THORLABS GVS011 User manual

HA0220T
GVS011 and GVS012
GVS111 and GVS112
GVS211 and GVS212
GVS311 and GVS312
GVS411 and GVS412
Large Beam Diameter
Scanning Galvo Systems
User Guide
Original Instructions

Page 0 20381-D02
Single- and Dual-Axis Scanning Galvo Systems for Large Beam Diameters
Contents
Chaper 1 Overview ..................................................................................................... 1
1.1 Introduction ........................................................................................ 1
1.2 System Description ........................................................................... 2
Chaper 2 Safety .......................................................................................................... 5
2.1 Safety Information ............................................................................. 5
2.2 General Warnings .............................................................................. 5
Chaper 3 Installation & Initial Set Up ........................................................................ 7
3.1 Mechanical Installation ...................................................................... 7
3.2 Electrical Installation ......................................................................... 9
Chaper 4 Operation .................................................................................................. 18
4.1 General Operation ............................................................................ 18
4.2 External Enabling of the driver board ............................................ 18
4.3 Using a DAQ Card ............................................................................ 18
4.4 Recommended Scanning Angles ................................................... 19
Chaper 5 Troubleshooting ....................................................................................... 20
5.1 Common Problems .......................................................................... 20
5.2 Galvanometer Faults ....................................................................... 23
Appendices
Appendix A Specifications ........................................................................................ 24
Appendix B Connecting Legacy Driver Units.......................................................... 27
Appendix C Calculating the Power Dissipation ...................................................... 32
Appendix D Reasons For Image Distortion ............................................................. 33
Appendix E Regulatory............................................................................................... 35
Appendix F Thorlabs Worldwide Contacts............................................................... 37

Rev 19 Oct 2020 Page 1
Chapter 1 Overview
Chapter 1 Overview
1.1 Introduction
The GVS series scanning galvo systems are board level, mirror positioning systems,
designed for integration into OEM or custom laser beam steering applications. The
single axis systems consist of a motor and mirror assembly, a mounting bracket, a
tuned driver card and a heat sink. The dual axis systems comprise two mirror and
motor assemblies, an X-Y mounting bracket, two driver cards with heat sinks and a
post mounting plate. The post mounting plate also serves as a tip/tilt platform adapter
and allows the system to be fitted to a PY003 tilt platform.
The driver cards feature a small footprint, fixings for easy mounting to a heatsink and
a simple analog command signal interface. Typical applications include laser
scanning, laser display, and laser marking.
A choice of mirror coating is available as follows:
GVS011 and GVS012: Single- and Dual-Axis Systems with Protected Silver Mirrors
GVS111 and GVS112: Single- and Dual-Axis Systems with Protected Gold Mirrors
GVS211 and GVS212: Single- and Dual-Axis Systems with 400-750 nm Broadband
Dielectric Mirrors (E02)
GVS311 and GVS312: Single- and Dual-Axis Systems with High Power Dual Band
(532 and 1064 nm) Nd: YAG Mirrors (K13)
GVS411 and GVS412: Single- and Dual-Axis Systems with UV-Enhanced Alumium
Mirrors (F01).
Fig. 1.1 GVS012 2-Axis Galvo System (Post not included)

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Single- and Dual-Axis Scanning Galvo Systems for Large Beam Diameters
1.2 System Description
1.2.1 Introduction
Galvo Scanners are widely used in applications such as laser etching, confocal
microscopy, and laser imaging.
A galvanometer is a precision motor with a limited travel, usually much less than 360
degrees, whose acceleration is directly proportional to the current applied to the motor
coils. When current is applied, the motor shaft rotates through an arc. Motion is
stopped by applying a current of reverse polarity. If the current is removed, the motor
comes to rest under friction.
Typically, the term 'Galvo' refers only to the motor assembly, whereas a 'Galvo
Scanner' would include the motor, together with a mirror, mirror mount and driver
electronics.
A description of each component in the system is contained in the following sections.
1.2.2 The Galvanometer
The galvanometer consists of two main components: a motor that moves the mirror
and a detector that feeds back mirror position information to the system.
Fig. 1.2 GVS012 Dual Axis Galvo/Mirror Assembly
Our galvo motor features a moving magnet, which means that the magnet is part of
the rotor and the coil is part of the stator. This configuration provides faster response
and higher system-resonant frequencies when compared to moving coil
configurations.
Mirror position information is provided by a capacitive position detector.
X-Axis Mirror
Y-Axis Mirror

