An AOTF is an optically transparent crystal with an acoustic transducer bonded to one of its sides.

A radio frequency (RF) electronic signal is delivered to this transducer, setting up an acoustic wave in the crystal that creates a grating pattern of compressions and rarefactions.

The grating spacing is determined by the RF driving frequency and sets the color of light passed by the filter.

By using multiple RF frequencies, the filter bandwidth and shape can be adjusted at will.

Wavelength switching time is determined by the acoustic speed in the crystal. Including computer control overhead, this is a couple of hundred microseconds.