QBU-BT-series consists of several Pockels cell drivers that differ with output voltage range, max 6.0 kV bipolar (see also How to order? section). 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.
QBU-BT-series is specially designed 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.
Devices are encased and 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 drivers have 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 (< 20 ns) for both pulse edges.
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 burst mode (i.e. for short term operations).
The performance deteriorates for higher load capacitance.
Output:
pull-down scheme
push-up scheme
triggering by an arbitrary external TTL signal
Voltage, high level
regulated, up to 6 kV
1
Voltage, low level
fixed, 0 V
Pulse width
1 us - 1 s (in internal synchronization mode)
200 ns - ∞ (in external synchronization mode)
Maximal repetition rate
up to 100 kHz and higher (load and voltage dependant, see also Performance section) 1
Jitter
10 ns (1 ns in LJ-modification)
Delay time
1 us (100 ns in LJ-modification)
Load capacitance
up to 0.5 nF
1
Environment:
Operation temperature
0 … +40 °C
Storage temperature
-20 … +60 °C
Humidity
0 ... 90%, non-condensing
Other:
Size (LxWxH)
225x200x60 mm
1)
these parameters aren't indepenent and cannot achieve their maximum at the same time
2)
10-90% level, guaranteed at load capacitance 23 pF and below
Voltage modifications
2.4-6.0 kV high voltage adjustment range
2.0-5.0 kV high voltage adjustment range
1.6-4.0 kV high voltage adjustment range
1.2-3.0 kV high voltage adjustment range
0.8-2.0 kV high voltage adjustment range
0.4-1.0 kV high voltage adjustment range
(*) Other output voltages are available on request
Example
2.0-5.0 kV high voltage adjustment range
Low jitter option
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