[Physics] Converting light to infrared

Question

Is there a cheap / simple way of converting visible light source (ordinary white light led) into IR?

My cause is converting light source to IR signal for a universal remote control.

Answer 1

In principle you could convert visible to infrared radiation by shining it onto a perfectly black body. Yet, this would not help for a remote control, as these will most probably use a modulated signal and heating a black body would not be fast enough. Even if you could heat it that fast, it would for sure not cool at the required rate. Therefore your solution will be to directly use an IR LED or a simple circuit using e.g. a phototransistor to modulate an IR LED.