I have used both a 5mw helium neon and a cheapo 3 to 5mw pointer diode laser. The helium neon has been sitting in the closet gathering dust for 8 months. The diode laser has only 5 minutes warm up time, at least 2 feet of coherence length compared to 8 inches with the gas laser. It's smaller, less fragle. Another plus, if your doing single beam holography you can pull the lens off the pointer and the beam diverges with out an extra lens. At least as far as holography is concerned, I think neon helium lasers are going to go the way of vacuum tubes.
Slashdot Mirror
I have used both a 5mw helium neon and a cheapo 3 to 5mw pointer diode laser. The helium neon has been sitting in the closet gathering dust for 8 months. The diode laser has only 5 minutes warm up time, at least 2 feet of coherence length compared to 8 inches with the gas laser. It's smaller, less fragle. Another plus, if your doing single beam holography you can pull the lens off the pointer and the beam diverges with out an extra lens. At least as far as holography is concerned, I think neon helium lasers are going to go the way of vacuum tubes.