Large Beam Diameter Single-Axis Scanning Galvo Systems


  • For Beam Diameters up to 10 mm
  • Choice of Dielectric or Metallic Mirror Coating
  • Easy Integration into OEM Systems
  • Analog Control Electronics

GVS011

Galvo Scanning System
with Silver-Coated Mirror

Single-Axis Motor/Mirror Assembly
(Shown with Gold-Coated Mirror)

GHS003

Heatsink

Related Items


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Key Specificationsa,b
Beam Diameter 10 mm (Max)
Repeatability 15 μrad
Linearity (50% Full Travel) 99.9%
Max Mechanical Scan Angle ±20.0° (w/ 0.5 V/deg Scaling)
Bandwidth (Full Travel) 25 Hz Square Wave
35 Hz Sine Wave
Bandwidth (50% Full Travel) 65 Hz Square Wave
130 Hz Sine Wave
Small Angle (±0.2°) Bandwidth 1 kHz
Small Angle Step Responsec 400 µs
Analog Position Signal Input Range ±10 V
Mechanical Position Signal Input Scale Factord 1.0 V, 0.8 V, or 0.5 V per degree
Position Sensor Output 40 to 80 µA
  • For complete specifications, please see the Specs tab.
  • All specifications are valid after 60 seconds upon power on.
  • The settling time for the mirror to stop moving once the drive signal is removed.
  • See the diagram titled "JP7 Volts/Degree Scaling Factor Control" on the Pin Diagrams tab for more details.

Features

  • Moving Magnet Motor Design for Fast Response (400 µs for ±0.2°)
  • High-Precision (15 µrad) Capacitive Mirror Position Detection
  • Analog Control Electronics with Current Damping and Error Limiter
  • Choice of Mirror Coatings (See Table Below)
  • Custom Coatings Available upon Request (Contact Tech Support for More Details)

These high-speed Scanning Galvanometer Mirror Positioning Systems are designed for integration into OEM or custom laser beam steering applications with a beam diameter of <10 mm. Each system includes a single-axis galvo motor and mirror assembly, associated driver card, and driver card heatsink. Also provided is a base plate, which allows the assembly to be mounted on our TR series posts and our range of tilt platforms. A low-noise, linear power supply (Item # prefix GPS011) and a cover for the driver card (GCE001) are available separately (see below for details). Upon initial setup of the system, a function generator or DAQ card will be needed for operating the servo drivers; see Chapters 3 and 4 in the manual for additional information.

The mirrors are offered with one of five coatings, as shown in the table below. Custom coatings are available upon request. Please contact Tech Support for more details.

Item # GVS411(/M) GVS211(/M) GVS011(/M) GVS311(/M) GVS111(/M)
Coating UV-Enhanced Aluminum Broadband Dielectric (-E02) Protected Silver Nd:YAG Fundamental
and 2nd Harmonic (-K13)
Protected Gold
Wavelength Rangea
(Ravg > 95%)
250 - 450 nm 400 - 750 nm 500 nm - 2.0 µm 532 nm and 1064 nm 800 nm - 20 µm
Damage Thresholds 0.3 J/cm2 at 355 nm
(10 ns, 10 Hz, Ø0.381 mm)
0.25 J/cm2 at 532 nm
(10 ns, 10 Hz, Ø0.803 mm)
3 J/cm2 at 1064 nm
(10 ns, 10 Hz, Ø1.000 mm)
8 J/cm2 at 532 nm
(10 ns, 10 Hz, Ø0.491 mm)
5 J/cm2 at 1064 nm
(10 ns, 10 Hz, Ø1.010 mm)
2 J/cm2 at 1064 nm
(10 ns, 10 Hz, Ø1.000 mm)
  • See the Graphs tab for reflectance curves.

GVS001 Schematic

Galvo Motor/Mirror Assembly
The galvo consists of a galvanometer-based scanning motor with an optical mirror mounted on the shaft and a detector that provides positional feedback to the control board. The moving magnet design for the GVS series of galvanometer motors was chosen over a stationary magnet and rotating coil design in order to provide the fastest response times and the highest system resonant frequency. The position of the mirror is encoded using a capacitive sensing system located inside of the motor housing.

Due to the large angular acceleration of the rotation shaft, the size, shape, and inertia of the mirrors become significant factors in the design of high performance galvo systems. Furthermore, the mirror must remain rigid (flat) even when subjected to large accelerations. All these factors have been precisely balanced in our galvo systems in order to match the characteristics of the galvo motor and maximize performance of the system.

The galvo mirrors are secured to the motor/mirror assembly by a flexure clamp. The positions of the mirror holders are set at the factory and should not be changed by the user.


GVS012 System
Click to Enlarge

GVS011 Silver-Coated Galvo Mirror Assembly and Driver Board

Scanning Galvo Mirror Assembly and Driver Board
All Thorlabs scanning galvo mirror systems feature a mounted single- or dual-axis mirror/motor assembly and driver card(s). Shown to the right is the silver-coated 10 mm 1D galvo mirror assembly with driver card. The mirror assembly features multiple mounting holes and a rotatable collar mount for the mirror/motor. A flying lead allows connection to the driver board. Please see below for additional mounting options and accessories.

Servo Driver Board
The Proportional Derivative (PD) servo driver circuit interprets the signals from the optical position detecting system inside the motor and then produces the drive voltage required to rotate the mirror to the desired position. The scanner uses a non-integrating, Class 0 servo that is ideal for use in applications that require vector positioning (e.g., laser marking), raster positioning (printing or scanning laser microscopy), and some step-and-hold applications. Furthermore, the proportional derivative controller gives excellent dynamic performance. The circuit includes an additional current term to ensure stability at high accelerations. The same driver board is used in all of our galvo systems.


System Operation
The servo driver must be connected to a DC power supply, the galvo motor, and an input voltage source (the monitoring connection is optional). For continuous scanning applications, a function generator with a square or sine wave output is sufficient for scanning the galvo mirror over its entire range. For more complex scanning patterns, a programmable voltage source such as a DAQ card can be used. Please note that these systems do not include a function generator or a DAQ card. The ratio between the input voltage and mirror position is switchable between 0.5 V/°, 0.8 V/°, and 1 V/°. For the GVSx11 systems, the ±10 V input produces the full angular range of ±20° with a scaling factor of 0.5. The control circuit also provides monitoring outputs that allow the user to track the position of the mirror. In addition, voltages proportional to the drive current being supplied to the motor and the difference between the command position and the actual position of the mirror are supplied by the control circuit.

Closed-Loop Mirror Positioning
The angular orientation (position) of the mirror is measured using a capacitive sensing system, which is integrated into the interior of the galvanometer housing, and allows for the closed-loop operation of the galvo mirror system.

The GVSx11 systems can be driven to scan their full ±20° range at a frequency of 65 Hz when using a square wave control input voltage and 130 Hz when using a sine wave. For a ±0.2° small angle, the step response is 400 µs. The maximum scan frequency is 1 kHz and the angular resolution is 0.0008° (15 μrad, with GPS011-xx Linear Power Supply).

Galvanometer System Specificationsa

Item # GVS411(/M) GVS211(/M) GVS011(/M) GVS311(/M) GVS111(/M)
Mirror
Maximum Beam Diameter 10 mm
Substrate Quartz
Coating UV-Enhanced Aluminum Broadband Dielectric (-E02) Protected Silver Nd:YAG Fundamental
and 2nd Harmonic (-K13)
Protected Gold
Wavelength Range 250 - 450 nm 400 - 750 nm 500 nm - 2.0 µm 532 nm and 1064 nm 800 nm - 20 µm
Damage Threshold 0.3 J/cm2 at 355 nm
(10 ns, 10 Hz, Ø0.381 mm)
0.25 J/cm2 at 532 nm
(10 ns, 10 Hz, Ø0.803 mm)
3 J/cm2 at 1064 nm
(10 ns, 10 Hz, Ø1.000 mm)
8 J/cm2 at 532 nm
(10 ns, 10 Hz, Ø0.491 mm)
5 J/cm2 at 1064 nm
(10 ns, 10 Hz, Ø1.010 mm)
2 J/cm2 at 1064 nm
(10 ns, 10 Hz, Ø1.000 mm)
Parallelism <3 arcmin
Surface Quality 40-20 Scratch-Dig
Front Surface Flatness (@633 nm) λ
Clear Aperture >90% of Dimension
Motor and Position Sensor
Linearity (50% Full Travel) 99.9%
Scale Driftb <200 ppm/°C (Max)
Zero Driftb <20 μrad/°C (Max)
Repeatability 15 μrad
Resolution (Mechanical) With GPS011 Linear Power Supply: 0.0008° (15 µrad)
With Standard Switching Mode Power Supply: 0.004° (70 µrad)
Average Current 1 A
Peak Current 10 A
Maximum Scan Angle
(Mechanical Angle)
±20.0° (Input Scale Factor 0.5 V per degree)
Motor Weight
(including Cables, excluding Brackets)
94 g
Operating Temperature Range 15 to 35 °C
Position Sensor
Output Range
40 to 80 µA
Drive Electronics
Full Travel Bandwidthc 25 Hz Square Wave, 35 Hz Sine Wave
Bandwidth (50% Full Travel) 65 Hz Square Wave, 130 Hz Sine Wave
Small Angle (±0.2°) Bandwidth 1 kHz
Small Angle Step Responsed 400 µs
Power Supply ±15 to ±18 VDC
(1.25 A rms, 10 A Peak Max)
Analog Signal Input Resistance 20 kΩ ± 1% (Differential Input)
Position Signal Output Resistance 1 kΩ ± 1%
Analog Position Signal Input Range ±10 V
Mechanical Position Signal Input Scale Factore Switchable: 1.0 V, 0.8 V or 0.5 V per degree
Mechanical Position Signal Output Scale Factor 0.5 V per degree
Operating Temperature Range 15 to 35 °C
Servo Board Size (W x D x H) 85 mm x 74 mm x 44 mm (3.35" x 2.9" x 1.73")
  • All specifications are valid after 60 seconds upon power on.
  • Measured after leaving the unit powered up for at least 8 hours (max drift is <0.8 mrad in 8 hrs upon power on).
  • The unit can operate beyond these limits with reduced performance until protections trigger (250 Hz <10 sec). For a safe operation, stay below 50 Hz 20 Vpp sine wave.
  • The settling time for the mirror to stop moving once the drive signal is removed.
  • See the diagram titled "JP7 Volts/Degree Scaling Factor Control" on the Pin Diagrams tab for more details.

