Can I use a cheap red laser pointer to make holograms?
Yes! Almost any of them will work to some degree. If you take the beam and spread it through a lens (or remove the built-in collimating lens to produce a spread beam) and the illumination looks uniform and does not have black lines in it you can probably use it to make a hologram. The Infiniter 200 is a common choice because many have had success with it. The batteries in a red laser pointer don’t last very long. It is quite common for holographers to cut the barrel off the pointer and wire up D-cell batteries in order for the laser to remain at full power longer.
