How can I make and animate a laser beam looking like an HOURGLASS in blender? I need to make a laser beam that when it goes out from its source it looks like an hourglass. The strongest density of the beam is where the beam is more thin (basically where the sand clock is thinner - the middle part). 

Is there a way to do it with particles? If not show me another way, no problem :)



Thanks in advance!
I may have accidentally made what you wanted (maybe). Please correct me if something isn't right:


So I emit particles from the vertices of a circular ngon (so that the particles collide immediately with the edges of the tube).
And the tube is a collider that has a little bit of stickiness, friction and dampening that luckily seems to make the particles to flow nicely outwards as well.
That's about it.

To do this in Blender 2.79:

Add particle system to the green 'emitter' object. Put Lifetime to 250 and Emit from 'Verts':



For the 'hourglass' object, put collision and Stickiness: 2 - Particle Damping: 0.2 - Particle Friction: 0.2:


You can also go to the particle settings and in Render panel set the particles to be the 'Icosphere' object:

Here are the objects as .blend: