THORLABS GVS001 User manual

HA0193T
GVS001 and GVS002
GVS101 and GVS102
GVS201 and GVS202
Small Beam Diameter
Scanning Galvo Systems
User Guide
Original Instructions

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters
Table of Contents
Chapter 1 Safety Information .............................................................................................1
Chapter 2 Overview .............................................................................................................3
2.2.1 Introduction................................................................................................................................................. 3
2.2.2 The Galvanometer..................................................................................................................................... 3
2.2.3 The Mirror ................................................................................................................................................... 4
2.2.4 Servo Driver Board.................................................................................................................................... 5
Chapter 3 Installation and Initial Setup ............................................................................6
3.2.1 Motor Assembly Dimensions ................................................................................................................... 6
3.2.2 Mirror Dimensions ..................................................................................................................................... 6
3.2.3 Single Axis Mount Dimensions ................................................................................................................ 7
3.2.4 XY Mount Dimensions .............................................................................................................................. 8
3.2.5 Heatsink Dimensions ................................................................................................................................ 8
3.2.6 Servo Driver Board Baseplate Dimensions ........................................................................................... 9
3.3.1 Introduction................................................................................................................................................. 9
3.3.2 Fitting the Heatsinks................................................................................................................................ 10
3.3.3 Typical System Setup ............................................................................................................................. 11
3.4.1 Choosing a Power Supply...................................................................................................................... 12
3.4.2 Using the GPS011 Linear Power Supply ............................................................................................. 12
3.4.3 Electrical Connections ............................................................................................................................ 13
3.4.4 Diagnostic Signal Descriptions .............................................................................................................. 17
3.4.5 Setting the Volts/Degree Scaling Factor .............................................................................................. 17
Chapter 4 Operation ..........................................................................................................18
Chapter 5 Troubleshooting ..............................................................................................20
Chapter 6 Specifications and Associated Parts............................................................24

HA0193T
Chapter 7 Calculating the Power Dissipation................................................................26
7.1.1 Calculating the Required Thermal Conductivity .................................................................................. 26
Chapter 8 Reasons for Image Distortion........................................................................27
Chapter 9 Certifications and Compliance ......................................................................28
Chapter 10 Thorlabs Worldwide Contacts .......................................................................29

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 1: Safety Information
Rev. 25, July 17, 2023 Page 1
Chapter 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.
Warning: Risk of Electrical Shock
Given when there is a risk of electrical shock.
Warning
Given when there is a risk of injury to users.
Caution
Given when there is a possibility of damage to the product.
Note
Clarification of an instruction or additional information.
General Warnings and Cautions
Warning
If this equipment is used in a manner not specified by the manufacturer, the equipment might
malfunction. Excessive moisture may impair operation.
Spillage of fluid, such as sample solutions, should be avoided. If spillage does occur, clean up
immediately using absorbent tissue. Do not allow spilled fluid to enter the internal mechanism.
Although the unit does not emit radiation it does redirect laser radiation emitted from other
devices. Operators must follow all safety precautions provided by the manufacturer of any
associated laser devices.
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.

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 1: Safety Information
Page 2 ETN013002-D02
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 3.4.5 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.
Warning
Please install the metal covers GCE001 to prevent any damage to the motors and PCBs as the
galvo boards contain electrostatic discharge-sensitive components.
EMC Compatibility and ESD Precautions
Caution
Galvos must be shielded from external interference, ground loops, and electrostatic discharge
because they are components and not finished goods. If the covers are not used, a 4kV ESD
can touch the PCB and harm it. Please install covers to shield the boards from ESD.
Note
The customer must adhere to EMC and ESD best practices when integrating any galvo parts
into their systems.
The customer should insulate the galvo and the PCB with shielding and/or ferrite beads if radiofrequency
signals are present in the system since motors can be susceptible to outside radio frequency radiation.
Motors can be sensitive to external radio frequency signals; the customer should protect the galvo and the
PCB with shielding and/or ferrite beads if radio frequency signal are present in the system.
For instance, a Würth Elektronik ferrite 742 711 31 S placed over the motor cable of the large galvo system
can improve immunity between 105 and 115MHz.

