Electro-Optic Q-Switch Driver

STG Series Pockels Cell Drivers (EO Q-switch Drivers)

1. STG-551 POCKELS CELL DRIVER

The STG-551 driver is designed for use in product development, teaching and research laboratories. 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:

• 4-7ns, 1.5-4.5kV, 1Hz-4.5KHz performance

• 50 ohm isolated trigger

• Front panel controls for high voltage setpoint and power

• DB-9 connector with: voltage monitor, remote setpoint, voltage on/off

• Status LEDs for power, high voltage and trigger

Benefits

• Front panel or remote control

• Short-circuit protected output

• Easy integration of OEM version

• EM shielding enclosure

Applications

Ideal for development of Q-switched lasers for:

• Medical and dermatology

• Imaging

• Engraving

• Metal cutting

• Microfabrication

• Range finding

• Holography

Specifications

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

2. STG-551-OEM POCKELS CELL DRIVER

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

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

Features

• 4-7 ns, 1.5-4.5 kV, 1Hz-4.5 kHz performance (see graph on following page)

• 50 ohm isolated trigger

• Voltage monitor

• Status LEDs for power, high voltage and trigger

• Remote on/off and voltage setpoint

• Bipolar balanced output

• 24 VDC input power

• Laboratory version available

Benefits

• Low power dissipation, less heat

• Remote control ready

• Compact footprint

• Easy integration

Applications

• Medical and dermatological laser systems

• Imaging

• Engraving

• Metal cutting

• Microfabrication

• Range finding

• Holography

Specifications

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

Layout Dimension

3. STG-R200-OEM POCKELS CELL DRIVER

The driver 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

• 4-7 ns rise and fall time

• 0-2.5 kV output voltage

• 0-200 kHz repetition rate

• 250 ns 3 s pulse widths

• Bipolar balanced output

Benefits

• Available as a turn-key system with enclosure

• High performance at a low cost

• Can be air or water cooled

• Compact footprint

Applications

• Metal cutting

• Welding

• Glass and sapphire cutting

• Spectroscopy

Specifications

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

Layout & Dimension

4. STG-QDP50-OEM POCKELS CELL DRIVER

The driver 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

• 1.2-4.0 kV adjustable output voltage

• 0-50 Hz repetition rate

• 400 μs nominal on time (adjustable)

• 160-200 μs delayed pulse (adjustable)

• Fall time (delay pulse) less than 10 ns

• SMA trigger input standard

• Optical trigger input (optional)

Benefits

• Increased Pockels cell life

• High performance at a low cost

• Integrated high voltage power supply

• Compact footprint

Applications

• Medical lasers

• Industrial lasers

• Etching/marking

Specifications

5. STG-HVR POCKELS CELL DRIVER

The driver is designed to switch Pockels cells used for pulse management in high repetition rate ultrafast laser regenerative amplifiers. It 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 driver 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.

We 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

• 0 200 kHz repetition rate pulses

• 1.0 7.5 kV output voltage

• 10 15 ns rise and fall times

• 250 ns 3 μs pulse widths

• Bipolar balanced output

Key Benefits

• Compact footprint

• Reduced heat load

• Easy integration

• Flexible design

Applications

• Metal cutting

• Welding

• Glass cutting

• Sapphire cutting

• Spectroscopy

Specifications

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.

6. STG-HVR-SYSTEM POCKELS CELL DRIVERS

The DRIVER 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. It 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 driver 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 driver 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

• 0-50 kHz repetition rate (air-cooled)

• 0-200 kHz repetition rate (water-cooled)

• 1.0-7.5 kV output voltage

• 10-15 ns rise and fall times

• 250 ns-3 us pulse widths

• Bipolar balanced output

• Standard 483mm (19”) rack mounting

• Dimensions: 432x381x95.25mm (17x15x3.75”)

Key Benefits

• Turn-key driver solution

• Built in digital voltmeter

• Easy integration

• Flexible design

Applications

• Metal cutting

• Welding

• Glass cutting

• Sapphire cutting

• Spectroscopy

Specifications

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

Standard Output Configurations

7. STHVSW-03 OEM Drivers

STHVSW03 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.

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

8. STHVSW04-OEM Drivers

STHVSW-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

STO Series Pockels Cell Drivers (EO Q-switch Drivers)

1. 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:

• Compact OEM design

• Up to 6 kV output voltage

• Long cable operation

• Up to 100 kHz repetition rate

• Up to 0.5 nF load

• Pull-up and pull-down scheme modifications

Specifications

• Part Number Description:

• STQBD-XXYY-ZZ

• STQBD – STQBD series EO Q-switch driver

• XX – maximum output voltage from 20 to 60 (2 - 6kV)

• YY – minimum output voltage from 12 to 20 (1.2 – 2.0kV)

• ZZ – UP: modification for pull-up scheme; DN: modification for pull-down scheme

• Waveform

• We offer five standard solutions:

• STQBD-6024-UP/DN

• STQBD-5020-UP/DN

• STQBD-4016-UP/DN

• STQBD-3012-UP/DN

• STQBD-2008-UP/DN

Options

• Adjustment range of output voltage (see figure) can be selected within the following model series: STQBD-6024 (2.4-6 kV), STQBD-5020 (2-5 kV), STQBD-4016 (1.6-4 kV), STQBD-3012 (1.2-3 kV), STQBD-2008 (0.8- 2 kV).

• STQDB-series Pockels cell drivers have two modifications: working by pull-up scheme or working by pull-down scheme.

