Acoustic Bessel beams

Acoustic Bessel beams are a type of sound wave that remains focused over a longer distance, unlike ordinary beams that spread out and weaken. They are formed using special devices called transducers that produce a specific interference pattern, creating a central core of intense sound energy with minimal divergence. This allows the beam to maintain its shape and intensity over a greater range, making them useful in applications like precise imaging, targeted therapy, or non-invasive measurements. Essentially, they are focused sound waves that behave like a narrow, stable beam, similar to how a laser maintains its shape over distance.