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 2: Overview
Rev. 25, July 17, 2023 Page 3
Chapter 2 Overview
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 and two heat sinks. The driver cards feature
a small footprint, fixings for easy mounting to a heatsink and a simple analog command signal interface.
A choice of mirror coating is available as follows:
GVS001 and GVS002: Single- and Dual-Axis Systems with Protected Silver Mirrors
GVS101 and GVS102: Single- and Dual-Axis Systems with Protected Gold Mirrors
GVS201 and GVS202: Single- and Dual-Axis Systems with 400-750 nm Broadband Dielectric Mirrors
Typical applications include laser scanning, laser microscopy, and laser marking.
Figure 1 GVS002 2-Axis Galvo System (Post Adapter and Post Not Included)
System Description
2.2.1 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.
2.2.2 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.

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 2: Overview
Page 4 ETN013002-D02
Figure 2 GVS002 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 an optical position detector, which consists of two pairs of
photodiodes and a light source. As the galvo and mirrors are moved, differing amounts of light are detected
by the photodiodes and the current produced is relative to the galvo actuator position.
2.2.3 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 detailed below:
Table 1 Wavelength Ranges and Damage Threshold
Part Number Coating Wavelength Damage Threshold
GVS00x
Silver
500 nm - 2.0 µm
3 J/cm2at 1064 nm, 10 ns pulse
GVS10x
Gold
800 nm - 20.0 µm
2 J/cm2at 1064 nm, 10 ns pulse
GVS20x
E02
400 nm - 750 nm
0.25 J/cm2 at 532 nm, 10 ns
pulse

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 2: Overview
Rev. 25, July 17, 2023 Page 5
Figure 3 Mirror Assembly Detail
2.2.4 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.
Figure 4 Servo Driver Board Schematic Diagram
Figure 5 Servo Driver Circuit Board

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 3: Installation and Initial Setup
Page 6 ETN013002-D02
Chapter 3 Installation and Initial Setup
Environmental Conditions
Warning
Operation outside the following environmental limits may adversely affect operator safety.
The unit is designed for indoor use only.
To ensure reliable operation, the unit should not be exposed to corrosive agents or excessive moisture, heat,
or dust.
The unit is not designed to be used in explosive environments.
If the unit has been stored at a low temperature or in an environment of high humidity, it must be allowed to
reach ambient conditions before being powered up.
Dimensions
3.2.1 Motor Assembly Dimensions
Figure 6 Motor Dimensions
3.2.2 Mirror Dimensions
Figure 7 Mirror Dimensions

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 3: Installation and Initial Setup
Rev. 25, July 17, 2023 Page 7
3.2.3 Single Axis Mount Dimensions
Figure 8 Single Axis Mounting Bracket Dimensions

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 3: Installation and Initial Setup
Page 8 ETN013002-D02
3.2.4 XY Mount Dimensions
Figure 9 XY Mounting Bracket Dimensions
3.2.5 Heatsink Dimensions
Figure 10 Heatsink Dimensions

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 3: Installation and Initial Setup
Rev. 25, July 17, 2023 Page 9
3.2.6 Servo Driver Board Baseplate Dimensions
Figure 11 Servo Driver Board Baseplate Dimensions
Mechanical Installation
3.3.1 Introduction
Caution
The galvo motor assembly associated driver board and connecting cables 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. Do not extend the cables as this will affect
the system calibration.
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.
The location of the serial number labels is shown below.

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 3: Installation and Initial Setup
Page 10 ETN013002-D02
Figure 12 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
dependent 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.
3.3.2 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.
Secure the heatsink bracket to the heat sink using two M3 x 8 screws and two plain M3 washers (arrowed in
the photo below)
Figure 13 Driver Board Heatsink Screws
Motor/Mirror Mount Heat Sink
Caution
Due to the large torque to weight ratio, thermal management is crucial to the successful
operation of galvo motors. Consequently, the galvo motors must be kept cool (<50 °C).

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 3: Installation and Initial Setup
Rev. 25, July 17, 2023 Page 11
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 combined post adapter and heatsink (GHS003) suitable for both single and dual axis applications.
If using a third party heatsink, please refer Chapter 7 for details on how to calculate the power dissipation in
the motor.
Secure the heastsink to the motor/mirror mount using the two M3 X 5 screws supplied.
Figure 14 XY Mount Heatsink Screws
3.3.3 Typical System Setup
1. Fit a GHS003 post adaptor to the XY mounting block.
2. Fit a lens post into the bottom of the post adapter and clamp it to the breadboard.
3. 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 the screen, also at right angles to the mount.
Typical Example: If the optical scan angle Ø = ±25°
l = 2d x Tan 25° (Note. In this case, the mechanical scan angle is ±12.5°)
Figure 15 Typical Beam Steering System

