Is there a way to focus multiple laser beams into a single more powerful beam?

Sure. We can do it now. But since the wavelength of sound is in the

neighborhood of 620,000 times longer than the wavelength of light,

in order to focus sound into a beam as narrow as you can focus light,

you need a 'dish' that's 620,000 times bigger than the concave mirror

you could use for light.

The 100-inch Hooker telescope on Mt. Wilson has been used to focus laser

light onto the moon. To focus sound into the same size beam, you need a

dish about 978 miles across, with the souind source at its focus.

Just like so many other examples of technology, the science and the math

are bullet-proof and air-tight, and the only thing we're missing is the $$$ .