See Odonato

Test Chamber 13: Place portals as shown in the image. Use a portal to move the laser sideways and a time portal to send it into the future. Run through the time portal. Rearrange portals in the future so the laser hits the target.

Test Chamber 14: Travel to the present via a time portal. Summon a reflector cube and position it using portals to direct the laser through the first node. Travel to the future. Use portals to bring a laser into the present through the time portal, ensuring it hits the node. Bring the reflector cube from the future to the present. Position the present reflector cube to hit all three nodes. Travel back to the future to retrieve the future reflector cube, then bring it to the present via a time portal. Position this cube to reflect the laser into the receiver.

Test Chamber 15: Go through the particle field to the left. Place a portal where the laser hits the wall and a time portal on the opposite wall. Travel through the time portal to the future to bypass the particle field. Return to the present using another time portal on the other side. Place a portal on the upper wall to direct the laser to the first receiver. Travel to the future and place a portal on the small wall in the laser room to shoot the receiver. Return to the present. Stand on the elevating platform and place a time portal behind the node to raise the platform further. Summon a reflector cube and place it on the lip above the second receiver. Travel to the future. Retrieve the future reflector cube and bring it to the present via a time portal, positioning it to hit the second receiver through the node. On the other side of the particle field (in the present), climb the stairs and use a portal on the upper wall to hit the third receiver. Move the reflector cube onto the switch to complete the chamber.