Infrared Variable Output?

I am trying to wire some infrared LEDs to an Arduino. Problem is, the signal from the infrared LEDs has to be able to change variably, like from a potentiometer. What I mean is, I am aware you can read an ouput from an IR LED, then use the Arduino to replicate this and consequently control things, but what if I wanted to ouput a signal that changed, like a potentiometer? Basically, I would like to be able to control some motors speed through PWM by a potentiometer, but wirelessly. I'm not sure if this is possible, and if it is, is there some information I could look into? Any help is greatly appreciated.

iceng4 years ago
The RC integrates the uP PWM  signal to a simple voltage level  which translates to
a variable DC current  through the IR LED  controlling the light intensity. ..

Most IR photo components are built for digital communication like the output displayed in this oscilloscope in this Instructable photo.

You might want to try a DAC and ADC but I think what you are looking for is analog photo components.