QBY Pockels Cell Driver on GaN

The QBY drivers are PCB versions of the QBY-BT. They run on 24 V DC. The QBY-4001 was designed as a very compact model with fast switch to obtain short pulses starting from 10 ns. The QBY-4010-C requires a customer's heatsink, the QBY-4010-A is equipped with cooling fans and the QBY-4010-P has a heatsink case, which made it possible to increase the max. rep. rate in ten times at the maximum voltage in comparison with QBY-4001, however the dimension of the systems is slightly greater.

The operating frequency and pulse width can be varyed in working range by user sending pulse controlling TTL signals J1 and J2 (see the picture below) generated by external pulse generator. The output voltage level could be changed by applying a signal voltage to a respective pin.

Output voltage is up to 4 kV, max. rep. rate strongly depends on selected output voltage value and on load capacitance (we recommend therefore to use the shortest possible cables and choose a Pockels cell with lower capacitance). In order to keep its performance close to datasheet values, one needs to minimize the load capacitance, numbers less than 5 pF are appreciated.
Please, note that by this device an output pulse voltage U is formed by applying +U/2 to positive output wire and –U/2 to negative.
The module was designed to work in set-reset scheme when a base voltage level equals to zero. Non-periodic pulses are also possible, set by pulse generator.

The QBY Pockels cell drivers are based on GaN transistors and offer fast transition time for both pulse edges (3-4 ns).

Performance

The table below contains maximum repetition rate in dependence on output voltage and cooling conditions. Other setup parameters – total load capacitance 5 pF, ambient temperature 25 °C:

Higher load capacitance and higher ambient temperature result in derated performance.