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I read that for VLC, they use toggling the LEDs ON/OFF to represent binaries. Why cannot we modulate the visible light like radio waves.
You can modulate the intensity of the light beam---by driving the LEDs with current that has a component proportional to the amplitude of the audio signal. But digital signal transmission can be made more immune to interfering sources, including sunlight.I read that for VLC, they use toggling the LEDs ON/OFF to represent binaries. Why cannot we modulate the visible light like radio waves.
The LED or semiconductor laser can be pulsed on and off with its power supply.Thanks for the link, Berkeman, I wasn't aware we were using those modulation methods in fiber optics. Am I correct in assuming they are still using either the light from the original laser or from another source to mix with/interfere with the signal and perform modulation/demodulation?