Electro-Optic Q-Switch Driver

  • Update:Nov 13, 2018
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STQBD is the series of high repetition rate Pockels cell drivers allowing simple and reliable operation of Q-witched lasers at attractive prices and easy operation.

Product Introduction

SGH Q-D​RIVETM 551 POCKELS CELL DRIVER

The SGH Q-DriverTM is designed for use in product development, teaching and research laboratories. The unit is ideal for evaluating G&H’s OEM driver technology as both drivers share the same electronic design.

Housed in a compact 100x125x50 mm (5x5x2”) aluminium case, the driver has a full suite of controls, indicators and remote control features. It operates form an external 24VDC source (power adapter included).

A unique feature of the driver is its differential bipolar output-reducing voltage to ground and shock hazard, as important feature in a laboratory environment. Leads to the pockels cell leave from the back of the case, keeping them away from hands at the front panel. The driver outputs are short-circuit proof.

The driver is designed for reliability with low component stresses, the highest quality components and the use of US Navy derating standard.

An OEM version with the same electrical performance is available for inclusion in the laser product.

Features:

Benefits

Applications

Ideal for development of Q-switched lasers for:

Specifications

Parameter

Conditions Min Max Units
OUTPUT PULSE PARAMETERS
Pulse top 4kV output, 6pF cell capacitance   150 (nom) ns

Delay time constant

4kV output, 6pF cell capacitance   5 (nom) μ
Pulse voltage Limits of adjustment 1.5 4.5 kV
Load capacitance     25 pF
POWER REQUIREMENTS
24 VDC Power limit before output fold-back   130 mA
TRIGGER 
Trigger voltage   2 8 V
Input Impedance   48 52 ohms
Pulse width   200   ns
Jitter, trigger to output 2ns trigger rise time, Tektronix 11801   20 (nom) Ps RMS
ENVIRONMENTAL
Temperature   -20 50 °C

                             Typical performance Complimentary ± output Risetime -4kV, 10 pF

SGH Q-DRIVETM OEM POCKELS CELL DRIVER

The SGH OEM Q-DriveTM is a cost effective, high performance Pockels cell driver for incorporation into Q-switched laser systems.

The driver is packaged on a compact 100x83 mm (4x3¼") circuit board. The driver is fully self-contained with the power supply and all control circuitry, needing only 24 VDC and a trigger signal to operate.

Designed for reliability with low component stress and worst-case design margins, the driver meets specifications from 40C to +70C. It works with loads to 50 pF.

G&H can supply the driver in different form factors for high volume applications. For more information please see the Design-In Manual.

Features

Benefits

Applications

Specifications

Parameter

Conditions Min Max Units
OUTPUT PULSE PARAMETERS
Pulse top 4kV output, 6pF cell capacitance   150 (nom) ns
Delay time constant capacitance   4kV output, 6pF cell    5 (no)m μ
Pulse voltaget Limits of adjustmen 1.5 4.5 kV
Load capacitance     25 pF

POWER REQUIREMENTS

24 VDC Power limit before output fold-back   130 mA
TRIGGER
Trigger voltage   2 8 V
Input Impedance   48 52 ohms
Pulse width   200   ns
Jitter, trigger to output 2ns trigger rise time, Tektronix 11801   20 (nom) Ps RMS
ENVIRONMENTAL
Temperature   -20 50 °C

                             Typical performance Complimentary ± output Risetime -4kV, 10 pF

 

Layout Dimension

 

SGH R200TM OEM POCKELS CELL DRIVER

The SGH R200TM is a compact OEM Pockels cell driver for inclusion in regenerative amplifiers and other pulse selection applications in solid state laser systems.

The unit drives Pockels cells at 1/4 wave producing pulses at up to 2.5 kV and up to 200 kHz, with burst mode capability to 1 MHz. The driver produces a top-hat waveform with fast rising and falling edges.

Heat load and space requirements are kept at a minimum due to the use of external power supplies.

