Another point (more like a long suggestion) :
||There are 3 receptors for the 3 fizzlers from bottom to top. Stack two cubes below the fizzlers, the bottom one facing the direction of the middle and top receptors (both are in the same direction), and the top cube facing the lowest receptor. Make orange portal at the end of tractor beam and the blue one on topmost surface above the fizzlers.
If somehow the laser beam can be vertically redirected through the fizzlers such that it can pass through the two cubes as well, we can proceed as follows :
Stand on the button for the tractor beam, both cubes will go up. The upper one will activate the lowermost receptor, and both cubes will pass through. Place the blue portal on the surface directly below fizzlers, timing it such that the upper cube has touched the mid fizzler and disintegrated. The laser will be coming via the blue portal (vertically), but will be blocked until the upper cube has fizzled completely.
Suspend the remaining cube between the mid and bottom fizzlers by placing the blue portal on top and bottom surfaces in succession with proper timing, until the laser is reinstated. Then allow the cube to go slightly below the mid receptor and immediately make the blue portal on the top surface. It will now pass by the mid and top receptors and also redirect the laser into them, as it is facing them. From there the puzzle is as good as solved...
One big problem... I still haven't figured out HOW to redirect the laser vertically through the fizzlers, or whether it's actually possible||