Maximum Recommended Scan Angles

Input Beam Diameter Max Optical Scan Angle (Beam Angle) Mechanical Scan Angle (Motor Angle)
10 mm +40° / -16° +20° / -8°
8 mm +40° / -32° +20° / -16°
7 mm and Less ±40° ±20°

Power Supply Specifications

Item # GPS011-US GPS011-EC GPS011-JP
Input Voltage 115 VAC, 60 Hz 230 VAC, 50 Hz 100 VAC, 50/60 Hz
Output Voltage ±15 VDC, 3.0 A / 0.1 A, 1.4/6.3 ms
Fuses T2.0 A Anti-Surge Ceramic T1.0 A Anti-Surge Ceramic T2.5 A Anti-Surge Ceramic
Dimensions 179 mm x 274 mm (Max) x 122 mm
(7.05" x 10.79" (Max) x 4.8")
Weight 4.73 kg (10.4 lbs)

The curves below show the reflection data for the coated mirrors supplied with the GVS series galvo systems. The shaded regions denote the ranges over which we recommend using the respective coating. Please note that the reflectance outside of these bands is not as rigorously monitored in quality control, and can vary from lot to lot, especially in out-of-band regions where the reflectance is fluctuating or sloped.

Protected Silver at 45 Degree Incident Angle
Click to Enlarge

Excel Spreadsheet with Raw Data for Protected Silver
Protected Gold at 45 Degree Incident Angle
Click to Enlarge

Excel Spreadsheet with Raw Data for Protected Gold

 

-E02 Coating Range, 45° AOI
Click to Enlarge

Excel Spreadsheet with Raw Data for E02 Coating
UV-Enhanced Aluminum at 45 Degree Incident Angle
Click to Enlarge

Excel Spreadsheet with Raw Data for UV-Enhanced Aluminum

 

Dual Band Nd:YAG Coating at 45 Degree Incident Angle
Click to Enlarge

Excel Spreadsheet with Raw Data for K13 Coating
Dual Band Nd:YAG Coating at 45 Degree Incident Angle
Click to Enlarge

Excel Spreadsheet with Raw Data for K13 Coating

This tab contains information regarding the power connector, diagnostics connector, motor connectors, command input connector, and degree scaling factor control on the GVS series driver boards.

GVS Series Driver Connections

GVS Driver

 

 

J10 Power Connector

GVS J10
Pin Designation
1 + 15 V
2 Ground
3 - 15 V

J6 Diagnostics Connector

GVS J6
Pin Designation
1 Scanner Position
2 Internal Command Signal
3 Positioning Error x 5
4 Motor Drive Current
5 Not Connected
6 Test Input (NC)
7 Motor + Coil Voltage / 2
8 Ground

 

J9 Motor Connector

J9
Pin Designation
1 Position Sensor A Current
2 Position Sensor Ground
3 Position Sensor Cable Shield
4 Drive Cable Shield
5 Position Sensor B Current
6 Position Sensor Power
7 Motor + Coil
8 Motor - Coil

Galvo Assembly Motor Connector
GVS001/GVS002 Only

Motor Connector
Pin Designation
1 Motor + Coil
2 Not Used
3 Motor - Coil
4 Position Sensor Cable Shield
5 Not Used
6 Position Sensor Power
7 Not Used
8 Position Sensor A Current
9 Position Sensor B Current
10 Position Sensor Ground

J7 Command Input Connector

J7
O/P
Pin Designation
1 Command Input +ve
2 Command Input -ve
3 DRV OK
4 External Enable
5 -12 V Output (low impedance O/P)
6 +12 V Output (low impedance O/P)
7 Ground
8 Ground

 

JP7 Volts/Degree Scaling Factor Control

JP7

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 maximum mechanical scan angle is nominally ±20° for the full ±10 V input. To change the scaling factor, set the jumper on JP7 as shown above.

External Enabling of the Driver Board

The drive electronics can be configured for external enabling by placing a jumper across pins 2 and 3 of JP4.

JP4
JP4

Once this has been done, the user can enable or disable the drive electronics by applying a 5 V CMOS signal to J7 pin 4.

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.

Pin Designation
1 Command Input +ve
2 Command Input -ve
3 No Connect
4 External Enable
5 -12 V Output
6 +12 V Output
7 Ground
8 Ground

J7
J7

Damage Threshold Specifications
Item # Damage Threshold
GVS012(/M) 3 J/cm2 at 1064 nm
(10 ns, 10 Hz, Ø1.000 mm)
GVS112(/M) 2 J/cm2 at 1064 nm
(10 ns, 10 Hz, Ø1.000 mm)
GVS212(/M) 0.25 J/cm2 at 532 nm
(10 ns, 10 Hz, Ø0.803 mm)
GVS312(/M) 8 J/cm2 at 532 nm
(10 ns, 10 Hz, Ø0.491 mm)
5 J/cm2 at 1064 nm
(10 ns, 10 Hz, Ø1.010 mm)
GVS412(/M) 0.3 J/cm2 at 355 nm
(10 ns, 10 Hz, Ø0.381 mm)

Damage Threshold Data for Thorlabs' Large Beam Diameter Scanning Galvo Systems

The specifications to the right are measured data for Thorlabs' large beam diameter scanning galvo systems. Damage threshold specifications are constant for all larger diameter scanning galvo system, regardless of the drivers or measurement system of galvo system.

 

Laser Induced Damage Threshold Tutorial

The following is a general overview of how laser induced damage thresholds are measured and how the values may be utilized in determining the appropriateness of an optic for a given application. When choosing optics, it is important to understand the Laser Induced Damage Threshold (LIDT) of the optics being used. The LIDT for an optic greatly depends on the type of laser you are using. Continuous wave (CW) lasers typically cause damage from thermal effects (absorption either in the coating or in the substrate). Pulsed lasers, on the other hand, often strip electrons from the lattice structure of an optic before causing thermal damage. Note that the guideline presented here assumes room temperature operation and optics in new condition (i.e., within scratch-dig spec, surface free of contamination, etc.). Because dust or other particles on the surface of an optic can cause damage at lower thresholds, we recommend keeping surfaces clean and free of debris. For more information on cleaning optics, please see our Optics Cleaning tutorial.

