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.
Beam characterization can be described as using a set of equipment to gather data about a laser beam that is vital to the process in which that laser is used. Such characteristics might include: output power or pulse energy, pulse width and shape, raw beam size or focused spot size, beam mode, as well as several other laser attributes that you could gather with current beam characterization technologies.
As technology evolves, laser specialists must continue to educate themselves in order to be able to proactively maintain their laser systems and ensure the highest quality processes. Part of this continuing education should include the characterization of their beam. The laser specialist should be utilizing any and all tools at their disposal in order to gather as much information about their beam as possible so they can make the most accurate analyses. However, for a number of reasons, laser users, and even in some cases laser manufacturers and integrators, still do not take advantage of the information that beam characterization solutions supply.
Why the Resistance?
There are many end users of lasers who were thrown into this position through one life path or another. They were awarded the task of “making sure that laser ‘thing’ is working right.” A company with a laser in its manufacturing process will usually work with a laser manufacturer or integrator to develop a laser process, but since most of the development will happen outside of the end user’s facility, the laser will be installed and put online and can often be treated as a “magic black box” after that. Since a majority of people don’t truly understand laser principals, this can be a great opportunity. Unfortunately, understanding the characteristics of a laser and learning how to apply those characteristics to your processes can be a tedious and often-times frustrating assignment. A lot of those who are assigned this task will equip themselves with “just enough knowledge to be dangerous,” but will still lack a firm grasp on understanding how a laser behaves, as well as what to change and when to change it to achieve optimal process results.
Several industrial laser users have an advanced understanding of the proper application of the laser for which they are responsible. Whether it is through an academic setting, participation in an advanced laser principals and/or maintenance course, or from simply attending the “School of Hard Knocks,” they know how to manipulate a laser to achieve the desired results. Such an individual will probably tell you that it can be a frustrating and time-consuming process, which is magnified when the proper tools are not available. Burn paper, acrylic blocks, mode plates, even power meters can provide some indications about how your laser is performing and feedback during laser tuning practices. However, the information is mostly subject to the technician’s opinion and still may not address the problem of the processes taking too much time to perform.
There are those who are convinced that laser beam characterization is not needed for some industrial laser processes. For instance, it’s been said that, “Hey, if the laser is marking, it’s marking and that’s good enough for me.” Unfortunately, what is forgotten is that often laser components will degrade over time and not monitoring the changing laser behavior over time will result in slower throughput or issues with poor quality. Applying a consistent, thorough, planned maintenance schedule that includes laser beam characterization practices will not only ensure high-quality results, it will ultimately save money by reducing or eliminating scrap and reducing the risk of laser down time due to catastrophic failure of laser components… regardless of the type of laser or process that is applied.
A lot of reputable laser manufacturers are willing to work with end users to help them understand what is important about their manufacturing process with respect to the care and maintenance of their laser. They realize that disclosing the quality of their own product is vital to their competitive edge against other laser manufacturers and they will openly provide beam characterization data to those considering their products. However, some are not willing to support the need for laser beam characterization. It makes one wonder why the beam quality of their product is not being disclosed. In some cases, I’m sure that it is for reasons already discussed in this article. However, as an end user, and even an integrator, this should be carefully considered when establishing relationships with laser manufacturers.
In today’s economic climate, maintaining quality is vital at all stages in the manufacturing process. When quality issues are not addressed, and addressed quickly, a company loses money as well as its competitive advantage. I’m sure that most appreciate the irony that in tougher economic times, the purchasing of the equipment that helps laser engineers maintain high-quality laser processes is often put on hold. It’s quite a gamble. When the planned maintenance practices of the laser technician do not include the monitoring of the laser’s temporal degradation, the result could be reduced throughput, poor quality issues, increased scrap, or laser downtime due to catastrophic failure of laser components. All of these scenarios could easily outweigh the costs of a proactive approach to laser quality monitoring. Often time, it is possible to find an integrator of industrial laser systems who will see the need for beam characterization. They realize that they will save time and money because they’ve addressed laser quality issues and suggested the investment in beam characterization equipment up front instead of being reactive to a situation which involves quality issues on a system they’ve designed and are responsible for maintaining. But again, often these tools are left out of the system to reduce overall cost.
Solutions that Laser Characterization Brings
One concern that arises frequently is, “I’m getting all of this data about my beam, now what?” All the tools in the world won’t help without knowing how to apply the results. Fortunately, there are a fair number of industrial laser experts you can tap into. Industrial laser publications can also be a helpful place to learn. Hopefully, you have a partnership with a laser manufacturer who has a training program where you can learn about their products on an advanced level so that you use these tools to their full potential by understanding how to manipulate the performance of your laser based on the data that you’ve received.
In addition to the resources of laser manufacturers, there are a number of universities which hold short courses on how to maximize and maintain the quality of your laser process. For instance, the University of Wisconsin Madison’s School of Engineering’s Department of Professional Development holds several courses throughout the year which are open to the public. Laser manufacturers also hold their own applications and training courses. Information on these is listed below.
Another set of venues that can give valuable information about laser processes are industrial trade shows. Companies that specialize in providing equipment that helps laser specialists with beam characterization are often more than happy to share tips and techniques. Along with trade shows, another information resource is the conference. Several annual conferences provide a wealth of application information and can provide you with methods of correlating the data that you obtain from your beam with how your laser is applied in your process. Finally, on the academic side, there are symposia put on by different universities around the country which share information on research that is conducted with lasers. Trade shows, conferences, and symposia are a cost-effective yet beneficial way to educate the laser user about beam characterization from specialists who have dedicated their careers to studying laser characteristics and applications. For scientific laser applications, there are shows such as Photonics West and CLEO. For industrial laser applications, there is ICALEO, ALAW, FabTech, and others throughout the year. Links are provided below.
Those in the industry who specialize in providing laser performance measurement solutions are sensitive to the economic challenges that most companies face these days. As a result, beam characterization solutions that are cost-effective have been and will be developed to provide the laser specialist with vital information about his laser.
Research and development of new technologies are continuing in this field and new discoveries and concepts are being applied as quickly as possible to provide the market with the best in beam characterization technology. The end results include power and energy measurement equipment with higher damage thresholds, beam imaging devices with quicker data capture rates and higher resolutions, and state-of-the-art beam analysis software that efficiently utilizes computer hardware and is as simple or complex as you’d like.
At this, the 50-year anniversary, laser technologies don’t show any sign of slowing down. New laser processes, components, and applications are being discovered every day. And the end users of lasers need to keep pace by constantly improving their own knowledge of their laser processes, of new and upcoming laser technology, and of process developments. Part of this education process is the implementation of a sound laser characterization practice. Close monitoring of laser parameters that are key to the process need to be tracked, recorded, and compared over time in order to maintain high laser efficiency and a high-quality laser process.
URL’s for Helpful Sites
Educational Resources UW-Madison: http://epdweb.engr.wisc.edu/laser-processing-welding-courses.lasso
OR Laser: http://www.or-laser.com/en/workshops/employee-training.html
Preco Laser: http://www.precoinc.com/support/training/
Rockwell Laser Institute: http://www.rli.com/training/course.aspx?CourseID=36
SPIE’s Photonics West: http://spie.org/x2584.xml
LIA’s ICALEO: http://www.lia.org/conferences/icaleo/conference
Ophir Photonics Group