The present invention presents a high-speed electromechanical shutter which has
at least two rotary beam choppers that are synchronized using a phase-locked loop
electronic control to reduce the duty cycle. These choppers have blade means that
can comprise discs or drums, each having about 60 (+/-15) slots which are from
about 0.3 to about 0.8 mm wide and about 5 to about 20 mm long (radially) which
are evenly distributed through out 360, and a third rotary chopper which
is optically aligned has a small number of slots, such as for example, 1 to 10
slots which are about 1 to about 2 mm wide and about 5 to about 20 mm long (radially).
Further the blade means include phase slots that allow the blade means to be phase
locked using a closed loop control circuit. In addition, in a preferred embodiment,
the system also has a leaf shutter. Thus the invention preferably achieves a gate
width of less than about 100 microseconds, using motors that operate at 3000 to
10,000 rpm, and with a phase jitter of less than about 1.5 microseconds, and further
using an aperture with more than about 75% optical transmission with a clear aperture
of about 0.8 mm10 mm. The system can be synchronized to external sources
at 0 6 kHz lasers, data acquisition systems, and cameras.