THORLABS GVS001 User manual

HA0193T
GVS001 and GVS002
GVS101 and GVS102
GVS201 and GVS202
GVS301 and GVS302
Scanning Galvo Systems
User Guide
Original Instructions

Page 0 18728-D01
Single- and Dual-Axis Scanning Galvo Systems for Small 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 ........................................................................ 6
3.1 Dimensions ......................................................................................... 6
3.2 Mechanical Installation .................................................................... 10
3.3 Electrical Installation ....................................................................... 12
Chaper 4 Operation .................................................................................................. 19
4.1 General Operation ............................................................................ 19
4.2 External Enabling of the driver board ............................................ 19
4.3 Using a DAQ Card ............................................................................ 19
4.4 Recommended Scanning Angles ................................................... 20
Chaper 5 Troubleshooting ....................................................................................... 21
5.1 Common Problems .......................................................................... 21
5.2 Galvanometer Faults ....................................................................... 24
Appendices
Appendix A Specifications and Associated Products .............................. 25
1.1 Specifications ................................................................................... 25
1.2 Associated Products ....................................................................... 26
Appendix B Calculating the Power Dissipation ........................................ 27
Appendix C Reasons For Image Distortion ............................................... 28
Appendix D Regulatory................................................................................. 30

Rev 22 Feb 2019 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 consists of a motor and mirror assembly, a mounting bracket, a
tuned driver card and a heat sink. The dual axis systems comprises 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
GVS301 and GVS302: Single- and Dual-Axis Systems with High Power Dual Band
(532 and 1064 nm) Nd: YAG Mirrors
Typical applications include laser scanning, laser microscopy, and laser marking.
Fig. 1.1 GVS002 2-Axis Galvo System (Post Adapter and post not included)

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Single- and Dual-Axis Scanning Galvo Systems for Small 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 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.
X-Axis Mirror
Y-Axis Mirror

Rev 22 Feb 2019 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 Mirror Assembly Detail
Part No Coating Wavelength Damage Threshold
GVS00x Silver 500 nm - 2.0 µm 3 J/cm2 at 1064 nm, 10 ns pulse
GVS10x Gold 800 nm - 20.0 µm 2 J/cm2 at 1064 nm, 10 ns pulse
GVS20x E02 400 nm - 750 nm 0.25 J/cm2 at 532 nm, 10 ns pulse
GVS30x K13 532 nm and 1064 nm 5 J/cm2 at 1064 nm, 10 ns pulse

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Single- and Dual-Axis Scanning Galvo Systems for Small 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 22 Feb 2019 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.
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.

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Single- and Dual-Axis Scanning Galvo Systems for Small Beam Diameters
Chapter 3 Installation & Initial Set Up
3.1 Dimensions
3.1.1 Motor Assembly Dimensions
Fig. 3.1 Motor Dimensions
3.1.2 Mirror Dimensions
Fig. 3.2 Mirror Dimensions
0.09 (2.3)
0.06 (1.5)
1.22
(31.0)
Ø 0.9
(23.2)
1.49 (37.8)
0.87 (22.0)
Ø 0.5 (12.6)
Ø 0.1 (2.5)
all dimensions in inches (mm
)
0.57 (14.5)
0.34
(8.5)
0.04
(1.0)
0.04
(1.0)
0.39
(10.0)
0.32 (8.0)
X-Axis Mirror
Y-Axis Mirror
all dimensions in inches (mm
)

Rev 22 Feb 2019 Page 7
Chapter 3 Installation & Initial Set Up
3.1.3 Single Axis Mount Dimensions
Fig. 3.3 Single Axis Mounting Bracket Dimensions
0.55
(14.0)
0.55
(14.0)
all dimensions in inches (mm)
1.5 (38.0)
0.75 (19.0)
0.53
(13.5)
0.53
(13.5)
0.35 (9.0)
0.35 (9.0)
0.33 (8.5)
0.33 (8.5)
2 x Ø2.5 8.0
M3 x 0.5 -6H 6.0
2 x Ø 2.5 8.0
M3 x 0.5 -6H 6.0
M3 x 0.5 -6H
0.12
(3.0)
Ø 0.52 (13.2)
0.43 (11.0)
0.43
(11.0)
R 0.04 (1.0)
0.79
(20.0)
0.65
(16.5)
1.38
(35.0)
0.03 (0.75)
0.06 (1.5)
Qty 5 SLOTS 0.08 (2.0) Typ
0.08 (2.0) Typ
0.59 (15.0)
0.98
(25.0)
0.39
(10.0)
0.17
(4.3)
Ø 6.0 3.0
Ø 3.5 to SLOT

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Single- and Dual-Axis Scanning Galvo Systems for Small Beam Diameters
3.1.4 XY Mount Dimensions
Fig. 3.4 XY Mounting Bracket Dimensions
0.67 (17.0)
1.5 (38.0)
0.6 (16.0)
0.75
(19.0)
1.1
(28.0)
0.98
(25.0) 0.39
(10.0)
0.75
(19.0)
0.24
(6.0)
0.87 (22.0)
0.55 (14.0) 1.34 (34.0)
0.55
(14.0)
0.2
(5.0)
0.06
(1.5)
0.06
(1.5)
0.39
(10.00)
0.04
(1.0)
0.07
(1.8)
0.2
(5.0)
0.2
(5.0) 0.2 (5.0)
M3 x 6 Qty 3
M3 x 6 Qty 3
Ø 0.52 (13.2)
Ø 0.52 (13.2)
Ø 0.14 (3.5)
CSK 0.24 (6.0) Qty 2
0.39
(10.00)
1.16
(29.5)
1.58
(40.0)
0.02 (0.5)
0.02
(0.5)
0.17
(4.3)
0.34
(8.5)
all dimensions in inches (mm)