Testing Method

Thorlabs' LIDT testing is done in compliance with ISO/DIS 11254 and ISO 21254 specifications.

First, a low-power/energy beam is directed to the optic under test. The optic is exposed in 10 locations to this laser beam for 30 seconds (CW) or for a number of pulses (pulse repetition frequency specified). After exposure, the optic is examined by a microscope (~100X magnification) for any visible damage. The number of locations that are damaged at a particular power/energy level is recorded. Next, the power/energy is either increased or decreased and the optic is exposed at 10 new locations. This process is repeated until damage is observed. The damage threshold is then assigned to be the highest power/energy that the optic can withstand without causing damage. A histogram such as that below represents the testing of one BB1-E02 mirror.

LIDT metallic mirror
The photograph above is a protected aluminum-coated mirror after LIDT testing. In this particular test, it handled 0.43 J/cm2 (1064 nm, 10 ns pulse, 10 Hz, Ø1.000 mm) before damage.
LIDT BB1-E02
Example Test Data
Fluence # of Tested Locations Locations with Damage Locations Without Damage
1.50 J/cm2 10 0 10
1.75 J/cm2 10 0 10
2.00 J/cm2 10 0 10
2.25 J/cm2 10 1 9
3.00 J/cm2 10 1 9
5.00 J/cm2 10 9 1

According to the test, the damage threshold of the mirror was 2.00 J/cm2 (532 nm, 10 ns pulse, 10 Hz, Ø0.803 mm). Please keep in mind that these tests are performed on clean optics, as dirt and contamination can significantly lower the damage threshold of a component. While the test results are only representative of one coating run, Thorlabs specifies damage threshold values that account for coating variances.

Continuous Wave and Long-Pulse Lasers

When an optic is damaged by a continuous wave (CW) laser, it is usually due to the melting of the surface as a result of absorbing the laser's energy or damage to the optical coating (antireflection) [1]. Pulsed lasers with pulse lengths longer than 1 µs can be treated as CW lasers for LIDT discussions.

When pulse lengths are between 1 ns and 1 µs, laser-induced damage can occur either because of absorption or a dielectric breakdown (therefore, a user must check both CW and pulsed LIDT). Absorption is either due to an intrinsic property of the optic or due to surface irregularities; thus LIDT values are only valid for optics meeting or exceeding the surface quality specifications given by a manufacturer. While many optics can handle high power CW lasers, cemented (e.g., achromatic doublets) or highly absorptive (e.g., ND filters) optics tend to have lower CW damage thresholds. These lower thresholds are due to absorption or scattering in the cement or metal coating.

Linear Power Density Scaling

LIDT in linear power density vs. pulse length and spot size. For long pulses to CW, linear power density becomes a constant with spot size. This graph was obtained from [1].

Intensity Distribution

Pulsed lasers with high pulse repetition frequencies (PRF) may behave similarly to CW beams. Unfortunately, this is highly dependent on factors such as absorption and thermal diffusivity, so there is no reliable method for determining when a high PRF laser will damage an optic due to thermal effects. For beams with a high PRF both the average and peak powers must be compared to the equivalent CW power. Additionally, for highly transparent materials, there is little to no drop in the LIDT with increasing PRF.

In order to use the specified CW damage threshold of an optic, it is necessary to know the following:

  1. Wavelength of your laser
  2. Beam diameter of your beam (1/e2)
  3. Approximate intensity profile of your beam (e.g., Gaussian)
  4. Linear power density of your beam (total power divided by 1/e2 beam diameter)

Thorlabs expresses LIDT for CW lasers as a linear power density measured in W/cm. In this regime, the LIDT given as a linear power density can be applied to any beam diameter; one does not need to compute an adjusted LIDT to adjust for changes in spot size, as demonstrated by the graph to the right. Average linear power density can be calculated using the equation below. 

The calculation above assumes a uniform beam intensity profile. You must now consider hotspots in the beam or other non-uniform intensity profiles and roughly calculate a maximum power density. For reference, a Gaussian beam typically has a maximum power density that is twice that of the uniform beam (see lower right).

Now compare the maximum power density to that which is specified as the LIDT for the optic. If the optic was tested at a wavelength other than your operating wavelength, the damage threshold must be scaled appropriately. A good rule of thumb is that the damage threshold has a linear relationship with wavelength such that as you move to shorter wavelengths, the damage threshold decreases (i.e., a LIDT of 10 W/cm at 1310 nm scales to 5 W/cm at 655 nm):

CW Wavelength Scaling

While this rule of thumb provides a general trend, it is not a quantitative analysis of LIDT vs wavelength. In CW applications, for instance, damage scales more strongly with absorption in the coating and substrate, which does not necessarily scale well with wavelength. While the above procedure provides a good rule of thumb for LIDT values, please contact Tech Support if your wavelength is different from the specified LIDT wavelength. If your power density is less than the adjusted LIDT of the optic, then the optic should work for your application. 

Please note that we have a buffer built in between the specified damage thresholds online and the tests which we have done, which accommodates variation between batches. Upon request, we can provide individual test information and a testing certificate. The damage analysis will be carried out on a similar optic (customer's optic will not be damaged). Testing may result in additional costs or lead times. Contact Tech Support for more information.

