Is there any lifeform that needs it? With light sensors that basically give us line-of-sight range, I don't see which problem organic lasers would solve.
What single-mode lasers do offer is a means of inconspicuous communication. If you can aim your communications channel at a receiver, you cannot easily be detected.
But life could do similar things with collimating reflectors, even for sound. Are there organisms that use geometry to shape sound to send a signal? I'm only aware of ones that use geometry to boost/tune their reception (e.g. owls).
Technically yes but what I mean is: Are there organisms that shape that sound into a tightly focused beam, to be able to only address the receivers they aim at?
I’m being lazy here, but isn’t this what happens when you cup your hands over someone’s ears to whisper? Or ever just turn to the person and talk quietly.