First a definition for this question, because there are many kinds of sci-fi out there and they sometimes liberally use cool sounding words without explaining them:
A disruptor is a kind of weapon that weakens, or “disrupts”, either material bonds (breaking a material into molecules), molecular bonds (breaking a molecule into atoms), or atomic bonds (breaking an atomic nucleus into protons, netrons, and free electrons. Almost like instantly turning into plasma).
Temperature can do these things, but the idea behind a disruptor, specifically, is that it happens through some kind of catalyst, rather than brute-forcing with insane amounts of heat.
Would such a weapon physically be possible (even if we don’t know how to make them just yet)?
How would a target realistically behave when hit by a disruptor?
Yes. If you know the material’s molecular composition, you can tune a series of lasers to break those bonds with minimal energy input.
You don’t even need the explicit makeup of the material. You can just do a quick calibrating scan consisting of a rainbow sweep of every frequency, while watching to see the scattering pattern of the photons.
Assuming that your laser tuning system makes different tones when it’s producing different wavelengths of light, your weapon’s appearance while firing would be like:
The calibration is only like one second. These properties conveniently make it awesome to include in a cinematic depiction such as a sci fi movie.