This purposes of this video are to demonstrate the following: FM Demodulation, optical interference, polarization, acoustic optic modulator (AOM) and to have fun.
and also Doppler shift with light -- very nice and I learn new thing that I do not need DAQ system + software to get back the sound signal -- just use FM radio ! Thank you.
Great demonstration! Thanks! I'd be interested which possibilities I'd have to modify the transported Informotion on it's way to the receiver. Maybe sth like a pockels cell?
It was a standard 80 MHz AOM. Ideally, I would use an AOM in the range of FM Signals for North America. This AOM frequency is slightly below this FM range. Its been a few years and I do not recall the AOM;s make and model.
We wanted to shift the audio signal to a high frequency of 80 MHz. This method makes the audio signal easier to recover and reduces the low frequency noises which may be apparent had the signal be modulated another way. In addition, the optics for setup where readily available in the lab.