Electromechanical shutter is used to "open/close" the output opening of a pulsed laser between its 
pulses. This allows you not to "cut he first and the last laser pulse while opening the shutter 
manually.

The shutter itself is made around a solenoid. The driver of the shutter allows not only to open/close 
it but also to let through the shutter a user-defined number of pulses.

The code is here, the schematic is in the subdirectory

Enjoy!