Rev 19 Oct 2020 Page 3
Chapter 1 Overview
1.2.3 The Mirror
The mirror assembly is attached to the end of the actuator, and deflects the light beam
over the angular range of the motor shaft. Scanning galvo applications demand high
speed and frequencies of the shaft rotation, and so the inertia of the actuator and
mirror assembly can have a profound effect on the performance of the system. High
resonant frequencies and enhanced stiffness in the mirror assembly also add to
system performance by increasing bandwidth and response times.
Wavelength ranges and damage threshold of the different mirror coatings are details
below:
.
Fig. 1.3 GVS012 Motor/Mirror Assembly with GHS003 Heatsink (available separately)
Part No Coating Wavelength Damage Threshold
GVS01x Silver 500 nm - 2.0 µm 3 J/cm2 at 1064 nm, 10 ns pulse
GVS11x Gold 800 nm - 20.0 µm 2 J/cm2 at 1064 nm, 10 ns pulse
GVS21x E02 400 nm - 750 nm 0.25 J/cm2 at 532 nm, 10 ns pulse
GVS31x K13 532 nm and 1064 nm 5 J/cm2 at 1064 nm, 10 ns pulse
GVS41x F01 250nm - 450nm 0.3 J/cm2 at 355 nm, 10 ns, pulse

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Single- and Dual-Axis Scanning Galvo Systems for Large Beam Diameters
1.2.4 Servo Driver Board
The servo circuit interprets the signals from the position detector, then uses positional
error, speed and integral of current terms to output control voltages to drive the
actuator to the demanded position.
The scanner uses a non-integrating, Class 0 servo, which enables higher system
speeds compared to integrating servo systems, and is ideal for use in applications
that require vector positioning (e.g. laser marking) or raster positioning (printing or
scanning laser microscopy). It can also be used in some step and hold applications.
Furthermore, the proportional derivative circuit gives excellent dynamic performance
and includes an additional current term to ensure stability at high accelerations. The
diagram below shows the architecture of the driver in more detail.
Fig. 1.4 Servo Driver Board Schematic Diagram
Fig. 1.5 Servo Driver Circuit Board
Position
Sensing
Circuit
Command
Signal
Amplifier
Difference
Amplifier
Summing
Amplifier
Notch
Filter
Power
Amplifier
Differentiator Jumper
position
speed
error
Current
Sensing
Circuit
Integrator
current

Rev 19 Oct 2020 Page 5
Chapter 2 Safety
Chapter 2 Safety
2.1 Safety Information
For the continuing safety of the operators of this equipment, and the protection of the
equipment itself, the operator should take note of the Warnings, Cautions and Notes
throughout this handbook and, where visible, on the product itself.
The following safety symbols may be used throughout the handbook and on the
equipment itself.
2.2 General Warnings
Warning: Risk of Electrical Shock
Given when there is a risk of injury from electrical shock.
Warning
Given when there is a risk of injury to users.
Caution
Given when there is a risk of damage to the product.
Note
Clarification of an instruction or additional information.
Warning
If this equipment is used in a manner not specified by the manufacturer, the
protection provided by the equipment may be impaired. In particular, excessive
moisture may impair operation.
Spillage of fluid, such as sample solutions, should be avoided. If spillage does
occur, clean up immediately using absorbant tissue. Do not allow spilled fluid to
enter the internal mechanism.

