Fiber Optics Exam Questions With Accurate Answers

What are the two basic types of fiber? - Answer - Multi-mode - Single-mode What are the three parts of an optical fiber? (Hint, 3 C's) - Answer - core - cladding - coating The North American Standard core sizes for multimode fiber are ____ and ____. - Answer - 52.5 microns - 50 microns The core size for Corning single-mode fiber is ____. - Answer - 8.2 - 8.3 microns The cladding size for both single-mode and multimode fiber is ____. - Answer - 125 microns What invention in 1950's made fiber optics more fasible? - Answer - lasers Index of refraction = speed of light in ____ divided by speed of light in ____. - Answer - a vacuum - a medium As the index of refraction increases, the speed of ligt in a medium ____. - Answer - decreases In what portion of the fiber does light travel the fastest? - Answer - cladding The principle of operation, which permits propogation of light in an SM fiber, is known as ____. - Answer - Total internal reflection The loss of optical power is referred to as ____. - Answer - attenuation What are the two types of attenuation? - Answer - extrinsic - intrinsic Which type of attenuation is diue to traits within the fiber? - Answer - intrinsic Which type of attenuation can be caused by the cable installer? - Answer - extrinsic What are the two types of extrinsic attenuation? - Answer - macrobending - microbending What type of bending is due to tight tie-wraps? - Answer - microbending What type of bending is due to exceeding the bend radius? - Answer - macrobending What is dispersion? - Answer - The spreading of light with respect to time as it travels down the fiber Why can dispersion be a problem in multi-media fiber? - Answer - Due to there being many pathways for the light to travel, and therefore the differing speeds at which the light may travel through each of them, the number of light pulses in an interval is limited. What type of dispersion affects single-mode fiber? - Answer - Chromatic Dispersion - Described as a combination of waveguide and material dispersions. What is bandwidth? - Answer - information carrying capacity What is the bandwidth of single-mode fiber? - Answer - none. - The limit is unspecified due to our equipment's inability to reach said limit. What are two optimal wavelengths used in a multmode system? - Answer - 850nm - 1300nm What are the two optimal wavelengths used in a single-mode system? - Answer - 1310nm - 1550nm A 3dB loss in power is a ____ loss in power. - Answer - 50% Why is 1303nm an optimum wavelength for single-mode? - Answer - 1310nm is the zero dispersion wavelength