Pulsed Lasers

As previously stated, pulsed lasers typically induce a different type of damage to the optic than CW lasers. Pulsed lasers often do not heat the optic enough to damage it; instead, pulsed lasers produce strong electric fields capable of inducing dielectric breakdown in the material. Unfortunately, it can be very difficult to compare the LIDT specification of an optic to your laser. There are multiple regimes in which a pulsed laser can damage an optic and this is based on the laser's pulse length. The highlighted columns in the table below outline the relevant pulse lengths for our specified LIDT values.

Pulses shorter than 10-9 s cannot be compared to our specified LIDT values with much reliability. In this ultra-short-pulse regime various mechanics, such as multiphoton-avalanche ionization, take over as the predominate damage mechanism [2]. In contrast, pulses between 10-7 s and 10-4 s may cause damage to an optic either because of dielectric breakdown or thermal effects. This means that both CW and pulsed damage thresholds must be compared to the laser beam to determine whether the optic is suitable for your application.

Pulse Duration t < 10-9 s 10-9 < t < 10-7 s 10-7 < t < 10-4 s t > 10-4 s
Damage Mechanism Avalanche Ionization Dielectric Breakdown Dielectric Breakdown or Thermal Thermal
Relevant Damage Specification No Comparison (See Above) Pulsed Pulsed and CW CW

When comparing an LIDT specified for a pulsed laser to your laser, it is essential to know the following:

Energy Density Scaling

LIDT in energy density vs. pulse length and spot size. For short pulses, energy density becomes a constant with spot size. This graph was obtained from [1].

  1. Wavelength of your laser
  2. Energy density of your beam (total energy divided by 1/e2 area)
  3. Pulse length of your laser
  4. Pulse repetition frequency (prf) of your laser
  5. Beam diameter of your laser (1/e2 )
  6. Approximate intensity profile of your beam (e.g., Gaussian)

The energy density of your beam should be calculated in terms of J/cm2. The graph to the right shows why expressing the LIDT as an energy density provides the best metric for short pulse sources. In this regime, the LIDT given as an energy density can be applied to any beam diameter; one does not need to compute an adjusted LIDT to adjust for changes in spot size. This calculation assumes a uniform beam intensity profile. You must now adjust this energy density to account for hotspots or other nonuniform intensity profiles and roughly calculate a maximum energy density. For reference a Gaussian beam typically has a maximum energy density that is twice that of the 1/e2 beam.

Now compare the maximum energy density to that which is specified as the LIDT for the optic. If the optic was tested at a wavelength other than your operating wavelength, the damage threshold must be scaled appropriately [3]. A good rule of thumb is that the damage threshold has an inverse square root relationship with wavelength such that as you move to shorter wavelengths, the damage threshold decreases (i.e., a LIDT of 1 J/cm2 at 1064 nm scales to 0.7 J/cm2 at 532 nm):

Pulse Wavelength Scaling

You now have a wavelength-adjusted energy density, which you will use in the following step.

Beam diameter is also important to know when comparing damage thresholds. While the LIDT, when expressed in units of J/cm², scales independently of spot size; large beam sizes are more likely to illuminate a larger number of defects which can lead to greater variances in the LIDT [4]. For data presented here, a <1 mm beam size was used to measure the LIDT. For beams sizes greater than 5 mm, the LIDT (J/cm2) will not scale independently of beam diameter due to the larger size beam exposing more defects.

The pulse length must now be compensated for. The longer the pulse duration, the more energy the optic can handle. For pulse widths between 1 - 100 ns, an approximation is as follows:

Pulse Length Scaling

Use this formula to calculate the Adjusted LIDT for an optic based on your pulse length. If your maximum energy density is less than this adjusted LIDT maximum energy density, then the optic should be suitable for your application. Keep in mind that this calculation is only used for pulses between 10-9 s and 10-7 s. For pulses between 10-7 s and 10-4 s, the CW LIDT must also be checked before deeming the optic appropriate for your application.

Please note that we have a buffer built in between the specified damage thresholds online and the tests which we have done, which accommodates variation between batches. Upon request, we can provide individual test information and a testing certificate. Contact Tech Support for more information.


[1] R. M. Wood, Optics and Laser Tech. 29, 517 (1998).
[2] Roger M. Wood, Laser-Induced Damage of Optical Materials (Institute of Physics Publishing, Philadelphia, PA, 2003).
[3] C. W. Carr et al., Phys. Rev. Lett. 91, 127402 (2003).
[4] N. Bloembergen, Appl. Opt. 12, 661 (1973).

In order to illustrate the process of determining whether a given laser system will damage an optic, a number of example calculations of laser induced damage threshold are given below. For assistance with performing similar calculations, we provide a spreadsheet calculator that can be downloaded by clicking the button to the right. To use the calculator, enter the specified LIDT value of the optic under consideration and the relevant parameters of your laser system in the green boxes. The spreadsheet will then calculate a linear power density for CW and pulsed systems, as well as an energy density value for pulsed systems. These values are used to calculate adjusted, scaled LIDT values for the optics based on accepted scaling laws. This calculator assumes a Gaussian beam profile, so a correction factor must be introduced for other beam shapes (uniform, etc.). The LIDT scaling laws are determined from empirical relationships; their accuracy is not guaranteed. Remember that absorption by optics or coatings can significantly reduce LIDT in some spectral regions. These LIDT values are not valid for ultrashort pulses less than one nanosecond in duration.

Intensity Distribution
A Gaussian beam profile has about twice the maximum intensity of a uniform beam profile.