The trigger input is also electrically isolated from the power supplies for safety.

The compact 115x90x30 mm (4.5x3.5x1.2") circuit board is supplied on an aluminium plate for convection cooling, which can also be attached to a cold plate for water cooling.

The R200 can also be supplied as a turn-key integrated 19” rack system for benchtop use.

Key Features

Benefits

Applications

Specifications

Parameter 

Conditions  Min   Max Units
OUTPUT PULSE PARAMETERS
Pulse repetition rate  Convection cooled    0 40 kHz
Water cooled 1.5 L/min. 40   200  kHz

Pulse voltage

External HV: ±625 VDC in for 2.5kV out    0 2.5 kV
Pulse width  Same as trigger input    250   3,000  ns
Rise, fall times

2.0 kV, 6 pF  

  6.0 ns
2.0 kV, 40 pF max load       9.5 ns
POWER REQUIREMENTS
Input voltage, current  24 VDC (± 2 VDC)     200  mA

High voltage, current 

2.5 kV out, ±625 VDC in, 200 kHz, 6 pF 

  55   mA
TRIGGER
Trigger amplitude Input  Nom. 5 V, 50Ω Impedance    4 10   V
Trigger to output delay  5 V trigger     40   ns
Trigger pulse width    Sets output pulse width 250   3,000  ns

Jitter, trigger to output 

2 ns trigger rise time, Tektroni 11801 

  20 (nom) ps RMS
ENVIRONMENTAL
Mounting surface*     50 °C

*Mounting plate should be attached to a thermally conductive surface for cooling or to a cold plate for water cooling.

Layout & Dimension

SGH QDP-50TM OEM POCKELS CELL DRIVER

The SGH QDP-50TM is a compact OEM Pockels cell driver for inclusion in flash lamp pumped lasers.

The driver is designed for Q-switching of lasers without the need for phase retardation plates. Once triggered, high voltage is applied to inhibit the laser output. After a preset delay, the Pockels cell is opened by a fast negative pulse to allow laser output, then it returns to high voltage to inhibit additional lasing.

The QDP-50 has been shown to increase Pockels cell life expectancy and laser output power relative to voltage-on scenarios often employed.

It can be triggered via an SMA connector or via an optional optical input for greater noise immunity.

The compact 140x92x32 mm (5.5x3.6x1.2") circuit features an integrated high voltage power supply which includes remote voltage monitoring (1 V/kV) and remote shutdown.

Key Features

Benefits

Applications

Specifications

Parameter

Conditions Min Max Units
OUTPUT PULSE PARAMETERS
Pulse repetition rate   Same as trigger input 50  Hz
Amplitude (V1+V2) Adjustable (V2 = 10% of V1)    1.2  4.0 kV
Total HV on time Adjustable or fixed 300  600 μs
Delayed center pulse  Adjustable (range can be modified)   160  200 μs
Rise time    3.5 kV, 6 pF  1 5 μs
Fall time  3.5 kV, 6 pF   < 10  ns
Load capacitance  With Pockels cell leads      30 pF
POWER REQUIREMENTS
Input voltage  Exceeding 20 VDC will damage driver   15  18 VDC
Input current  4.0 kV, 50 Hz, 10pf load    250 mA
TRIGGER
Input impedance      Nom. 50 Ω 48 52 ohms
Amplitude      Nom. 5 V 4 10 V
Pulse width  Set by user 100n  10m  sec
Propagation delay After trailing edge of trigger 80  100 ns
ENVIRONMENTAL
Ambient air temperature     50 °C

 

SGH HVR-DRIVETM POCKELS CELL DRIVER

The SGH HVR-DriveTM is designed to switch Pockels cells used for pulse management in high repetition rate ultrafast laser regenerative amplifiers.

The HVR-Drive can drive Pockels cells at 1/4 λ or 1/2 λ up to 7.5 kV and up to 200 kHz. The driver produces a top-hat waveform with fast rising and falling edges.

