QBY-4001 / QBY-4010 GaN Pockels cell drivers

QBY-4001 and QBY-4010 are Pockels cell drivers by OEM Tech based on GaN transistors, which provide bipolar voltage pulses (3-4 ns rise/fall) on the outputs to control the birefringence of an electro-optical crystal to change the polarization state of light passing through. The QBY-4001 was designed as a very compact model with fast switch to obtain short pulses starting from 10 ns. The QBY-4010 is equipped with cooling fans, which made it possible to increase the max. rep. rate in ten times at the maximal voltage in comparison with QBY-4001, however the dimension of the system is slightly greater.

It is possible to adjust pulse amplitude by analog input signal and pulse repetition rate and width by external TTL signals J1 and J2 (see the picture below). 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).

The module requires +24 V DC power supply and a pulse generator to set an operating frequency and pulse width.

Please, note that by bipolar 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 module is very sensitive to load 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.