optical fiber system LED • a light-emitting diode ( LEDs ) diodes... 0.0375 V. Determine optical power launched into fiber mentioned in the literature f c. diode bandwidth understand everything you... Know about how this technology works larger, it will provides a larger information capacity LED & name! The tube light pulses by the transmitter circuitry using a light source military operations the... Meaning that the core has only one refractive index to twist inward light at a angle. Cavity LED, planar LEDs and Dome LEDs spectral width of the information in the American southwest resonant LED! Which emits light when activated dispersion results from the spectral width determines the number different... Of both single types of led in optical fiber communication fiber and multi-mode fiber is the misfit strain ).. Is 0.8 % and power applied 0.0375 V. 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