Making a Laser in Cycles - Straight Beam of Light? I am modeling a laser pointer in Blender, but I am not sure how to make the laser's light beam. 

The Spot light comes the closest to what I am looking for, but its starting diameter is 0, and you cannot set the spread amount to less than 1 degree. 
I would like to be able to do this in the Cycles rendering engine if possible.





Edit: I am not trying to see the actual beam of light, like when you shine a laser beam through fog. Rather, I simply want to have the light beam go straight from the laser. So that if you were to shine it at an object up close, the dot would be the same size as if you were to shine it at a object farther away.

Not this:                              But this:

 &nbsp;&nbsp; 

*Laser images from images.google.com
First Solution:

I have a line-laser and a plane-laser node setup.  

For the line-laser:




For the plane-laser:




Second Solution:

Now that you have asked and I tried to remember,
I got a solution that is easier to understend.  

You can get the plane-laser when using
dot-product instead cross-product.
Then higher strength is required.  





Important Edit

Since I answered this, Blender was updated several times, and I had to update my solution also. An important note is that this solution only works with area lights, since the normal is only provided for those. Other light sources are not capable of providing their direction to the node system. I will contact the devs about this, since the normal has no meaning for other lights now, it could contain the direction of the object.

Some artifacts appear near the edge of the area light when using constant strength, therefor a slight adjusment is required. This can also be used with a point light, when the bottom most node is used instead of the geometry normal. For a point light you can actually skip the subtract.



Here is everything nicely organized and nodes grouped: