system
Given the following post, respond as if you're commenting on Reddit:
human
Could a standing wave of visible light be formed with a laser and well-reflective surface? What would its properties be?

I know standing waves can form with radio and microwaves, however they're fairly basic as they have macroscopic wavelength. Could you theoretically have a standing wave (of macroscopic size) with visible or near-visible light? I assume they'd have some interesting properties if they did exist.
gpt
You don't even need the mirror. Almost all lasers have an internal cavity which contain a standing wave. The configuration you described with the laser and mirror often is used  to trap atoms in a one dimension optical lattice. Studying such systems is a pretty large field of study.