Large beam diameter
High beam power
100 mm × 100 mm, 100 W/cm^2
Caution: LaseView 5 is no longer supported, please check the new version here !
Owners of LaseView 5 can get a free update to version 6 ! Please contact us for details.
Former LaseView 5 page as below:
What is LaseView ？
LaseView 5 is a software of laser beam profiler.
- Measurable the beam profiler and diameter
- Installable to many computer that your group has
- Available the low-cost cameras
- Available the low-cost beam monitoring system
- Measurable M2
- Available the free trial version
- Selectable the set options of beam profiler for large diameter and high power
For more details, click LaseView specification.
Fig: LaseView screen
M2 can be easily measured.
|Product name and number||Price|
|Beam profiler withM2 platform software – LaseView 5||US$2,500|
|LaseView 5 “30 days trial“||US$ 0|
* Camera will be needed in measuring beam profile and recommended one are here.
- Measurement of the spatial intensity distribution of the beam
- Measurement of the beam diameter
- Measurement of M2
- Measurement of the micro-beam under 30 μm
- Real-time image averaging features
- Real-time contrast adjustment feature (wide dynamic range of 16bit 65536 tone)
- Image buffer function (able to sequentially display multiple images stored in memory)
- TIFF format image storage function
- Smooth display function by hardware acceleration
- Support 32bit and 64bit Windows
Windows XP SP3
Windows Vista SP1
(This is not to guaranty operation on all computers fitting this description)
Installment of .NET Framework 4 needed (not needed for OSs over Windows 8 for .NET Framework 4.5 is included)
- Line Profile
Line profile display on cross line (with Gauss function, Lorentz function and Sech2 function fitting, and FWHM analysis function)
- Integration Profile
Displaying averaged profile in the horizontal and vertical direction (with analysis function similar line profile)
- Max. Intensity Projection
Display of orthogonal projection (maximum value) profile of horizontal and vertical direction (with analysis function similar line profile)
- Point-Point Distance
Measurement of the distance between any two points on the screen
- Peak Integration
Analysis of the integrated value in a circle and analysis of the light intensity on the cursor setting the outside of the circle as a background
Example of analysis of line profile
Display line profile on the white-cross line.
You can calculate FWHM of the beam profile, and also fit the profile with Gauss, Lorentz, and Sech functions.(The red line is the fitting result by Sech2 function) The white-cross line can be rotated.
The movie below is demonstration of a follow-on function detecting a peak with line profile analysis.
Example of analysis of peak integration
You can analyze the integrated value in a circle setting the outside of the circle as a background.
The circle should be adjusted as the beam is fit inside the circle by modifying the position and size of the circle.
Then clicking “peak ” provide an amplitude of the beam where the white-cross line indicating the peak position(See Fig. 1.4).
The unit of the amplitude is cm2, and the intensity can be obtained by multiplying the amplitude by the laser power.
Fig: Near-field pattern of He-Ne laser
Fig: Far-field pattern of Ti:Sapphire laser
Fig: Focused beam pattern from multi-mode fiber of laser diode
Beam monitoring in laser processing (1 software + 2 camera)
Fig: Beam monitoring in laser processing
Beam monitoring in laser damage test (1 software + 4 camera)
Fig: Beam monitoring in laser damage test
Merit of LaseView
|Conventional profiler||LaseView 5|
|Main sales methods||CCD camera + software||Software|
|Measurable beam diameter||– 35 mm||– 100 mm
|Ｍ2 beam quality measurement function|| ×
|Price for one||$5,000 –||$2,900-
(Software $2,500 + CCD camera price)
|Price for two||$ 10,000-||$3,300-
(Software $2,500 + two CCD camera price)
＋Ｍ2 beam quality measurement function
($5,000 + $5,000)
(Software $2,500 + CCD camera price)
CCD camera is needed to use LaseView 5 as a beam profiler. Recommended cameras are listed below.
DMK 21AU04 from Imaging Source is low cost and recommended.
＊ The camera with trigger is suitable for measurement of pulse laser
＊ The camera without a cover glass is suitable for measurement of CW laser or nanosecond laser.
