I want to retrieve human voice from a conversation happening inside a closed room through the windows. I found a way to do it by passing laser light to the window which reflects back to a photo voltaic cell with the human voice pattern which can then be decoded and the result is the human voice. I want to get this equipment and want to check if I can get the equipment from Digi-key or elsewhere.?
It’s a neat idea that’s easy to understand conceptually and which a person sees in movies and books and such on occasion, but the reality is not so simple. Glass is pretty rigid when thick enough to use as a window, and consequently it doesn’t move much in response to pressure from weak acoustic vibrations such as created by normal conversation. Without significant movement, there’s no significant change in reflection that’s easily detectable with cheap equipment, or for that matter any equipment sold by Digi-Key as ready-to-use goods.
If it’s something you really want to pursue, do some research on laser interferometry and similar techniques. Then maybe enroll at a university or befriend somebody who works in a lab setting with a proper optical table and get something working under controlled conditions, then build from there.