Laser lights for Blender Cycles

As long as Blender does not have a specific light type that behaves like a laser (non-dispersive over the distance), I’ve created these shaders for Point and Spot Lights in Blender Cycles (It does not work on Eevee due to its lack of node support for lights), which emulates a laser by maintaining the size of the lighten area constant no how far the emitter is.

It contains two material shaders:

Laser beam

Circular shaped light where you can set the radius of the beam and it will create a non-dispersive light in the -Z direction of the light.

Laser bar

This is a rectangular light which will maintain the size in the X constant over the distance, as the Y axis expands linearly (like a spot light). This is not very realistic (for example, barcode readers are just a normal beam that scans very fast from one side to the other) but I thought it could be useful in certain situations (like the mentioned barcode reader, making it easier to recreate).

Apart from the size, you can adjust, the color and the strength, just like an emission node shader, and also regulate the linear falloff of the light.

TESTED ON BLENDER 2.83 LTS AND 2.91