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Single- and Dual-Axis Scanning Galvo Systems for Large Beam Diameters
Caution
When connecting the driver boards and motors use only the cables supplied.
Do not extend the cables. The driver boards and motors are calibrated with
these cables. Using different cables will affect the performance of the system.
Caution
The driver circuit board is shipped calibrated and ready for use. The only
adjustments necessary are setting the Volts/Degree Scaling factor (see Section
3.2.5. and if required, setting the device for external enabling see Section 4.2.
Do not attempt to make any other adjustments or remove/fit any other jumpers
than those explicitly described in the following sections as this could invalidate
the warranty.

Rev 19 Oct 2020 Page 7
Chapter 3 Installation & Initial Set Up
Chapter 3 Installation & Initial Set Up
3.1 Mechanical Installation
3.1.1 Introduction
.
Fig. 3.1 Serial Number Label Location
It is essential that the user mounts heatsinks to the driver board and motor mounts
which are suitable for their intended application. If this is not done the devices will
overheat and permanent damage may occur. The choice of heatsink will primarily be
determined by the power which the devices dissipate, a value which is dependant on
the average speed at which the user moves the scanners. The larger the power the
heatsink must dissipate the larger the heatsink will need to be.
Caution
The Galvo units are set in the clamps at the factory for optimum performance.
In particular, the 2-axis GVS012 is set for optimum orientation between the two
galvo mirrors. Under normal circumstances the position of the units in the clamp
should not be altered. If the need arises for the units to be repositioned, a hex
key is provided to adjust the set screw. It should be noted that this set screw is
M4, irrespective of whether the galvo units are imperial or metric (/M) versions.
The galvo motor assembly and associated driver board are tuned at the factory
before they are shipped and further adjustment is not normally necessary. If the
accuracy of the system is in doubt, e.g due to accidental adjustment of trim pots,
contact Thorlabs for information on the tuning procedure.
During Installation, ensure that the motors are connected to the driver card to
which they were tuned. Both the motor and the driver card should carry the
same serial number. Use only the cables supplied.
The location of the serial number labels is shown below

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Single- and Dual-Axis Scanning Galvo Systems for Large Beam Diameters
3.1.2 Fitting The Heatsinks
Servo Driver Board Heatsink
The servo driver board is supplied complete with a large heatsink, suitable for all applications,
even those involving more vigorous usage and rapidly changing drive waveforms.
1) Secure the heatsink bracket to the heat sink using two M3 x 8 screws and two
plain M3 washers (arrowed in the photo below).
Fig. 3.2 Driver Board Heatsink Screws
Motor/Mirror Mount Heat Sink
For most applications, the mounting bracket will provide adequate heat sinking,
however for more vigorous applications, it may be necessary to fit some heatsinking
in addition to the galvo motor mount. Thorlabs supply a heatsink (GHS003) suitable
for both single and dual axis applications.
If using a third party heatsink, please see Appendix C for details on how to calculate
the power dissipation in the motor.
1) Note the orientation as shown below, then secure the heatsink to the motor/mirror
mount using the two M3 x 5 screws supplied..
Fig. 3.3 XY Mount Heatsink Screws
Caution
Due to the large torque to weight ratio, thermal managment is crucial to the
successful operation of galvo motors. Consequently the galvo motors must be
kept cool (recommended 15 to 35 °C).

