Laser display shows a number of my smaller lasers in action.

I made this laser table for my 2014 Home Open Day. It has HeNe, violet, green, red lasers and running and NdYAG and nitrogen plus laser galvos not running. This is a lot safer as an unattended display than a lot of separate laser displays with all the safety concerns.
“Continue reading” for more details and photos.
Below is an update on my laser display case, here with in the dark with labels and the beam paths drawn in.
Exiting the case are a hologram of a butterfly, and a line laser which gives interesting effects as you wave your hand through it. There is a green LED driving a Crooke’s radiometer.

Cost? The acrylic cover was $150 but was a left over from a cover I got made for the Belgrade museum Tesla display. The lasers and power supplies were cheap on eBay. Things like the hexagonal mirror and the HV supply for the HeNe laser were from a scrapped photocopier. Nitrogen laser cost was zero. Maybe $500 if I guess at an all up cost.
If I am not in a position to appreciate it, I will donate it to a science museum if they want it where I have 3-4 other running displays.

This display was mounted on perforated board so things can be screwed on in any position with flexibility to add or remove as needed.

A 40 mW blue laser passing through dilute fluorescein in alkalinised water and then on to Rhodamine 6G in alcohol.

An old Helium-Neon laser using a HV supply from a dead photocopier.
My little hand held Blu-ray laser

A Crookes tube will just turn with a 20mW laser and this one is 16mW infrared and 9mW green.

A 10 mW HeNe laser passes though a small holographic element from a small laser pointer. It is held in place exactly by …. duct tape. It then passes to a prism to be deflected through a prism to pass off to the right so the image (a butterfly) can pass externally.

This small red laser is striking a diffraction grating at an angle. If adjusted correctly it gives a concentric hemicircle of dots. Not sure how this work. A combination of diffraction, refraction balanced with reflection I guess.