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 3: Installation and Initial Setup
Page 12 ETN013002-D02
Electrical installation
3.4.1 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 maximum current drawn by
the driver cards will not exceed 1.25 A rms on each rail (the current depends on the application). In addition
to this, for optimum performance the supply should be able to provide peak currents of up to 5A on either
rail.
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. The unit can be damaged if the polarity of the power
rails is reversed
.
3.4.2 Using the GPS011 Linear Power Supply
The unit must be connected only to an earthed (grounded) mains power outlet.
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.
1. Connect the power cord to the socket on the rear panel of the unit. Refer Figure 16.
Figure 16 Rear Panel

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 3: Installation and Initial Setup
Rev. 25, July 17, 2023 Page 13
2. Ensure that the correct voltage range and fuse rating for your region is selected.
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.
3. Plug the power cord into the wall socket.
3.4.3 Electrical Connections
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.
Caution
This section is applicable only to driver card units, with a PCB at rev 11 or later.
PCB revisions can be identified as follows:
Up to and including issue 10.
Steps (1) to 3) are applicable only if using the Thorlabs GPS011 PSU.
1. Ensure the correct voltage range is selected on the PSU. Refer section 3.4.2.

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 3: Installation and Initial Setup
Page 14 ETN013002-D02
2. The circular 3-pin connector on the power output cable and the OUTPUT socket on the PSU are fitted
with alignment keyways to ensure connection in correct orientation. Make connection as referred in
Figure 17.
3. Screw the outer casing of the plug clockwise until the connector is fully fastened.
Figure 17 Connecting the Power Supply to the PSU
Figure 18 Connector Identification
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 (refer section 3.4.1). A bare cable,
crimp connectors (Molex Pt No 2478) and housings for use with general lab PSUs is supplied with each
driver board. The unit can be damaged if the polarity of the power rails is reversed.

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 3: Installation and Initial Setup
Rev. 25, July 17, 2023 Page 15
Figure 19 J10 power 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. Conta
ct tech support for more
details.
5. Connect a motor cable to the connector J9 on each driver board as shown below.
Figure 20 J9 Motor Connector Pin Identification
6. Note the serial numbers and then connect the galvo motors to their associated driver boards.
Figure 21 Galvo Assemble Motor Connector Pin Identification
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
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

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 3: Installation and Initial Setup
Page 16 ETN013002-D02
7. Connect the command input (e.g., function generator) to J7 of each driver board as shown in Figure 22.
J7 accepts Molex pins Pt No 56134-910
Note
The scanner accepts a differential analog command input. If the scaling is 0.8 Volt per degree
mechanical movement (see section 3.4.5), -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 active low, i.e., 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.
Figure 22 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 given below, signal descriptions are added in the next section.
Figure 23 J6 Diagnostics Connector Pin identification
Note
All diagnostic signals from J6 have 1 kΩoutput impedance except Pin 7 (Motor Coil Voltage/2)
which has 5 kΩ.
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
1 2 3 4
8 7 6 5
Pin 1 Command Input +positive
Pin 2 Command Input -negative
Pin 3 DRV OK (Active Low)
Pin 4 External Enable
Pin 5 -12V output (Low Impedance O/P)
Pin 6 +12V Output (Low Impedance O/P)
Pin 7 Ground
Pin 8 Ground
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

Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters Chapter 3: Installation and Initial Setup
Rev. 25, July 17, 2023 Page 17
Example Vendor: Farnell, Vendor P/N: 1120545
Crimps (22-28AWG): Manufacturer: Molex, Mfr. P/N: 56134-9100
Example Vendor: Farnell, Vendor P/N: 1120546
3.4.4 Diagnostic Signal Descriptions
Scanner Position - This signal is proportional 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.
Note
The Scanner Position and Internal Command signals are scaled internally by the driver circuit
and are essentially equivalent to the input signal /2.
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.
3.4.5 Setting the Volts/Degree Scaling Factor
Servo driver cards manufactured after October 2015 have a jumper which is used to set the Volts per Degree
scaling factor. The cards are shipped with the scaling set to 0.8 V/°, where the max scan angle is ±12.5°, and is
compatible with driver cards manufactured before October 2009. To set the scaling factor to 1 V/° and the
maximum scan angle to ±10°, proceed as follows:
1. Identify JP7 as shown in Figure 24 .
2. Set the jumper position for the corresponding scaling factor as shown below.
Note
The 0.5V/° scaling factor is provided to allow the full scan angle to be achieved using small
input signals. In this case, the input voltage should be limited to ±6.25 V max.
Figure 24 Setting the Volts/Degree Scaling Factor
JP7