Tube?

Ok so this isn't really an electronic question, although it is attached to a luminosity meter.

I search "Google's" all morning, and there is so much crap on the internet, I can't get any valuable info, that makes sense.
I'm hoping that someone here has experience with laser optics.
Here is what I need. A tube or rod, round or square, about a meter long, whatever, that when laser is pointed on the tube at 90 degree angle to the tube's axis, some of the laser beam diverges along the axis of the tube.
Is this possible??
I tried everything I got here, glass stir stick makes nice line generator, and tube does nothing. I tried luminescent fluid and still nothing. Coated inside of tube with white powder(like fluorescent tube), and still nothing. Is this even possible???
Anyone good at physics??
I need some answer today or tomorrow, so my boss can get off my back about this project.

Thanks for any help.

Obviously, an amorphous material like glass won't work. A crystalline or manufactured materal having 45 degree planes is what you need, don't ask me how.

Ok Thanks, now on to google, again.

I'll let you know if I find anything.

Why don't you just use a couple of prisms?
Or something like this link I found on google looking up 90 degree beam splitter
https://www.ligo-wa.caltech.edu/teachers_corner/IFO/Demo.html