Heat load and space requirements are at a minimum due to the use of external power supplies and control electronics.

The HVR-DriveTM measures 136.5x178x70 mm (5.375x7.0x2.8“) with the standard heat sink for convection cooling. It can also be air-cooled or water-cooled for higher repetition rates.

G&H can supply the driver in different form factors for high volume applications. On/Off trigger inputs can be standard TTL signals or optional optical trigger inputs can be supplied.

We can work with you to customize the driver for your specific application. Options such as remote monitoring, remote shutdown and over temperature indicators can be supplied.

Key Features

Key Benefits

Applications

Specifications

Parameter

Conditions Min Max Units
OUTPUT PULSE PARAMETERS
Repetition rate 7.5 kV, 10 pF, water cooled²   100 kHz
6.0 kV, 10 pF, water cooled    150  kHz
5.0 kV, 10 pF, water cooled    200 kHz
Duty cycle  Ratio of pulse width to period (1/frequency)    20 %
Pulse amplitude      1.0 7.5 kV
Rise/fall times      10 15 ns
POWER REQUIREMENTS
Low voltage supply    15.0  18.0 VDC
Low voltage supply  200 kHz rep rate     300 mA
2 x high voltage supplies   For 7.5kV out, external ± 1875 VDC required¹   100 mA
TRIGGER
On/Off trigger voltage    Normally 5 V, TTL 15 V
Trigger to output delay  5 V trigger     60 ns
Pulse width  (subject to 20% duty cycle maximum) 250  3000 ns
Jitter, trigger to output  2 ns trigger rise time    50 ps
ENVIRONMENTAL
Operating ambient   0 50 °C

NOTES

Two external high voltage power supplies are required; one positive output, one negative output.

For example, to achieve 6 kV output you will need ±1500 VDC input.

  1. High voltage current requirements are determined by the pulse width and repetition rate. Rise and fall times vary with output voltage; higher voltages produce longer rise and fall times.
  2. Convection cooled, the maximum rep rate is 25 kHz @ 7.5 kV, 37.5 kHz @ 6 kV and 50 kHz @ 5 kV. Water cooled, chiller set to 24°C, flow rate to 1.5 gal/minute (6L/min) nominal.

CAUTIONS

Do not connect the outputs to ground or damage to the driver will occur.

The low voltage supply must be on before applying the high voltage inputs.

The On/Off triggers must not overlap or damage to the driver will occur.

 

SGH HVR-SYSTEMTM

The SGH HVR-SystemTM is a turn-key integrated driver and control system to switch Pockels cells used for pulse management in high repetition rate ultrafast laser regenerative amplifiers.

The HVR-SystemTM can drive Pockels cells at 1/4λ or 1/2λ up to 7.5kV and up to 200 kHz. The driver produces a top-hat waveform with fast rising and falling edges. The HVR-SystemTM operated from any 88-264VAC, 50-60Hz input, it requires only an AC source and a TTL signal to operate.

A built-in digital voltmeter allows you to set the output voltage before applying it to the driver and separate high voltage enable/disable buttons are standard for added safety. A separate trigger on/off switch provides easy pulse control which also disables the high voltage at the rear panel output connectors.

The HVR-SystemTM comes in a standard 483mm (19”) rack mount enclosure which can also be used as a benchtop unit. It comes with forced air cooling for operation up to 50 kHz or water-cooled for higher repetition rates.

We can work with you to customize the system for your specific application. Option such as optical triggering, remote control and over-temperature indicators can be supplied.

