QBU-BT-series Pockels cell drivers

The QBU-BT-series consists of several benchtop Pockels cell driver models that differ with output voltage range, max 6.0 kV bipolar (see also How to order? section). Please, note that bipolar device produces an output pulse voltage U by forming +U/2 at the positive output wire and –U/2 at the negative.

The main purpose of the QBU-BT driver is to control Pockels cells by applying a fast switching high voltage. The voltage level, operating frequency and pulse width can be selected in working range by user through RS-232 or through the front panel. Triggering is carried out automatically or via a signal from an external device.

The devices have enclosures, so easy for the user to mount, they run on common 100-240 V AC 50/60 Hz, so, you don’t need extra power supply for the driver.

Three different operating modes are possible:

• push-up (= normally off scheme), when a base voltage level equals to zero, triggering is internal
• pull-down (= normally on scheme), when pulses from base bias voltage to ground are generated, triggering is internal
• triggering by an external low voltage arbitrary TTL signal, external synchronization mode.

The fact that the benchtop Pockels cell driver has a big number of settings, allowing an output signal customization in many ways to solve wide range of tasks, makes them very suitable to use in laboratory.

QBU-BT-series is based on MOSFET technology and offers high repetition rates and fast transition time (< 15 ns) for both pulse edges.

There is a version with SMA-type output connectors only for low voltage versions of the product (1500V and below) available, suitable for driving of unipolar Pockels cells of low capacitance (e.g. EO phase and amplitude modulators). In this version, 1000V voltage set point means that +500V (relatively to the ground) will be delivered to HV+ SMA connector and -500V (relatively to the ground) will be delivered to HV- SMA connector. One connector or both can be used at the same time. 23pF maximum load capacitance can be connected to HV+ and/or HV- connectors.

Performance

In internal synchronization mode the QBU-BT-series (from QBU-BT-1004 to QBU-BT-6024) performance is limited to values given in a table below. The total capacitive load of Pockels cell and connective cable is assumed to be 23 pF (this corresponds to 50 cm output cable bent in non-optimal way and higher than normal Pockels cell capacitance).

Even higher performance can be achieved in external synchronization mode and/or in a burst mode (i.e. for short term operations).

The performance deteriorates for higher load capacitance.

Please, also take a look at other our Pockels cell driver series, for example:

• up to 10 kV benchtop Pockels cell driver QBU-BT-10kV
• up to 6 kV board QBU-series

QBU driver without case	Benchtop Q-switch driver	Compact driver, up to 4 kV