Rev 19 Oct 2020 Page 9
Chapter 3 Installation & Initial Set Up
3.1.3 Typical System Set Up
1) Fit a lens post into the bottom of the mounting bracket, then clamp the motor/
mirror assembly to the breadboard.
2) Arrange a beam steering system such that a laser beam shines on to the X axis
mirror, at right angles to the mount and is then reflected onto a screen, also at right
angles to the mount..
Typical example: If the optical scan angle Ø = ±40°
l = 2d x Tan 40° (Note. In this case, the mechanical scan angle is ±20°)
Fig. 3.4 Typical Beam Steering System
3.2 Electrical Installation
3.2.1 Choosing A Power Supply
Thorlabs recommends using the GPS011 linear power supply to power the galvo
controller board(s) as this power supply has been specifically designed for this
purpose. The GPS011 can power up to two driver cards under any drive conditions
and is supplied with all the cables required to connect to the driver cards.
However, customers also have the option of using a third-party power supply or
incorporate the boards into their existing system. In this case care must be taken to
ensure that the power supply voltage and current ratings are within the limits
specified.
The drive electronics require a split rail DC supply in the range ±15V to ±18V. The
cards do not require an accurately regulated supply as the boards themselves have
their own regulators. The maximum current drawn by the driver cards will not exceed
1.2 A rms on each rail. In addition to this, for optimum performance the supply should
be able to provide peak currents of up to 5A on either rail.

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Single- and Dual-Axis Scanning Galvo Systems for Large Beam Diameters
3.2.2 Using the GPS011 Linear Power Supply
The unit must be connected only to an earthed (grounded) mains power outlet.
1) Connect the power cord to the socket on the rear panel of the unit - see Fig. 3.5.
Fig. 3.5 Rear Panel
Caution
Both switching and linear power supplies can be used with the Thorlabs galvo
systems, however it is important to limit the inrush current when the power
supply is turned on, in order to ensure that the power supply reservoir
capacitors on the board are not damaged by the large surge currents that can
occur on power-up. Most power supplies naturally “soft start” when they are
switched on at the mains side and provide inrush current limiting. If, however,
the power supply is turned on at the output (DC) side, it can output its peak
current instantaneously. In this case it is important to limit this peak current to
less than 2 Amps.
Note
The unit is supplied with the input voltage and fuses configured to be compatible in
the region to which it was shipped. No further adjustment should be necessary.
230V
1
0
0
1
1
5
2
3
0
1
0
0
1
1
5
2
3
0
1
0
0
1
1
5
2
3
0
1
0
0
1
1
5
2
3
0

Rev 19 Oct 2020 Page 11
Chapter 3 Installation & Initial Set Up
2) Ensure that the correct voltage range and fuse rating for your region is selected.
3) Plug the power cord into the wall socket.
3.2.3 Electrical Connections
Caution
Selecting the incorrect voltage range or fuse will damage the unit. Ensure that
both switches are set to the correct position for your region and that the fuse
fitted is of the correct rating, as indicated by the screen print on the rear panel.
Caution
During the electrical installation, cables should be routed such that power and
signal cables are separated so that electrical noise pick up is minimized.

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Single- and Dual-Axis Scanning Galvo Systems for Large Beam Diameters
Steps (1) to (3) are applicable only if using the Thorlabs GPS011 PSU.
1) Ensure the correct voltage range is selected on the PSU - see vc
2) The circular 3-pin connector on the power output cable and the OUTPUT socket
on the PSU are fitted with alignment key ways to ensure connection in the correct
Caution
This section is applicable only to driver card units, with a PCB at rev 11 or later.
For details on connecting earlier units, please see Appendix B.
PCB revisions can be identified as follows:
Up to and including issue 10
Issue 11 onwards

Rev 19 Oct 2020 Page 13
Chapter 3 Installation & Initial Set Up
orientation. Check for correct orientation of the alignment key ways, then make
connections as shown in Fig. 3.6.
3) Screw the outer casing of the plug clockwise until the connector is fully fastened.
Fig. 3.6 Connecting the Power Cable to the PSU
Fig. 3.7 Connector Identification
OUTPUT
±15V DC 3.0A/0.1A, 1.4/6.3 msec
OUTPUT
±15V DC 3.0A/0.1A, 1.4/6.3 msec
J9
J6
J10
J7
JP4
JP7

