Green Laser Tip Designs

Does anyone know how to design or make a green laser tip (star, square, etc). Any help would be great.
Thanks in advance

Get a book on making Holograms, basically its a film exposed to a split laser beam expanded to illuminate an object, the interference pattern is exposed on film, and after developing, the film is the Hologram. If your subject is an arrangement of reflective ball bearings, then the hologram will show that arrangement like a pattern of tiny lights. -Glenn

I think he means when you pass the laser through a diffraction grating and it makes patterns like stars and squares... I think he is talking about a printed diffraction grating. More info is needed!