Results
Included are two screenshots from a recent test using the ModeCheck device from Ophir-Spiricon.

The screens below show a comparison of a II-VI MP5 lens and Ophir Optics Black Magic lens.

Laser System
Fiber laser source

• 1070nm
• 600μm fiber
• CW
• 1 KW max average power

5-axis movement
Class 1 workstation
125mm focusing lens

Introduction
Profiling lasers with powers in the 10mW to 1W range is becoming more common. Many of these lasers are in the visible spectrum, allowing them to be measured with CCD and CMOS camera systems. As with any laser that is being measured with a camera array, the beam needs to be attenuated, but there are some cautions to be observed. These beams are not so powerful that they will damage or destroy typical absorptive filters. In fact, it is possible to stack up a sufficient optical density to reduce the power of a 1W laser to the pW levels that will not saturate the detector. Unfortunately doing this will more than likely result in erroneous measurements. This is due to a phenomenon called thermal lensing, or thermal blooming. The laser’s energy heats the local area of the absorptive filter, changing its optical properties. These changes often result in changes to the refractive index of the substrate, forming a lens that may either focus or expand the beam. At lower powers, this phenomenon can be observed over discernable timeframe, hence the term “blooming.” However, it may also occur almost instantly, giving the illusion of stability and accurate measurements.

Aligning the output of laser diode or fiber optic arrays can be quite challenging. One of the lesser known features of the Photon NanoScan slit profilers is the multibeam analysis capability. The NanoScan software allows the characterization of up to 16 simultaneous beams entering the aperture, allowing the user to examine and evaluate various standard beam parameters displayed within the automatically-determined or user-defined regions-of-interest (ROI) on any or all beams captured by NanoScan. This unique control and selection feature gives the user flexibility to single out one beam or to view the entire beam set. Multiple beam data is displayed on the screen and can be isolated in contiguous beam sections as they are collected.

Laser System

• Fiber Source:
• 1070nm
• 400 µm Spot / Fiber
• CW
• 4 kW Max Average Power
• Precitech Welding Head
• 5 Degree Angle
• 300mm fl Lens
• X,Y and Z Motion Control
• Open Class 1 Workstation

One of the recent developments in the photonics industry has been the rapid increase in automated solar panel production facilities.1 Many of these end-to-end production lines use laser-based methods to manufacture the thin film silicon photovoltaic modules. The lasers used for this activity are generally diode-pumped solid-state lasers at 1064nm, 532nm and 355nm with beams focused to around 30μm.2 They are run at powers or energies3 that, although not extremely high, have high power or energy densities at these small beam diameters. The techniques used often call for multiple beams, running in parallel, to make precise cuts to electrically isolate the sections of the photovoltaic sheets. To ensure that these cuts are uniform, it is important to measure the beam profiles.

Many forces drive the miniaturization of optical component technology. Integration of optical components into smaller packages is expected to reduce size constraints, insertion loss, and manufacturing costs. Many ambitious business plans are based on this integrated technology, as it seems amiable to high volume manufacturing methods similar to those found in the semiconductor industry. However, there are numerous technical hurdles to overcome before this Holy Grail is attained.

This year we are celebrating the 50-year anniversary of the laser. Lasers have proven one of the most promising technologies, yet there is still farther to go. With the advancements come more complex and “focused” (no pun intended) laser applications. In some cases, especially with industrial laser processes, it’s getting to the point where the end user -- whether it be the process engineer, quality personnel, or maintenance technician -- must dedicate more and more time to studying laser technologies in order to truly understand the way lasers are being applied. Companies who supply laser beam characterization products have also been diligently developing these technologies in order to continue to provide the best real-world solutions possible.

If you have been in the laser cutting business long enough you eventually will have one of those days when, no matter what you do, the laser will not cut your parts cleanly…if at all. The operators and maintenance personnel check and verify all the usual problem areas and finally conclude that everything looks, measures, and appears correct.