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Single- and Dual-Axis Scanning Galvo Systems for Large Beam Diameters
4) Identify connector J10 on each driver board, and make power connections as
shown below. Thorlabs supply a suitable PSU (GPS011) for powering a single or
dual axis system (see Section 3.2.1.). A bare cable, crimp connectors (Molex Pt
No 2478) and housings for use with general lab PSUs is supplied with each driver
board.
Fig. 3.8 J10 Power Connector Pin Identification
5) Connect a motor cable to the connector J9 on each driver board as shown below.
Fig. 3.9 J9 Motor Connector Pin Identification
Caution
During items (5) and (6) use only the cables supplied. Do not extend the cables.
The driver boards and motors are calibrated with these cables. Using different
cables will affect the performance of the system. Longer cables are available as
a custom part but the units will require re-calibration if these are not specified
at time of order. Contact tech support for more details.
1 +15V
2 Ground
3 -15V
1
2
3
4
5
6
7
8
Pin 1 Position Sensor A Current
Pin 2 Position Sensor Ground
Pin 3 Position Sensor Cable Shield
Pin 4 Drive Cable Shield
Pin 5 Position Sensor B Current
Pin 6 Position Sensor Power
Pin 7 Motor + Coil
Pin 8 Motor -Coil

Rev 19 Oct 2020 Page 15
Chapter 3 Installation & Initial Set Up
6) Note the serial numbers then connect the galvo motors to their associated driver
boards
Fig. 3.10 Galvo Assembly Motor Connector Pin Identification
7) Connect a command input (e.g. function generator) to J7 of each driver board as
shown in Fig. 3.11. J7 accepts Molex pins Pt No 56134-9100.
Note
The scanner accepts a differential analog command input. If the scaling is 0.8 Volt
per degree mechanical movement (see Section 3.3.5.), -10 V to +10 V gives -12.5
to +12.5 degrees mechanical movement. The driver will attempt to set the mirror
position to the command input value.
Pin 3 (DRV_OK) is an open collector output that is low when the board is operating
normally and floating if a fault occurs. To use Pin 3 as a fault indicator, connect a
pull-up resistor to give a high signal when the fault occurs. DRV_OK limits are 30 mA
30 V.
Do not connect a relay to this output.
1
3
5
7
9
2
4
6
8
10
Pin 1 Motor + Coil (power shield floating)
Pin 2 Motor -Coil (power shield floating)
Pin 3 Not Used
Pin 4 Not Used
Pin 5 Position Sensor B Current
Pin 6 Position Sensor Ground
Pin 7 Position Sensor A Current
Pin 8 Position Sensor Power
(Automated Gain Control)
Pin 9 Position Sensor Cable Shield
Pin 10 Not Used

Page 16 20381-D02
Single- and Dual-Axis Scanning Galvo Systems for Large Beam Diameters
.
Fig. 3.11 J7 Command Input Connector Pin Identification
8) Using a suitable cable, connect the Diagnostic Terminal J6 to the diagnostic
device (e.g. oscilloscope) in your application. Pin identification is givem below,
signal descriptions are detailed in the next section.
Fig. 3.12 J6 Diagnostics Connector Pin Identification
J6 Diagnostics and J7 Command Input Mating Connector Details
Mating Connector body: Manufacturer: Molex, Mfr. P/N: 513530800
Example Vendor: Farnell, Vendor P/N: 1120387
Crimps (22-26AWG): Manufacturer: Molex, Mfr. P/N: 56134-8100
Example Vendor: Farnell, Vendor P/N: 1120545
Crimps (22-28AWG): Manufacturer: Molex, Mfr. P/N: 56134-9100
Example Vendor: Farnell, Vendor P/N: 1120546
Note
All diagnostic signals from J6 have 1 KW output impedance except Pin 7 (Motor Coil
Voltage/2) which has 5 KW.
1 2 3 4
8 7 6 5
Function
Generator
J7
1
2
7/8
+
-
Function
Generator
J7
1
2
7/8
+
-
Standard O/P
Differential O/P
Earth
Pin 1 Command Input +ve
Pin 2 Command Input -ve
Pin 3 DRV OK
Pin 4 External Enable
Pin 5 -12V Output (low impedence O/P)
Pin 6 +12V Output (low impedence O/P)
Pin 7 Ground
Pin 8 Ground
1
Pin 1 Scanner Position
Pin 2 Internal Command Signal
Pin 3 Positioning Error x 5
Pin 4 Motor Drive Current
Pin 5 Not Connected
Pin 6 Test Input (NC)
Pin 7 Motor + Coil Voltage / 2
Pin 8 Ground
2
3
4
8
7
6
5

