What is the principle behind Wavelength Division Multiplexing (WDM) in optical communication?
A. Multiplexing multiple wavelengths of light to transmit multiple signals simultaneously
B. Modulating different signals onto different frequencies
C. Combining multiple optical fibers into one
D. Using time slots for different signals
Explanation:
Wavelength Division Multiplexing (WDM) allows the simultaneous transmission of multiple optical signals over a single fiber by using different wavelengths (channels), increasing the capacity of the communication link.