Type mechanical with electronic control. Can also be controlled by a micro controller.
Open time 1.5 second, .3 second over the beam waist.
Cost $ 30 excluding the power supply.
Operational voltage 3.3, 5 and 12 volts.
Laser intensity upto 10 W.
There might be many ways to make a mechanical shutter; I used eclipsing technique in which a shutter moves over and across an aperture through which the beam passes. To move the shutter I used an electric motor and a gear box. This method is relatively hard because of the motor timing (build all the electronics is not easy). While working on this I got couple of ideas of achieving the same goal in 1/10 of the work and time: A 6 inches audio speaker with/without a micro controller can be converted in to a shutter (I will use this method if I plan to make a shutter for He-Ne) OR simply an electromagnet with a cantilever can be used as a shutter. The advantages of such a systems are, easy to make and similar in speed to commercially available systems.