CW Laser Example
Suppose that a CW laser system at 1319 nm produces a 0.5 W Gaussian beam that has a 1/e2 diameter of 10 mm. A naive calculation of the average linear power density of this beam would yield a value of 0.5 W/cm, given by the total power divided by the beam diameter:

CW Wavelength Scaling

However, the maximum power density of a Gaussian beam is about twice the maximum power density of a uniform beam, as shown in the graph to the right. Therefore, a more accurate determination of the maximum linear power density of the system is 1 W/cm.

An AC127-030-C achromatic doublet lens has a specified CW LIDT of 350 W/cm, as tested at 1550 nm. CW damage threshold values typically scale directly with the wavelength of the laser source, so this yields an adjusted LIDT value:

CW Wavelength Scaling

The adjusted LIDT value of 350 W/cm x (1319 nm / 1550 nm) = 298 W/cm is significantly higher than the calculated maximum linear power density of the laser system, so it would be safe to use this doublet lens for this application.

Pulsed Nanosecond Laser Example: Scaling for Different Pulse Durations
Suppose that a pulsed Nd:YAG laser system is frequency tripled to produce a 10 Hz output, consisting of 2 ns output pulses at 355 nm, each with 1 J of energy, in a Gaussian beam with a 1.9 cm beam diameter (1/e2). The average energy density of each pulse is found by dividing the pulse energy by the beam area:

Pulse Energy Density

As described above, the maximum energy density of a Gaussian beam is about twice the average energy density. So, the maximum energy density of this beam is ~0.7 J/cm2.

The energy density of the beam can be compared to the LIDT values of 1 J/cm2 and 3.5 J/cm2 for a BB1-E01 broadband dielectric mirror and an NB1-K08 Nd:YAG laser line mirror, respectively. Both of these LIDT values, while measured at 355 nm, were determined with a 10 ns pulsed laser at 10 Hz. Therefore, an adjustment must be applied for the shorter pulse duration of the system under consideration. As described on the previous tab, LIDT values in the nanosecond pulse regime scale with the square root of the laser pulse duration:

Pulse Length Scaling

This adjustment factor results in LIDT values of 0.45 J/cm2 for the BB1-E01 broadband mirror and 1.6 J/cm2 for the Nd:YAG laser line mirror, which are to be compared with the 0.7 J/cm2 maximum energy density of the beam. While the broadband mirror would likely be damaged by the laser, the more specialized laser line mirror is appropriate for use with this system.

Pulsed Nanosecond Laser Example: Scaling for Different Wavelengths
Suppose that a pulsed laser system emits 10 ns pulses at 2.5 Hz, each with 100 mJ of energy at 1064 nm in a 16 mm diameter beam (1/e2) that must be attenuated with a neutral density filter. For a Gaussian output, these specifications result in a maximum energy density of 0.1 J/cm2. The damage threshold of an NDUV10A Ø25 mm, OD 1.0, reflective neutral density filter is 0.05 J/cm2 for 10 ns pulses at 355 nm, while the damage threshold of the similar NE10A absorptive filter is 10 J/cm2 for 10 ns pulses at 532 nm. As described on the previous tab, the LIDT value of an optic scales with the square root of the wavelength in the nanosecond pulse regime:

Pulse Wavelength Scaling

This scaling gives adjusted LIDT values of 0.08 J/cm2 for the reflective filter and 14 J/cm2 for the absorptive filter. In this case, the absorptive filter is the best choice in order to avoid optical damage.

Pulsed Microsecond Laser Example
Consider a laser system that produces 1 µs pulses, each containing 150 µJ of energy at a repetition rate of 50 kHz, resulting in a relatively high duty cycle of 5%. This system falls somewhere between the regimes of CW and pulsed laser induced damage, and could potentially damage an optic by mechanisms associated with either regime. As a result, both CW and pulsed LIDT values must be compared to the properties of the laser system to ensure safe operation.

If this relatively long-pulse laser emits a Gaussian 12.7 mm diameter beam (1/e2) at 980 nm, then the resulting output has a linear power density of 5.9 W/cm and an energy density of 1.2 x 10-4 J/cm2 per pulse. This can be compared to the LIDT values for a WPQ10E-980 polymer zero-order quarter-wave plate, which are 5 W/cm for CW radiation at 810 nm and 5 J/cm2 for a 10 ns pulse at 810 nm. As before, the CW LIDT of the optic scales linearly with the laser wavelength, resulting in an adjusted CW value of 6 W/cm at 980 nm. On the other hand, the pulsed LIDT scales with the square root of the laser wavelength and the square root of the pulse duration, resulting in an adjusted value of 55 J/cm2 for a 1 µs pulse at 980 nm. The pulsed LIDT of the optic is significantly greater than the energy density of the laser pulse, so individual pulses will not damage the wave plate. However, the large average linear power density of the laser system may cause thermal damage to the optic, much like a high-power CW beam.


