Question

What type of multiplexing is used in optical fiber lines?

(a) Time division multiplexing

(b) Code division multiplexing

(c) Frequency division multiplexing

(d) wavelength division multiplexing

The question was posed to me by my school teacher while I was bunking the class.

Question is from Fly-by-Light Flight Control topic in portion Fly by Wire Flight Control of Avionics

Answer 1

The correct answer is (d) wavelength division multiplexing

The explanation: Fibre optic data transmission use ‘wavelength division’ multiplexing whereby a single fibre can be used to transmit several channels of information as coded light pulses of different wavelengths (or colours) simultaneously. The individual data channels are then recovered from the optically mixed data by passing the light signal through wavelength selective passive optical filters which are tuned to the respective wavelengths. WDM has a very high integrity as the multiplexed channels are effectively optically isolated.