Question 20 (4 points) A 15 km optical fiber link uses fiber with a loss of 1.5 dB km-1. The fiber is jointed every kilometer with connectors which give an attenuation of 0.8 dB each. Determine the minimum mean optical power which must be launched into the fiber in order to maintain a mean optical power level of 0.3 uW at the detector. 0 650.30 uW {i} 465.20 uW ('33 202.50 0w {j} 703.00 0w A four-port directional coupler has 60uW optical power launched into port one. The output powers at ports 4, 2, 3 are 0.0025, 18, and 22 uW respectively. Find the split ratio? O 46% O 45% O 42% O 52%A four-port multimode fiber directional coupler has 50 uWoptical power launched into port 1. The measured output power at ports 4,2 and 3 are 0.003, 23.0 and 24.5 UW respectively. Determine the excess loss. 0.45 dB 0.33 dB 0.12 dB 0.22 dBThe mean optical power launched into an optical fiber link is 1.5 mW, and the fiber has an attenuation of 0.5 dB km-l. Determine the maximum possible link length without repeaters [assuming lossless connectors) when the minimum mean optical power level required at the detector is 2 uW. O 30.3 km .5\"). 57.5 km ( t} 70.5 km 50.3 km Question 5 (4 points] The numerical input/output mean optical power ratio in a 1 km, length of optical fiber is found to be 2.5. Calculate the received mean optical power when a mean optical power of 1 mW is launched into a 5 km length of the fiber (assuming no joints or connectors). (g 30.00 \"W if"; 15.50 \"W if"; 20.40 \"W if"; 10.00 \"W The measured optical output powers from ports 2 and 3 of a multimode fiber FBT coupler are 47.0 uW and 52.0 uW respectively. If the excess loss specified for the device is 0.7 dB. Calculate the amount of optical power that is launched into port 1 in order to obtain these output power levels. 90.12 HW 70.33 HW O 100.4 HW 116.3 uW