How is light manipulated into getting 1’s and 0’s in it?

Question

We use different forms of electromagnetic radiation to function lots of forms of technology. For example, Radio waves and Microwaves are commonly used for wireless tech because of their low frequencies which create a much longer range.

But how exactly are 1’s and 0’s put into them?

In: Engineering

Answer 1

0/1 is the same as on/off (amplitude modulation) or green/red (frequency modulation) or up-down/left-right (linear polarization) or clockwise/counter-clockwise (circular polarization), etc…

As long as you can distinguish two different state, you can decide one state is 0 and the other is 1. Note that if you can distinguish between 4 states, then you can transfer 2 bit at a time, etc…