Imaging Source Inc. USB 2.0 CCD monochrome camera
|Format||Resolution[pixel]||Frame rate||Sensor size||Trigger||cover glass|
|DMK 21AU04||640×480||60 fps||1/4“||–||○|
|DMK 21BU04||640×480||60 fps||1/4“||○||○|
|DMK 31AU03||1024×768||30 fps||1/3“||–||○|
|DMK 31BU03||1024×768||30 fps||1/3“||○||○|
|DMK 41AU02||1280×960||15 fps||1/2“||–||○|
|DMK 41BU02||1280×960||15 fps||1/2“||○||○|
|DMK 51AU02||1600×1200||12 fps||1/1.8“||–||○|
|DMK 51BU02||1600×1200||12 fps||1/1.8“||○||○|
|DMK 51BU02.WG||1600×1200||12 fps||1/1.8“||○||–|
|USB2.0 cable 2m||–||–||–||–||–|
Imaging Source Inc. USB 3.0 CCD monochrome camera
|Format||Resolution [pixel]||Frame rate||Sensor size||Trigger||Cover glass|
|DMK 23U618||640×480||120 fps||1/4“||○||○|
|DMK 23U445||1280×960||30 fps||1/3“||○||○|
|DMK 23U274||1600×1200||20 fps||1/1.8“||○||○|
|USB3.0 cable 2m||–||–||–||–||–|
CMOS camera is lower than CCD camera on cost.
Though CMOS has lower detection range, it has better than CCD on several points including resposivity speed.
USB 3.0 CMOS Monochrome camera by IDS Imaging Development Systems GmbH
|Format||Resolution [pixel]||Frame rate *1||Sensor size||Price|
|UI-3370CP-M-GL||2048 x 2048||80 fps||1“||–|
USB 2.0 CMOS Monochrome camera by Thorlabs, Inc.
|Format||Resolution [pixel]||Frame rate *1||Sensor size||Price|
|DCC1545M||1280 x 1024||25 fps||1/2“||–|
Infrared camera will be needed to observe laser with wavelength over 1100 nm.
Both infrered camera and expanded driver set for LaseView are abailab le.
ARTCAM-008TNIR by ARTRAY Inc.
Interface: USB 2.0
Wavelength: 900-1700 nm
Frame rate: 90 fps
A Beam profiler is a device to measure the beam diameter and the spatial intensity distribution of a laser. Beam diameter and the spatial intensity distribution are the laser characteristics that represent how the laser behaves. For example, even if the two lasers have the same intensity and beam diameter, if the spatial intensity distribution is deferent, the two lasers do not behave the same. Also even with a strictly designed laser resonator, difficult to accurately predict the beam characteristics that can actually be obtained is difficult, dew to manufacturing errors of the optical element and surrounding environment such as temperature. So it is important to actually measure, the properties of the beam.
A beam profiler is used for measuring beam characteristics. There are two main measuring types, fixed type beam profiler and scanning type beam profiler (table 1). Using fixed type beam profiler, it is possible to efficiently measure the beam pattern, because it measures the entire beam at once using a two-dimensional optical sensor. Also it is possible to measure pulse wave and continuous wave. Scanning type beam profiler, uses a single optical detector to measure the light intensity of that moment. Scanning type is a more low cost system than the fixed type. Both methods can measure N.F.P. (near field patter) and F.F.P. (far field pattern) of the beam.
Here we will explain the definition of the beam diameter, then each of the methods of measuring beam profile.
Table Beam characteristic measurement methods
(Advantages and disadvantages of fixed type beam profiler and scanning type beam profiler)
|Fixed type beam profiler
・ＣＣＤ camera type beam profiler
|・Short measuring time
・Can measure pulse light
・Possible to identify complex beam patterns
（such as donut-shaped pr flat-top）
|・For small beam diameters need extra optical device|
|Scanning types beam profiler
・Knife edge type
|・Measurement of small beam diameter is easy||・Long measuring time
・Difficult to measure pule wave
・Identifying complex beam pattern is difficult
Laser beam has a distribution of light intensity in the plane that is perpendicular to the direction of propagation. Light does not have a clear border, so we need to define beam diameter. They are several defining methods, however the most commonly used is the following. In a Gaussian beam, which the intensity distribution is circular symmetry, position of the beam diameter is where the light intensity becomes 1/e2 of the maximum intensity.