• Most of time gate is retained under voltage that is indicated in grey on figure; time of rapid growth/slump (20 ns) is indicated in red; time of relatively slow recovery (~10 us) is indicated in blue. Adjustable voltage level is designated by the arrow.

Applications

• STQBD-Series Pockels Cell Drivers are available in standard and special versions. Standard modification is a relatively simple OEM device designated for operation in laboratory or medical laser systems at normal temperature and humidity conditions. These modules are designed in accordance with IEC60601-1 medical safety standard requirements. Output parameters (direct high voltage) are controlled by use of analog interface.

• Special version is available for laser systems designated for operation in harsh environment. These devices are distinguished due to wide operation temperature range, humidity and vibration steadiness. In this version all parameters are controlled by simple and reliable internal multi-turn trimpots.

2. STQBU Series OEM Drivers

STQBU is a series of multi-functional Pockels cell drivers of hi-end class. In contrast to analogues, they can provide rapid switching of input voltage in two directions: both up and down. STQBU-Series Pockels Cell Driver is extremely flexible solution for driving of the Pockels cell that works upon any user-defined scheme (that may be pull-up, pull-down schemes or any combinations of them).

Modules provide wide range of output direct voltages (up to 5kV). 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.

Moreover, STQBU-Series modules provide high repetition rates (up to 100kHz) 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 of STQBD-series drivers is an ability of handling 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

• Extremely flexible solution

• Pull-up and pull-down schemes

• Up to 5 kV output voltage

• Up to 0.5 nF load

• Compact OEM design

• Long cable operation

• Up to 100 kHz repetition rate

Specifications

• Part Number Description:

• STQBU-XXYY

• STQBU – STQBU series EO Q-switch driver

• XX – maximum output voltage from 20 to 50 (2 - 5kV)

• YY – minimum output voltage from 12 to 20 (1.2 – 2.0kV)

• Output Waveform:

• We offer four standard solutions:

• STQBU-5020

• STQBU-4016

• STQBU-3012

• STQBU-2008

• Other output voltages from 0.8 to 6 kV are available on request

Options

• Adjustment range of output voltage (see figure) can be selected within the following model series: STQBU-6024 (2.4-6 kV), STQBU-5020 (2-5 kV), STQBU-4016 (1.6-4 kV), STQBU-3012 (1.2-3 kV), STQBU-2008 (0.8-2 kV). Time of rapid pulse growth (20 ns) is indicated red on figure time of same rapid slump is indicated blue (20 ns). Adjustable voltage level is designated by the arrow.

• Application

• STQBU-Series Pockels Cell Drivers are available in standard and special versions. Standard modification is a relatively simple OEM device designated for operation in laboratory or medical laser systems at normal temperature and humidity conditions. These modules are designed in accordance with IEC60601-1 medical safety standard requirements. Output parameters (direct high voltage) are controlled by use of analog interface.

• Special version is available for laser systems designated for operation in harsh environment. These devices are distinguished due to wide operation temperature range, humidity and vibration steadiness. In this version all parameters are controlled by simple and reliable internal multi-turn trimpots.

3. STQBU-BT Series EO Q-switch Drivers

STQBU-BT-series consist of five Pockels cell drivers differ with their output voltage range and covering range up to 6.0 kV. High repetition rates and fast transition times are additional benefits.

Modules allow operations in three different modes (pull down scheme (= normally on), push up scheme (= normally off) and external synchronization mode (= repetition of external low voltage signal)) and therefore suit ideally for the laboratory usage.

Features

• Extremely flexible solution

• Push-up and pull-down schemes

• Up to 6 kV output voltage

• Up to 50 kHz (CW) repetition rate

• Pulses width from 1us to DC

• 20 ns rise/fall times

• RS-232 interface

Specifications:

Performance

For STQBU-BT-5020 continuously operated in internal synchronization mode we warrant the performance table as follows:

External synchronization mode shows usually a little higher performance.

In the burst-mode (= short time operations) performance is increasing approximately twice and may achieve 100 kHz value at low operating voltages and load capacitance.

High load capacitance decreases the performance.

Part Number Description: STQBU-BT-XXYY

• STQBU-BT – STQBU-BT series EO Q-switch driver

• XX – maximum output voltage from 20 to 60 (2 - 6kV)

• YY – minimum output voltage from 12 to 20 (1.2 – 2.0kV)

We offer five standard solutions:

• STQBU-BT-6024

• STQBU-BT-5020

• STQBU-BT-4016

• STQBU-BT-3012

• STQBU-BT-2008

Options

Adjustment range of output voltage can be selected within the following model series: STQBU-BT-6024 (2.4-6 kV), STQBU-BT-5020 (2-5 kV), STQBU-BT-4016 (1.6-4 kV), STQBU-BT-3012 (1.2-3 kV), STQBU-BT-2008 (0.8- 2 kV).

4. STQBX-08 Series Arbitrary Waveform Pockels Cell Drivers

APPLICATIONS

• Beam deflection and steering

• Beam intensity control

• Non-optical: PLZ, MEMS etc

FEATURES

• Output voltage – up to 800V

• Fast rise and fall times –<1us

• Repetition rate – up to 1MHz (load and voltage dependent)

• PCB and enclosed versions

STQBX-08 is a dedicated Pockels cell drivers designed for applications where voltage on the Pockels cell should be continuously adjustable. Driver is built on voltage amplifier schematics, maximal output voltage is 800V (other voltages both smaller and higher up to 1600V are available on request), amplification factor is 100:1. Driver is forced air cooled with embedded fan. Driver can be supplied in PCB and enclosed versions.

INTERFACES