Laser Pointer Forums - Discuss Laser Pointers | High Power Lasers

I have the laser from a laptop HD DVD drive, but cannot figure out which pin is the positive on it. In the pic the negative is the one in the center on the left, found out with a continuity test. I tried probing the other pins with 3, 4.5, 6, 7.5, and 9v. I would think the center right pin would be my positive, but when probing it, nothing happens. What voltage does it need?