I think this is implied, but not obvious to the player. I think you get a decent reputation boost with every nation whenever you finish a research project, you can also sell your alien tech and lasers as much as you like.
It's also implied that your bases' workshops are unparalleled in the world and no factory or team of engineers in the world can produce what you can, but the nations really appreciate the data you've provided on laser weapons and can start pondering on how to go about making them in tiny amounts, like you do, but they'd keep the lasers they make for themselves anyways, just in case, rather then try and sell them to you.
So it's not 'exclusive' technology, per se, it's just so cutting edge and revolutionary that it's beyond the other nations to implement in any meaningful fashion in any relevant time frame. It's like that with any technology.