Beat phenomenon between AM light beams

We present an interesting case of beat phenomenon which involves light waves and electrical signals. The beat is produced when two amplitude-modulated (AM) light beams are incident on a solar cell. Two smartphones are used as signal generators. These mobile phones are connected in series to two LED lamps and to a set of batteries. Each lamp includes a panel with 24 LEDs. The AM beams from the lamps are incident on a solar cell which is connected to a third mobile phone used as an oscilloscope. The signals are taken out and in the smartphones through the audio port by using audio jacks. More information: https://arxiv.org/pdf/2501.02251