2 points of not on this in X-com:EU you do not have to research lasers at all you can skip strait to plasma just like the original. You do have to get plasma via live capture however only for 3 the pistol, light plasma, and plasma rifle. Studying Plasma rifle unlocks research for Heavy plasma, alloy cannon, plasma sniper research. So the requirement for lasers first and the order pistol, rifle, heavy is a big jump in the requirement even over X-com:EU. However that is not to say I oppose this in fact I would like to take if further and say you have to study lasers in the same pistol, rifle, heavy order. It would also be cool to require the destruction of 1 plasma based weapon in order to start laser research as a point of beam weapon concept building. So...
Capture plasma weapon
Study Beam Weapons (destroying 1 plasma weapon of any type, possible selection?)
Laser pistol
Laser rifle
*Laser Cannon (Ship weapon)
*Laser defense (Base structure)
Heavy Laser
Stun Bomb lancher
Live alien capture
Plasma Pistol
Plasma rifle
*Plasma Cannon (Ship Weapon)
*Plasma defense (Base structure)
Heavy plasma
Blaster Launcher (not big deal to make the plasma weapons a prerequisite because there is time to do so before you ever see one) As far as I know in X-com:Eu you just have to complete a battleship mission and study the fusion core, plasma researched or not.
* You could make the ship weapons and defense buildings requirements to, because that forces enough time to make plasma rifles worth using instead of just pushing a head and researching heavy plasma. I would do laser the same for constancy however heavy laser would need a reduced weight to make it more use able in order for it to be an upgrade for laser rifle. ...In my humble opinion.
Generally the idea is to stall heavy plasma until end game, because once you have it the game is pretty much over.