The intensity of a Gaussian beam with a light intensity of P, is represented in the following equation.
Figure 1(a) shows the cross section and the intensity profile of the Gaussian beam mentioned in Eq. (1).
The beam diameter is w0. There are also other methods. Such as the method that defines the beam diameter as, where the intensity becomes half of the maximum intensity. This is called full-width half-maximum, FWHM.
The definitions above cannot be easily applied to a laser that has an asymmetric beam shape. With asymmetric beams, the range which has 86.5% of the light intensity is defined as the beam diameter (Fig. 1(b)). With a beam with highly complex form, and is difficult to define the beam diameter, ISO Standard is used. In ISO Standard the beam diameter is defined as, the level where the value of the second moment of the intensity distribution becomes 1/e2.
Fig.１Definition of beam diameter. (a) Gaussian beam (b) beam with a complex form.png
This system measures the light intensity of the whole beam at once, using two-dimensional optical sensors. Because of this, it is more efficient than scanning type beam profiler.
By analyzing the data it is possible to measure beam diameter, beam profile and M2.
For light detection, CCD (charged coupled device), which is a semiconductor device with optical detectors arranged two-dimensionally, is used. When light is irradiated to the CCD, the intensity distribution is recorded by each optical detector. The obtained information is fed in to a computer, and reconstructed as a two-dimensional or three-dimensional intensity distribution image, using a software (Fig. 2).
Spatial resolution is determined by the size of the pixels of the CCD. The size of a general pixel is approximately 10 μm, the diameter of a measurable beam is between a few dozen μm and 100 μm. Measurement time can be speeded up by increasing the speed of discharge and charge of electrons that is stored in the CCD. However in actual monitoring, it is limited to the monitors frame rate (30 fps).
Wavelength that a normal CCD can detect is about 1.1 μm. Because of this, it is not possible to directly detect the beam profile of laser diode radiation used for optical communication that uses 1.3 μm and 1.5 μm. For wavelengths outside the band an image converter that converts infrared light to visible light is used.
Fig. 2 Fixed type beam profiler
It can get the intensity distribution of the entire beam by scanning the pinhole two-dimensionally along the plane perpendicular to the optical axis of the laser beam while measuring the transmitted laser beam intensity (Fig. 3). Making the diameter of the pinhole smaller can increase the spatial resolution. Normally, a pinhole the one hundredth of the beam diameter’s size is used. Because it is possible to measure the intensity distribution of any shape, it is possible to measure a complex beam pattern. It is used to measure the continuous wave with no time variation.
Fig.3 Pinhole-scanning type beam profiler
The same as pinhole type, by scanning the rectangular slit two-dimensionally along the plane perpendicular to the optical axis of the laser beam, the spatial intensity distribution can be measured(Fig. 4). One-dimensional intensity distribution along the scan direction can be obtained. To get a multidimensional intensity distribution, it is necessary to scan from several directions. It is suitable for measuring a beam with an axisymmetric intensity distribution. Narrowing the slit width increases the spatial resolution. It has a high resolution, and can measure a beam diameter down to about 20 μm.
Fig. 4 Slit-scanning type beam profiler
This method uses a blade as an obstacle.
Place the knife at the plane perpendicular to the optical axis of the laser beam, and measure the intensity of the light that passes through (Fig. 5). It measures the intensity diameter distribution by moving the knife along the plane. Unlike the slit type beam profiler, by moving the knife, it changes the light intensity (Fig. 5(b)). At this time, between the one-dimensional spatial intensity distribution i(x) and the measured light intensity i ‘ (x), the following relationship can be established.
Therefor, the spatial intensity distribution can be obtained by simply dividing the measured light intensity by the knife’s axial displacement. The spatial resolution is better than slit type beam profiler, it can measure a beam diameter down to about 10 μm.