Rev 19 Oct 2020 Page 17
Chapter 3 Installation & Initial Set Up
3.2.4 Diagnostic Signal Descriptions
Scanner Position - This signal is proprotional to the position of the scanner mirror, with
a scaling of 0.5 Volts per degree of mechanical movement.
Internal Command Signal - The command signal following amplification by the input
stage. The scaling is 0.5 Volt per degree of mechanical movement.
Positioning Error x 5 - This signal is proportional to the difference between the
demanded and the actual positions - (Position - Command) x 5 (i.e. (Pin 1 - pin 2) x 5).
Motor Drive Current - The drive current of the motor (2V per A), i.e. if drive signal is
2V, the drive current is 1 A.
Motor + Coil Voltage /2 - This pin outputs the drive voltage to the “+” side of the motor coil.
It is scaled down by a factor of 2. The drive voltage determines the current, which then
determines the acceleration. It is not required if the user only wants to monitor position.
3.2.5 Setting the Volts/Degree Scaling Factor
The servo driver cards have a jumper which is used to set the Volts per Degree
scaling factor. The cards are shipped with the scaling set to 0.5 V/°, where the max
mechanical scan angle is nominally ±20° for the full ±10 V input.
To set the scaling factor to 0.8 V/° or 1.0 V/°, proceed as follows:
1) Identify JP7 as shown in Fig. 3.13.
2) Set the jumper position for the corresponding scaling factor as shown below.
Fig. 3.13 Setting the Volts/Degree Scaling Factor
Note
The Scanner Position and Internal Command signals are scaled internally by the
driver circuit and are essentially equivalent to the input signal /2.
1V/° 0.8V/° 0.5V/°
JP7

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Single- and Dual-Axis Scanning Galvo Systems for Large Beam Diameters
Chapter 4 Operation
4.1 General Operation
1) Connect the system as described in Section 3.2.
2) Apply power to the driver boards.
3) Input a command signal to each driver board to obtain the desired behaviour.
4.2 External Enabling of the driver board
1) The drive electronics can be configured for external enabling by
placing a jumper across pins 2 and 3 of JP4.
2) Once this has been done the user can enable or disable the drive electronics by
applying a 5V CMOS signal to J7 pin 4.
Fig. 4.1 J7 Command Input Connector Pin Identification
If a logic high or no signal is applied the drive electronics will be enabled. If a logic low
signal is applied then the driver will be disabled.
4.3 Using a DAQ Card
Typically, users will deploy a DAQ card with DAC analogue outputs in order to drive
the servo drivers supplied with the galvos. The minimum recommended
specifications for the DAC outputs are:-
Dual bipolar -10V to 10V DAC analogue output channels (differential).
DAC clocking frequency higher than 20kS/s (Kilo Samples/Second), higher sampling
frequencies like 100 kS/s are recommended (inputs have a 7 kHz low pass filter).
16 Bit DAC resolution and low out impedance (<= 50 
Note
After powering the boards, there may be a delay of up to 10 seconds before the
motors start to follow the command signal.
1 2 3
1 2 3 4
8 7 6 5
Pin 1 Command Input +ve
Pin 2 Command Input -ve
Pin 3 No Connect
Pin 4 External Enable
Pin 5 -12V Output
Pin 6 +12V Output
Pin 7 Ground
Pin 8 Ground