What happens when your company's new laser fails to perform according to specifications and your best customers are waiting weeks for delivery? Does the manufacturer send a field service engineer repeatedly to check for problems? What happens when the manufacturer cannot tell you what is wrong after they finally send their corporate, factory-level engineers to investigate? Do you demand a full refund if the laser still won't work properly and weeks are passing by? What if you spent a fortune in acquisition, setup, training and labor costs and you thought that you bought the best product available on the market?

Problem: What happens when your company's new laser fails to perform
according to specifications and your best customers are waiting weeks for
delivery? Does the manufacturer send a field service engineer repeatedly to
check for problems? What happens when the manufacturer cannot tell you what
is wrong after they finally sent their corporate, factory-level engineers to
investigate? Do you demand a full refund if the laser still won't work properly and
weeks are passing by? What if you spent a fortune in acquisition, setup, training
and labor costs and you thought that you bought the best product available on the
market?

The business objectives in the title of this article are standard in all types of manufacturing, and laser-assisted fabrication is no exception. A set of tools has become available in the past few years that allows end users of industrial lasers to optimize the laser process while complying with current ISO and AWS technical standards. This helps manufacturers remain competitive in the US and in the global markets.

The EarthCARE (Earth Clouds, Aerosols and Radiation Explorer) mission is a joint European-Japanese mission addressing the need for a better understanding of the interactions between cloud, radiative and aerosol processes that play a role in climate regulation. Enzo Nava, Head of the Electro-optics Section at CESI, reports. “We had to produce a pre-development model for the Atmospheric LIDAR (ATLID) laser transmitter to operate. In this case, we were developing an end-pumped Nd:YAG MOPA laser system with frequency tripling to operate at 355 nm.

Reason #1 To Save Money!

Reason #2 For More Accurate and Reliable Laser Research

Reason #3 For Better Laser Design

So why Spiricon's LBA-100A instead of one of those other guys?

Industrial Applications Of Seeing The Laser Beam 

One of Spiricon's sales representatives recently gave a demonstration of the LBA-100A Advanced Laser Beam Analyzer on an industrial YAG laser. The customer has 10 YAG lasers for cutting and welding. They were getting unacceptable variations in the quality of the trim from two of the machines, and wanted to see if the LBA-100A would help them quantify their beam quality. Following is his report on the demonstration:

"We measured the beam after the point of focus, as it diverges, to an approximate diameter of 1/4". This gave us excellent results. On one laser giving problems we could see a near Gaussian distribution with a clip etch on one side. Even though the beam appeared uniform to them under viewing of an IR viewer, and burn paper showed nearly round patterns, it was obvious with the LBA-100A that there were problems. On a second laser system where they were seeing good cuts, we saw a perfectly uniform, near Gaussian beam".

Most laser engineers and scientists are familiar with beam width, position, divergence angle, Gaussian fit, and such parameters for characterizing a laser beam. M² enables a user to quantitatively evaluate the focusability of the laser beam. It is a measure of how close an actual beam is to a perfect Gaussian single mode beam and is very easy to use in predicting the focused spot properties.

With increasingly sophisticated applications, the demands on the quality of the laser beam have become much greater. Traditional methods of measuring laser beam intensity profile; i.e., burn spots, mode burns, and viewing the reflected beam, are woefully inadequate for assuring the laser quality needed for today's applications. Indeed, lasers are becoming of increasingly high quality. To a large extent this is due to the availability of electronic beam profile instruments. These instruments provide a real time view of the laser beam profile that provides infinitely greater intuition to enable laser optimization. Also, electronic laser beam profilers produce much more accurate quantification of laser beam properties. The accuracy of these measurements enables scientists to fine tune the laser properties to a greater extent than previously possible. New algorithms for laser beam property quantification are discussed, along with the performance improvement of these calculations. In addition, examples are presented of actual situations in which viewing the laser beam has significantly improved its performance.

Laser processing puts increasing demands on beam quality for the process to be cost-competitive. Merely profiling the beam and comparing the profile to a Gaussian fit is no longer adequate, because it does not guarantee a diffraction-limited beam. A 'Gaussian fit' calculation can deceive the user into assuming propagation properties that will not exist in practice. Thus, the Gaussian fit method can lull the user into a false sense of security of laser performance.