Lasermetrics Models 1111 and 1112 are the fastest switching Pockels Cell Electro-Optic
Modulators currently available. The Model 1111, a single crystal device and the 1112, a dual
crystal model have demonstrated rise times of 40 picoseconds and 85 picoseconds
respectively. They attain, within a few percent, the maximum theoretical speed possible for
devices of their physical clear aperture.
The Model 1112 operates at one half the voltage required by the single crystal Model 1111 by using two crystals optically in series and electrically in parallel. Both devices are configured to present a 50 Ohm impedance to
the electrical driving pulse.
These Pockels Cells are made from carefully screened KD*P crystals with >98.5%
deuteration, having a computer optimized cylindrical ring electrode geometry. The design
minimizes drive voltage and switching speed and optimizes optical performance. Crystals are
mounted in a rugged aluminum housing sealed with fused quartz windows. The design permits
use of index matching fluid to minimize reflections from internal optical surfaces. This
feature, in combination with high efficiency, multilayer antireflection coatings on the
protective window surfaces, can provide a transmission of efficiency as high as 98%.
The 1111 and 1112 were designed for use as fast shutters for pulse chopping and isolation, and in
modelocked pulse selection systems where only a single picosecond or femtosecond pulse must be
gated from the pulse train. Total optical path length of the 1111 is 15 mm and that of the 1112 is 22 mm,
which minimizes temporal dispersion. The devices find use in many other laser system applications
requiring the ultimate in switching speed. This series is intended for use with pulsed voltages only since the
equivalent electrical transmission line circuit presents a 50 Ohm impedance load to the driving voltage