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Unformatted text preview: disadvantages of using DCM in the transmission. 3. To measure the attenuation coefficient of fiber, a cut-back method in the following apparatus can be employed. A sample of fiber is first installed. The output power is measured to be P 1 (dBm). Then the fiber is cut short on the output part by, say, 50 cm. The output power, P 2 , is measured. (a) Find the fiber attenuation (in dB/km) expressed in P 1 and P 2 . (b) Discuss what may affect the accuracy of this measurement technique for fiber attenuation. 4. Simple answer questions (a) State the pros and cons of using a fiber with large numerical aperture (N.A.). (b) Discuss the effects of reducing fiber core diameter for optical transmission on the power coupling between the laser and fiber, the dispersion, fiber bending loss, dispersion, and others. Laser Fiber under test Lens for power coupling Large Area Optical Power Meter...
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This note was uploaded on 05/18/2010 for the course INFORMATIO IEG 4030 taught by Professor Liank.che during the Spring '10 term at CUHK.
- Spring '10