Resultado final:

How to create laser beam effect with the help of Target Direct light.

[1]-Click on the Geometry > Standard Primitives > Box and use the following setting
Create a box in the top view like this

[2]-Click on the Geometry > Standard Primitives > Plane and use the following setting
Set the plane like this in the Perspective view

[3]-Click on the Geometry > Standard Primitives > Teapot and use the following setting
Create a teapot in the top view like this

[4]-Now apply the Shell Modifier and use the following setting your object should be like this

[5]-Now click on the Light > Standard > Skylight and use the following setting ands set the Skylight like this
image as shown below

[6]-Now click on the Light > Standard > Target Spot and use the following setting ands set the Target Spot like this
Image as shown below

[7]-Now press (M) you will see the material window is open create a two material
I can import one map but different uses one for texture map and second for Environment map Image as shown below

[8]-Press the (F12) you will see the render window is open and open Final Gather use the following setting

[9]-press (F9) and you will see the final image is ready save the file in your folder

Fonte: aqui

GG