Posted Comments:
王 重阳  (posted 2020-10-10 13:21:22.023)
Hi, I want to lengenth the cable of the Galvo scanning system (GVS112M) using the home-made cables. Does it matter ?
cwright  (posted 2020-10-14 09:43:36.0)
Response from Charles at Thorlabs: Hello and thank you for your query. The cable from the driver board to the galvo motor can be extended and we can provide extension cables, but the driver board would usually require recalibration. Their performance is sensitive to being correctly calibrated and extension cables may lower performance (increase settle time) while poor calibration could even lead to damage. We would advise that your galvo be returned to us to have our extension cables fitted and the drivers correctly calibrated. Your local technical support team will reach out to you about this.
user  (posted 2020-04-21 13:25:56.26)
Hi, I was wondering if the mirror of a Single-Axis Scanning Galvo System can be replaced if it gets damaged?
DJayasuriya  (posted 2020-04-22 09:37:05.0)
Response from Dinuka at Thorlabs: Thank you for your query. Yes we can replace the mirror if it gets damaged. We would have to calibrate the galvo after replacing mirror. Please get in touch with your local techsupport team if you would like to arrange this. Thank you.
Simon Ameer-Beg  (posted 2020-03-17 10:43:09.24)
Hi, I have a very specific question. Would it be possible to order the GVS011 with a mirror which is double sided? I.e. coated on both front and back faces? The same Protected silver coating on both sides. Best wishes Simon
DJayasuriya  (posted 2020-03-18 06:13:25.0)
Response from Dinuka at Thorlabs: Thank you for your query Simon. We will contact you for further information.
wei wang  (posted 2020-02-19 23:13:28.63)
Hi there: For storm applications with laser power 50mw-100mw (diameter 5mm), does the galvo with broadband coating sustain this? I wei
AManickavasagam  (posted 2020-02-24 10:30:07.0)
Response from Arunthathi at Thorlabs: Thanks for your query. We will contact you for further information on your laser specs to determine compatibility.
yancheng  (posted 2018-11-24 15:11:17.48)
Hi, I want to buy the GVS411, but I'm not sure whether it is compatible to my laser. Would you please give me a hand? Thank you! email: yancheng@umich.edu tel: 7348813105
AManickavasagam  (posted 2018-11-26 07:46:04.0)
Response from Arunthathi at Thorlabs: Thanks for your query. As a guideline the damage threshold we state for GVS411 would be 0.3 J/cm2 at 355 nm(10 ns, 10 Hz, Ø0.381 mm). I will contact you directly to discuss your laser specs.
modam  (posted 2017-05-30 12:42:02.26)
Dear Sir or Madam, I have different questions about the Single-Axis Scanning Galvo Systems. I would like to rotate a nonlinear crystal (5x5x10 mm, 2 g) over a range of 1° at a frequency of 50 Hz. The angular position and speed have to be defined with a with a specific function from a DAQ. A galvo motors has a high potential for this application. Could you explain me how the mirror is mounted on the galvo motor and how it can be removed ? Can you made a custummized mount the crystal described above ? I would also appreciate if you can give me more details about the control of the acceleration of the rotor, how do we manage to tune the current in order to control it ? Best regards, Morgan Mathez Morgan David Mathez PhD student Optical Sensor Technology DTU Fotonik Technical University of Denmark Department of Photonics Engineering Frederiksborgvej 399 Building 108, Room S67 4000 Roskilde modam@fotonik.dtu.dk www.dtu.dk/english
bwood  (posted 2017-06-01 06:39:32.0)
Response from Ben at Thorlabs: Thank you for contacting us with this interesting proposal. This system may be possible, however there are a few design challenges. The galvo system is very sensitive to the load on the motor; even different mirrored coatings can affect the calibration of the galvo. You would probably need a new mounting solution as well. I believe you have also contacted tech support directly, and I will continue the conversation there.
tom-knop  (posted 2017-02-09 04:20:16.113)
Hi, I would like to have some information about the tuning procedure. I don't really want to change the settings, but it is more for testing purposes. Is there any kind of test pattern that I can display and if so, what software do I need to do this? With kind regards, tom Knop
bhallewell  (posted 2017-02-24 06:03:39.0)
Response from Ben at Thorlabs: Each of our galvo systems is an analogue system & so cannot be tuned directly via software. We tune the signal response of each unit in-house by adjusting the various potentiometers on the galvo drive card board. This is a complex procedure which we don't wish for customers to perform. In terms of checking the performance of the galvo, there is a diagnostics terminal detailed on page. 18 which can be checked to cross-check your input signal with the response from your galvo. I will contact you directly to address your concerns. https://www.thorlabs.com/drawings/d4f04ca7120fbd19-5A9767FF-5056-0103-79303B4BEFD57D8C/GVS002-Manual.pdf
ns.park  (posted 2016-11-22 16:57:55.58)
Hello, I am Nam Su Park in Pusan National University, Korea. Where can I ZEMAX file about GVS011/M? If you offer the ZEMAX file of GVS011/M, I would like to get from you. I can't find ZEMAX file on your website. Please confirm my message and I will wait your reply. Sincerely, Nam Su Park.
bwood  (posted 2016-11-22 07:06:04.0)
Response from Ben at Thorlabs: Thank you for your question. Unfortunately, we do not currently have Zemax files available for our galvo systems. However, the mirrors are flat mirrors, using our standard optical coatings, so you may be able to adpat the files of our single mirrors as an alternative. Please contact your local tech support office, if you would like additional advice on how to do this.
kthering  (posted 2014-09-29 09:33:22.51)
Does the orientation of the motor/mirror assembly effect the performance and/or the reliability? I am possibly planning on mounting the assembly so the motor would be on the top. Thanks
bhallewell  (posted 2014-10-01 11:56:49.0)
Response from Ben at Thorlabs: Thank you for your enquiry. We only spec the performance of this item for table-mounted use however would state that altering the orientation of the motors would not have a significant impact on the performance of the Galvo system.
misanchez  (posted 2014-02-03 10:42:26.887)
Dear Sir/madam We are a company called Flightech systems Europe, from Sapin. We are interesting on buying the galvo GVS011/M for a laser application in 1550 nm. So we are asking for a quotation of this product in order to send it to our purchase departmen. Also it would be nice if you can stelling us the delivering time and Would you mind telling us the scaning speed the system is able to achieve (in mm/s)? Thank you very much.
msoulby  (posted 2014-02-04 09:04:44.0)
Response from Mike at Thorlabs: As our German office is your local office they will contact you directly with the quotation you requested, we have these in stock at the moment so can ship one as soon as you send us your order. In terms of speed it would be difficult to give you a value in terms of mm/s as it would depend on how far away the galvo is from the target of your scanned beam. We do however specify a full scale band width of 130Hz for a sine wave and 65Hz for a square wave; this is for the full 40 degrees travel range of the galvo.

