On the point of laser weapons being absent, the most prevalent source, in my experience, is church ships of middling size. Other faction ships of similar size/deployment level, tend to get replaced by faction specific encounters(Like freighters for guild). The church end up being the most "standard" in terms of tech vs ship size.
Another sizeable source is space missions. Nearly all space foes excepting zombies are laser armed.
A third source, albeit one time, is the russian files mission. Anyone not the power armor supersoldiers, will generally be laser armed with the occasional Kruger plasma pistol. Mission is however exceedingly difficult. By the point where you can easily accomplish it, nuclear lasers may just be a pointless addendum, compared to the gauss and plasma you may have already.
All that said lasers are largely bad picks compared to conventional weapons, or the more readily available gauss. The eurosyndicate brand does make the cut, barely, for stopping power but are very expensive and gated behind tech RNG, and either a massive -1000 score drain(electing to ignore syndicate hit missions) or very difficult missions that only at best breaks even in score. And the hit missions will keep spawning over and over.
If mercs were not so damn resistant to bullets and incredibly difficult to get close to lasers would not have a useful purpose. Conventional weapons either do more damage per shot, or have useful secondary effects like buttstrike attacks or armor stripping. Even lasers "shtick" armor pen is present in lesser forms on rifles and assorted other things. Outside of mercs i dont use any lasers at all, aside from the occasional fatty to bore through buildings for convenience in late game.
But im probably flaying a long dead equine.