Rev 22 Feb 2019 Page 9
Chapter 3 Installation & Initial Set Up
3.1.5 Heatsink Dimensions
Fig. 3.5 Heatsink Dimensions
3.1.6 Servo Driver Board Baseplate Dimensions
Fig. 3.6 Servo Driver Board Baseplate Dimensions
100.0 (3.94)
Drill & Tap M3 Thru
52.0 (2.05)
19.0 (0.75)
GHS002
97.0
(3.82)
11.20
(0.44)
10.40
(0.41)
3.0 (0.12)
24.0 (0.94)
25.0 (0.98)
85.1
44.2 (1.74)
7.2
(0.28)
1.6
(0.06)
24.2 (0.95)
M3 (3 Positions)
3.5 (0.14) DIA
25.5
(1.0)
45.88
(1.81)
66.0
(2.6)
74.0
(2.9)
5.0 (0.2)
9.07
(0.36)
45.0 (1.77)
33.0 (1.3)
15.0 (0.59) 3.0
(0.12)
4.8 (0.19)
3.0
(0.12)
6.0 Typ
(2.36)
54.0 (2.13)
Slot
52.5 (2.07)
74.8 (2.95)
3.3 (0.13)
6.5 (0.26)
All dimensions in mm (inches)
3.5 (0.14) DIA and
CSK to Suit
M3 Screw on Underside
(4 Positions)

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Single- and Dual-Axis Scanning Galvo Systems for Small Beam Diameters
3.2 Mechanical Installation
3.2.1 Introduction
.
Fig. 3.7 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.
3.2.2 Fitting The Heatsinks
Caution
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.
The location of the serial number labels is shown below.

Rev 22 Feb 2019 Page 11
Chapter 3 Installation & Initial Set Up
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. 3.8 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 combined post adapter and
heatsink (GHS003) suitable for both single and dual axis applications.
If using a third party heatsink, please see Appendix B for details on how to calculate
the power dissipation in the motor.
1)
Secure the heatsink to the motor/mirror mount using the two M3 x 5 screws supplied .
Fig. 3.9 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 (<50 °C).

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Single- and Dual-Axis Scanning Galvo Systems for Small Beam Diameters
3.2.3 Typical System Set Up
1) Fit a GHS003 post adapter 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 a 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°)
Fig. 3.10 Typical Beam Steering System
3.3 Electrical Installation
3.3.1 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.

Rev 22 Feb 2019 Page 13
Chapter 3 Installation & Initial Set Up
3.3.2 Using the GPS011 Linear Power Supply
The unit is supplied with a variety of mains power cords.
1) Select the power cord appropriate for your territory.
2) Connect the power cord to the socket on the rear panel of the unit - see Fig. 3.11.
3) Select the correct voltage range for your region.
4) Plug the power cord into the wall socket.
Fig. 3.11 Power Supply Unit 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.
Caution
Selecting the incorrect voltage range will damage the unit.

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Single- and Dual-Axis Scanning Galvo Systems for Small Beam Diameters
3.3.3 Electrical Connections
Fig. 3.12 Connector Identification
1) 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 3.3.1.). A bare cable, crimp connectors (Molex Pt
No 2478) and housings for use with general lab PSUs is supplied with each driver
board.
Fig. 3.13 J10 Power Connector Pin Identification
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.
J9
J6
J10
J7
JP4
1 2 3
JP7
1 +15V
2 Ground
3 -15V

Rev 22 Feb 2019 Page 15
Chapter 3 Installation & Initial Set Up
2) Connect the motor cable to the connector J9 on each driver board as shown
below.
Fig. 3.14 J9 Motor Connector Pin Identification.
3) Note the serial numbers of the galvo motors and driver boards, then connect the
galvo motors to their associated driver boards. If using a custom cable, the pin
outs for the connectorson the Driver PCB and the Motor connector are detailed in
Fig. 3.14 and Fig. 3.15 respectively.
Fig. 3.15 Galvo Assembly Motor Connector Pin Identification
Caution
During item (2) and (3) 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
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
5
4
3
2
1
6
7
8
9
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

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Single- and Dual-Axis Scanning Galvo Systems for Small Beam Diameters
4) Connect a command input (e.g. function generator) to J7 of each driver board as
shown in Fig. 3.16. J7 accepts Molex pins Pt No 56134-9100.
.
Fig. 3.16 J7 Command Input Connector Pin Identification
5) 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. 3.17 J6 Diagnostics Connector Pin Identification
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.
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
Ground
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 22 Feb 2019 Page 17
Chapter 3 Installation & Initial Set Up
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

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Single- and Dual-Axis Scanning Galvo Systems for Small Beam Diameters
3.3.4 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.
3.3.5 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 Fig. 3.18.
2) Set the jumper position for the corresponding scaling factor as shown below.
Fig. 3.18 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.
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
1V/° 0.8V/° 0.5V/°
JP7