1-Axis Large Beam Diameter Scanning Galvo Systems

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
GVS411 Support Documentation
GVS411Customer Inspired! 1D Large Beam (10 mm) Diameter Galvo System, UV Enhanced Aluminum Mirror, Power Supply Not Included
$1,812.69
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GVS211 Support Documentation
GVS211Customer Inspired! 1D Large Beam (10 mm) Diameter Galvo System, Broadband Mirror (-E02), Power Supply Not Included
$2,030.11
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GVS011 Support Documentation
GVS0111D Large Beam (10 mm) Diameter Galvo System, Silver-Coated Mirror, Power Supply Not Included
$1,715.78
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GVS311 Support Documentation
GVS311Customer Inspired! 1D Large Beam (10 mm) Diameter Galvo System, Dual Band Mirror 532 nm/1064 nm (-K13), Power Supply Not Included
$2,235.72
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GVS111 Support Documentation
GVS111Customer Inspired! 1D Large Beam (10 mm) Diameter Galvo System, Gold-Coated Mirror, Power Supply Not Included
$1,812.69
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GVS411/M Support Documentation
GVS411/MCustomer Inspired! 1D Large Beam (10 mm) Diameter Galvo System, UV Enhanced Aluminum Mirror, Metric, Power Supply Not Included
$1,812.69
3 weeks
GVS211/M Support Documentation
GVS211/MCustomer Inspired! 1D Large Beam (10 mm) Diameter Galvo System, Broadband Mirror (-E02), Metric, Power Supply Not Included
$2,030.11
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GVS011/M Support Documentation
GVS011/M1D Large Beam (10 mm) Diameter Galvo System, Silver-Coated Mirror, Metric, Power Supply Not Included
$1,715.78
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GVS311/M Support Documentation
GVS311/MCustomer Inspired! 1D Large Beam (10 mm) Diameter Galvo System, Dual Band Mirror 532 nm/1064 nm (-K13), Metric, Power Supply Not Included
$2,235.72
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GVS111/M Support Documentation
GVS111/MCustomer Inspired! 1D Large Beam (10 mm) Diameter Galvo System, Gold-Coated Mirror, Metric, Power Supply Not Included
$1,812.69
Lead Time

Galvo System Linear Power Supplies

  • Compatible with Galvo Systems Above
  • Low Noise, Linear Supply Minimizes Electrical Interference
  • Capable of Powering Two Server Driver Cards Simultaneously
  • Configured for Regional Voltage Requirements upon Shipping

These power supplies are low noise, linear supplies designed to minimize electrical interference for maximum system resolution. They deliver ±15 VDC at 3 A and are configured to accept a mains voltage of 115 VAC (for GPS011-US), 230 VAC (for GPS011-EC), or 100 VAC (for GPS011-JP). Each power supply is compatible with all of our galvo systems available above. Two 2 m (6.5') power cables are included.

As an alternative, a standard switching mode power supply may be used for low demand applications.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
GPS011-US Support Documentation
GPS011-US1D or 2D Galvo System Linear Power Supply, 115 VAC
$571.52
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GPS011-EC Support Documentation
GPS011-EC1D or 2D Galvo System Linear Power Supply, 230 VAC
$571.52
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GPS011-JP Support Documentation
GPS011-JP1D or 2D Galvo System Linear Power Supply, 100 VAC
$571.52
3 weeks

Galvo Mount Heatsink and Post Mounting Adapter


Click to Enlarge

2D Galvo System Mounted on Heatsink on a Ø1/2" Post
  • Provides Additional Cooling to Prevent Thermal Cutout
  • Attaches Directly to the 1D and 2D Mirror Mounts
  • Convenient Post Adapter to Thorlabs’ 8-32 (M4) Threaded Posts

The GHS003 galvo mirror heatsink attaches directly to the single-axis and dual-axis mirror mounts to provide device cooling and alternate mounting options. Mounting screws are supplied with the unit.

Heat from the galvo mirrors is typically dissipated through the normal mounting options. However, applications involving rapidly changing drive signals can create excess heat buildup, causing the galvo motor to fail or driver board thermal cutout to trip. If the cutout occurs repeatedly, we recommend using the GHS003 Heatsink. The heatsink also serves as a post adapter, allowing the galvo mirror assembly to be mounted on our Ø1/2" 8-32 (M4) threaded posts.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
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GHS003 Support Documentation
GHS003Galvo Heatsink and Post Mounting Adapter, Imperial
$31.45
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GHS003/M Support Documentation
GHS003/MGalvo Heatsink and Post Mounting Adapter, Metric
$31.45
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Galvo Driver Card Cover

GCM012 in a 30 mm Cage System
Click to Enlarge

The GCE001 can be used to cover the Galvo Systems' servo driver boards.

The GCE001 is a convenient enclosure for servo driver cards. Simply bolt it onto the servo driver bracket using the M3 screws and hex key supplied.

Note: This item is not compatible with early models of the servo driver card. Contact Tech Support for more details.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
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GCE001 Support Documentation
GCE001Galvo Driver Card Cover
$67.65
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