In recent years, there has been a lot of interest in coupling sound and light together. Admittedly, we’ve been doing this for a long time, but we’ve always been limited in terms of what we can do with how nature puts materials together. Now, with our ability to construct structures that are the right size, we can make devices that really dance to the tune that we give them.
This control has been demonstrated in a very cute way recently. Researchers have put together micro pillars that convert light into long-lasting, very high-frequency sound waves.
Nature leads the way
Nature, of course, allows sound and light to play together in different ways. For instance, if a gas absorbs light, it will heat up and expand, so flashing a light into a gas will generate a sound wave at the frequency of the flashing. One of the most sensitive techniques for measuring how materials absorb light makes use of this.