It looks to me like you could make a machined version of this by bundling a group of thin walled brass tubes, then soldering them all together. Larger one in the middle to pass the laser, and small ones all around to flow the air. Then it would be pretty easy to turn the bundle to shape on the lathe. If you blocked the end of the large "laser passing" tube with a thin ZnSe window (available from ebay... essentially an IR lens, but flat instead of curved) you could get the effect the article talks about where the center is blocked and the outer tubes provide all of the flow.