Fig. 5 (a) Knife edge type beam profiler
(b) Relation between measured intensity and intensity distribution
In order to know the characteristics of the beam of an optical device such as, laser diodes or optic fibers, it is necessary to measure the following two profiles. The beam profile near the exit end (N.F.P.: near field pattern), and the beam profile far away from the exit end (F.F.P.: far field pattern). Here we will explain how to measure them with a fixed type beam profiler (CCD type).
For the spatial intensity distribution of a micro level (N.F.P.), magnifying optical system such as a microscope (Fig. 6) is used. The exit end is magnified with an objective lens and then focused on the CCD by a relay lens. Since it is a very small beam, accurate focusing is required. This can be easily achieved by, splitting the beam in two using a beam splitter, and feeding one of them in to the monitoring CCD, thus setting the focus position while observing with a wider field of view.
By measuring F.F.P., diffusion angle of laser diode radiation and N.A. of optic fibers can be measured.
To measure F.F.P., an optical system that uses a f-θ lens, which converts the incident angle to the focal position is used (Fig. 7).
Fig. 6 Optical system for measuring N.F.P.
Fig. 7 Optical system for measuring F.F.P.
A M2 beam quality measuring instrument is an instrument that measures laser’s beam quality. Even with a lasers resonator that has the same performance, characteristics of the focused laser beam varies depending on the injection output beam’s characteristics condensing characteristics change.
This is an important parameter, in a field that constant quality is required, such as laser processing. As a measurement of beam quality, the focusing characteristics of a beam, is defined as M2, K value and B.P.P. (beam parameter product).
When condensing focusing laser light with lends, the theoretical minimum spot size is determined by the diffraction limit.
However, if the beams intensity profile is disarranged, the beam cannot be focused the beam to the diffraction limit. M2 is an index to show how many times bigger the beam diameter is to the diffraction limit. If M2 is 1, that beam will have a theoretically minimum focus point. K value is the reciprocal number of M2. B.P.P also has the same meaning as M2, and is shown in the product of the beam divergence angle and the beam waist radius. B.P.P. is mostly used to represent the beam quality of a semiconductor laser diode.
Even with laser beams that have a strong directivity, and seem to be propagating in a straight line, the beam diameter spreads with propagation. The situation near the beam waist of a propagating beam is shown in Fig. 8.
Near the beam waist, the beam radius in the x-axis and y-axis directions wx,y (z) can be given by the following equation.
w0x,0y, z0x,0y, and θ0x,0y shows the beam waist radius at the x-and y-axis directions, the position of the beam waist, and the divergence angle of the beam, respectively. The Mx、y2 here is used as a parameter to determine the beam quality, and has the following properties.
- M2 is always above 1.
- When M2≡1, the beam is a single-mode Gaussian beam.
- M2 shows how many times bigger the beam diameter is to the diffraction limit.
M2 is defined using laser beam parameters as the following.
λ indicates the wavelength of the laser light.
Fig. 8 The state of the vicinity of the beam waist of a Gaussian beam that is centrally symmetric.
As shown in Eq. (4), M2 can be evaluated by measuring the beam waist radius w0 and the divergence angle of the beam θ0. These parameters can be obtained by, focusing the beam and measure measuring beam diameters of several points along the optical axis (Fig. 9). To reduce the error, measuring at many points as possible, especially around the beam waist should be performed. This increases the accuracy of determining the beam waist.
M2 of major laser beams are summarized in Table 2.
Fig.9 Schematics of measuring M2.
Table 2 Quality of major laser beams
|He-Ne laser||< 1.1|
|Ion laser||1.1 ~ 1.3|
|1.1 ~ 1.7|
|High-power multimode laser||3 ~ 4|
National Institute for Fusion Science
The University of Electro-Communications
Tokyo Institute of Technology
Japan Atomic Energy Agency
Helmholtz-Zentrum Dresden-Rossendorf (HZDR)
Institute of Physics AS CR, v.v.i.
Jet Propulsion Laboratory, NASA