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Sophisticated techniques have been developed for this process by using magnetic carrier waves operating at radio frequencies as well as microwave and millimeter wave frequencies.
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The information source provides an electrical signal to a transmitter comprising an electrical stage which drives an optical source to give modulation of the lightwave carrier.
The transmission medium consists of an optical fiber cable and the receiver.
The optical carrier is modulated by using neither an analog nor digital information signal.
With digital modulation, discrete changes in the light intensity are not obtained.
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