You’ll reappear on the platform at the other end of the room. If you look back to the centre of the room, there’s a light bridge running up to the roof, so set your first portal here (the angle will be rather tight from here, but it’s certainly doable).
Now trundle off to your left and hit the red plunger to send two Displacement Cubes over the acid. The bridge should stop both of the Cubes from falling into the acid, so make your way over to both of them (use light bridges as a moving barricade by firing them directly into the ground in front of you, deflecting the turrets shots).
Pick up one of the Cubes and take it over to the laser beam on your left. Stand behind the wall and angle the Cube so it’s passing the beam through the two 'cones' straight ahead.
Now set it down and make your way back to the remaining Displacement Cube. You may need to drop it on occasions so you can set up a light bridge barrier in front of you (to protect you from the turret).
It’s now simply a case of lining up the Cube to deflect the laser into the final 'cone' and over to the beam receptor. This’ll open up the door to the exit, but you still have to get a light bridge to extend from the wall and over to the exit itself.