2. A digital optical fiber link employing ideal binary signaling at a rate of 50 Mbps operates at a wavelength of 1.3 um. The detector is a germanium photodiode which has a quantum efficiency of...
2. A digital optical fiber link employing ideal binary signaling at a rate of 50 Mbps operates at a wavelength of 1.3 um. The detector is a germanium photodiode which has a quantum efficiency of 45% at this wavelength. An alarm is activated at the receiver when the bit error rate drops below 10. Calculate the theoretical minimum optical power required at the photodiode in order to keep the alarm inactivated. Comment briefly on the reasons why in practice the minimum incident optical power would need to be significantly greater than this value
2. A digital optical fiber link employing ideal binary signaling at a rate of 50 Mbps operates at a wavelength of 1.3 um. The detector is a germanium photodiode which has a quantum efficiency of 45% at this wavelength. An alarm is activated at the receiver when the bit error rate drops below 10. Calculate the theoretical minimum optical power required at the photodiode in order to keep the alarm inactivated. Comment briefly on the reasons why in practice the minimum incident optical power would need to be significantly greater than this value