Key Features

Key Benefits

Applications

Specifications

Parameter

Conditions Min Max Units
OUTPUT PULSE PARAMETERS
Max pulse repetition rate Air cooled   50 kHz
  Water cooled   200 kHz
Max duty cycle Ratio if pulse width to period (1/freq)   20 %
Pulse amplitude   1.0 7.5 kV
Rise/fall times 6-10 pF output capacitance¹ 10 15 ns
POWER REQUIREMENTS
Input voltage   88 264 mA
Input frequency   50 60 Hz
TRIGGER
Voltage Normally 5 V, 50 Ω input impedance 4 6 V
Trigger to output delay 5 V trigger   100 ns
Pulse width maximum) (subject to 20% duty cycle 250 3000 ns
ENVIRONMENTAL
Operating ambient   0 40 °C

1 Unit has been tested with up to a 100 pF load and demonstrated rise/fall times less than 40 ns

Standard Output Configurations

Amplitude

Maximum rep rate Model number Cooling method
0-6 kV 10 kHz HVR-60010 Air
0-6 kV 30 kHz HVR-60030 Air
0-6 kV 150 kHz HVR-60150 Water
0-7.5 kV 5 kHz HVR-75005 Air
0-7.5 kV 10 kHz (0-6 kV @ 20 kHz HVR-75010 Air
0-7.5 kV 100 kHz (0-5 kV @ 20 kHz HVR-75100 Water

 

STHVSW-03 OEM Drivers

HVSW03 is a specialized Pockels cell driver that performance is optimized for pico- and femtosecond lasers. Main applications are pulse picking and regenerative amplifier control.

Maximal output voltage is 2kV; maximal repetition rate achieves 1MHz at 1.5kV output voltage and 2MHz at <1.0kV output voltage.

Transition times are as fast as 5-7ns in dependence on load capacitance and driver’s configuration. Pulse width is <15ns (fixed), then 100-2000ns (adjustable by the customer).

Interfaces are analogue and RS-485. Configuration software for Windows® 7 is available.

Compact design (about 0.3dm3), conductive cooling through the bottom surface and embedded high voltage power supply (i.e. driver’s input is +24V DC) are additional benefits.

Specifications

Input 

+24V DC; 5.5A max

Output Pulses of high voltage and high repetition rate delivered to the capacitive load (e.g. to the Pockels cell)
Output type  Bipolar
Pulse basement ¹ 0V, fixed
Pulse amplitude ¹·² adjustable in 0-2kV range
Maximal repetition rate ²  Up to 1-2MHz (see also Performance section)

Minimal repetition rate

Single shot (there is an internal re-striking circuit which makes the operations at such a low repetition rate possible)
Pulse width Fixed, about 15ns in Fixed pulse width mode
100ns-2000ns adjustable (customable) in Variable pulse width mode
Interpulse interval  >100ns
Risetime / falltime ³ 5-7ns
Delay time  <50ns
Jitter  <0.5ns (±250ps)
Load capacitance 5-7pF typically
Protections  From too long pulses (Gate limit), adjusted by the customer in 200ns to 2200ns range³
From overheating
Operation temperature 10 ~ 40°C
Storage temperature  -20 ~ +60 °C
Humidity  90%, non-condensing
Dimension 69x60x32mm
Weight <0.5kg

1. In terms of bipolar output (see also Technical notes sections)

2. Maximal pulse repetition rate depends on pulse amplitude, pulse amplitude and pulse repetition rate cannot achieve their maximums at the same time

3.10-90% level, warranted at load capacitance 11pF and below

4. These and other parameters might be changed upon request

Dimension

Performance

Driver’s performance (i.e. the maximal possible repetition rate) depends on load capacitance, pulse amplitude and the performance of cooling system and limited with internal temperature (we do not recommend to exceed 80-90 °C transistor temperature) and the current consumption (we do not recommend to exceed 5A current consumption).

Pulse width mode - variable Pulse width mode - fixed
   
Triggering - soft Triggering - harsh

 

STHVSW04-OEM Drivers

HVSW-04 is a specialized Pockels cell driver that performance is optimized for pico- and femtosecond lasers. Main applications are pulse picking and regenerative amplifier control.

Maximal output voltage is 4kV; maximal repetition rate is 4MHz at approx. 1.6kV output voltage and 1MHz at approx. 3.2kV output voltage. Target performance is as below:

1.6kV, 4MHz, <300W power consumption

3.2kV, 1MHz, <300W power consumption

Transition times are as fast as 5-7ns in dependence on load capacitance and driver’s configuration. Pulse width is <15ns (fixed), then 100-2000ns (adjustable by the customer).

For operations the driver needs both HV and LV power. HV DC input should be bi-polar. LV power is 24VDC, <2A. Module is water cooled. Different configurations of water inlets available on request.

Interfaces are analogue and RS-485. Configuration software for Windows® 7 is available.

Specifications

LV input

+24V DC; 1.5A max
HV input +HV/2 by one wire; -HV/2 by another wire

Output

Pulses of high voltage and high repetition rate delivered to the capacitive load (e.g. to the Pockels cell)

Output type  Bipolar
Pulse basement ¹  0V, fixed
Pulse amplitude ¹· ² adjustable in 0-4kV range
Maximal repetition rate ² Up to 4MHz 
Minimal repetition rate

Single shot (there is an internal re-striking circuit which makes the operations at such a low repetition rate possible)

Pulse width -Fixed, about 15ns in Fixed pulse width mode
-100ns-2000ns adjustable (customable) in Variable pulse width mode

Interpulse interval 

>100ns
Risetime / falltime ³  5-7ns
Delay time  <50ns
Jitter  <0.5ns (±250ps)
Load capacitance  5-7pF typically
Protections  -From too long pulses (Gate limit), adjusted by the customer in 200ns to 2200ns range³
-From overheating
Operation temperature 10 ~ 40°C
Storage temperature  -20 ~ +60 °C
Humidity  90%, non-condensing
Dimension 69x60x32mm

Weight

<0.5kg

STQBD Series OEM Drivers

STQBD is the series of high repetition rate Pockels cell drivers allowing simple and reliable operation of Q-witched lasers. Devices provide wide range of output direct voltages (up to 6 kV). It allows operation with Pockels cells assembled on different electrooptical crystals from low quarter-wave voltage Lithium Niobate and BBO to DKDP that requires much higher voltage levels for proper operation. STQBD-series Pockels Cell Drivers have modifications both for pull-up and pull down schemes.

STQBD-Series devices provide high repetition rates (up to 100 kHz) that makes them a good solution for electro-optical Q-switched lasers with CW pumping. On the other hand a short rising (falling) time allows operation in short pulsed systems with high peak output power and energy (flashlamp-pumped Nd:YAG lasers).

Another advantage is the ability of operation with extremely high loads (up to 0.5 nF). This feature leads to higher reliability of the device and permits remote operation of Pockels cell in laser head that can be connected to driver using long cables (correct and effective operation has been approved with cables up to 3 meters). This allows the designing of Q-switched laser systems with compact remote laser heads where close placement of Pockels cell and driver is impossible because of volume insufficiency or other causes.

Features:

Specifications

Input:  
Voltage +24VDC
Output:  
Voltage up to 6 kV
Repetition Rate from single pulse to 100 kHz
Load up to 0.5 nF
Rise time (Fall time) 20 ns
Recovery Time 10 us
  (depends on load, @ 100 pF)
Safety:  
Leakage Current not more than 150 uA
Environment:  
Operation Temperature -20…+45 C
Storage Temperature -40…+85 C
Humidity 90%, non-condensing
Size (LxWxH) 110x80x25 mm
Weight 0.1 kg
Options Harsh environment version

Options

Applications

STQBU Series OEM Drivers

Features

Specifications

Input:  
Voltage +24VDC
Output:  
Voltage up to 5 kV
Repetition Rate from single pulse to 100
Load up to 0.5 nF
Rise time (Fall time) 20 ns
Recovery Time 10 us
  (depends on load, @ 100
Safety:  
Leakage Current not more than 150 uA
Environment:  
Operation Temperature -20…+45 C
Storage Temperature -40…+85 C
Humidity 90%, non-condensing
Size (LxWxH) 130x80x20 mm
Weight 0.1 kg
Options Harsh environment version

Options

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