Top Laser Measurement Case Studies Across Industries

How we found the right beam profiling solution for a nuclear-powered US Army submarine

This case study follows the journey of the Ophir team, as they worked tirelessly to find the right beam profiling solution for a nuclear-powered submarine.

You’ll find out the winning combination of technologies, tools, and techniques that were used to carry out this challenging task.

The US Army embraces emerging technologies – and so, the Ophir team ended up looking into laser measurements for a laser in the periscope of a 6800 ton, nuclear-powered submarine.

Of course, as with any military application, there are strict requirements to meet. In this case, the laser had to be extremely accurate.

As you can imagine, there are few things more challenging than ensuring high laser accuracy on a moving, underwater vehicle.

This laser operates in conditions with limited inputs - GPS data, and the influence of gravity on its orientation and alignment.

As a result, the quality of the laser beam - and its shape, size, and intensity - all become critical - and beam alignment must be measured with extremely high accuracy.

Finding the right instrumentation for these measurements wasn’t easy!

After several attempts, the Ophir team discovered a winning combination - Ophir-Spiricon BeamGage software, together with the Spiricon SP300 - a high-speed, high-resolution USB3 CCD camera.

Three key measurements were taken - a baseline source beam measurement, the beam’s ellipticity, and the laser source’s Gaussian Fit.

Next, these measurements were repeated at greater distances from the source, to calculate changes, and see if these changes were within tolerance. This method allowed them to capture both qualitative and quantitative differences, so the source could be improved and adjusted.

The beam profiling software proved itself vital for capturing the measurements and images needed. This data was used to identify the critical variables, from both the laser source and the final assembly, which would have an impact on the system.

With the right technologies, techniques, and tools - the team was able to ensure maximum laser system performance for this challenging underwater military application.

Take a look at the original case study – where you’ll see some of the measurements captured, in their graphical form.

Anyone involved in automotive manufacturing knows how crucial it is to be able to weld efficiently and accurately. Especially when laser seam welding sheets of zinc-coated steel, a common occurrence in the industry, there are many challenges – as these metals have disparate melting and evaporation properties.

Let’s explore this case study, which shows how Volkswagen’s team of experts in Wolfsburg took on an exciting research project – to develop a new and unique multi-focal laser welding process.

Project leader and engineer Alexander Franz immediately recognized the importance of measurement technologies in laser process development. The time taken to measure a laser has a direct effect on the overall process development time. To speed up development – the team chose Ophir’s BeamWatch laser measurement instrument.

The idea behind multi-focal laser welding is that several laser beams are generated at once by a laser beam optic, to join hot-dip galvanized sheets in a zero-gap configuration. Using two highly focused forward laser beams, and one welding spot, two and three sheet metal joints can be produced with extremely high seam quality.

What the secret to this impressive result? Keeping the geometry of the laser beams completely in sync – and to do that, you need to measure them. You can read the full case study to find out more about the types of measurements taken.

Ophir’s BeamWatch has unique properties which made it suited for this task – it measures the laser beams without touching them, and allows multiple beams to be measured at once.

Each measurement could be taken and displayed in less than 400 milliseconds. This is a massive improvement when compared to the five minutes or more it would take for each measurement, when using other measurement instruments.

In effect, with the BeamWatch, the team was able to see the results of every tiny change they made to the process in real time. Thanks to this – they developed and refined the new welding process very quickly.

Of course, the automotive industry is not the only application the BeamWatch is suited to – it’s compact, flexible, and easy to set up – making it ideal for troubleshooting and laser process development in any field.

More than 400 million people worldwide suffer from diabetes. For them, the ability to measure blood glucose levels non-invasively (without piercing the skin) would be an enormous relief. Thanks to a patented development by DiaMonTech AG, this dream could soon come true for many people. The technology, which uses an infrared quantum cascade laser, is already available as a desktop device. But a smartphonesized instrument is soon to follow. In order to achieve this miniaturization without loss of quality, it is necessary to detect even minute changes in the laser beam. DiaMonTech used the Ophir Pyrocam to measure and characterize all their laser developments.

Many non-invasive methods for measuring blood glucose have failed because they were not accurate enough: Glucose values in body fluids such as tears, saliva or sweat do not correlate sufficiently with glucose values in blood. The situation is different for skin fluid (interstitial fluid – ISF). Measurements taken on ISF at points with good blood supply correspond well to the actual amount of glucose in the blood. DiaMonTech was founded in 2015, after years of research at the Goethe University Frankfurt. On the basis of this research, the company has developed the first noninvasive blood glucose meter, obtaining CE approval as a medical device in 2019.

The D-Base – as the desktop device is called – works based on infrared spectroscopy, and specifically the principle of photothermic deflection. For this purpose, a quantum cascade laser radiates infrared pulses in wavelengths ranging between 8 and 11μm into the deeper skin layers. The pulses of these wavelengths pass through the sensor element and excite the glucose molecules to oscillate briefly, with the fast relaxation a small amount of heat is given off to the environment. At the skin surface this results in a minimal increase in temperature. In the sensor element, the thermal gradient causes a thermal lens effect. The test beam of a red laser diode is deflected by this thermal lens as it passes through the IRE. The deflection is measured by a position-sensitive photodiode; the device calculates the glucose concentration based on the deflection.

The measuring principle has now been proven in everyday clinical practice, and numerous tests show that the measurements provide reliable results. However, as Sergius Janik, COO at DiaMonTech, explains, shrinking the size of the measuring device is still a challenge: "Diabetes patients want fast and compact measurement technology that they can easily use at home and on the road. This is the focus of all our current research." Only a few manufacturers offer the tunable quantum cascade lasers that DiaMonTech uses for the D-Base. In order to reduce the overall size of the measuring device, the laser must be as small as possible. However, the specific parameters of the laser beam must not be affected by this reduction in size. Even the classic quantum cascade lasers used thus far must meet these specifications exactly.

In order to evaluate the quality of a given quantum cascade laser, the DiaMonTech laboratory conducts detailed measurements on all of them to answer the following questions:
• What does the laser beam profile look like?
• What is the output power of the laser?
• How divergent is the beam?
• What is the pulse repetition rate?
• What is the pulse-to-pulse stability and shape of the pulse?
• How large is the focal spot on the skin?

In the company's early days, the team relied on the knifeedge technique for laser measurement to obtain the beam profiles. But because the number of measuring points required is large, it takes several hours to measure a laser beam this way. Had the company applied this method in the development of its new, compact blood glucose meter, it would have lost a lot of time – and still, the results would not have been precise enough. After in-depth research and conducting an array of tests in their own laboratories, the experts decided on the Ophir Pyrocam-III-HR-C-A-PRO. Using this high-resolution pyroelectric matrix camera, the beam profile of an infrared laser can be measured both quickly and reliably. For the application at DiaMonTech, the camera was individually calibrated to the appropriate signal level. The camera data is then evaluated with the BeamGage software. Output power, beam profile and beam divergence can be determined by the camera in just a few seconds. Sergius Janik explains: "The Ophir Pyrocam is our key measuring device for characterizing the laser beam, and we use it every day. We use it not only for developing new prototypes, but also for quality assessment and troubleshooting. As necessary, we also make the Pyrocam available to our development partners, so they can make precise and reliable adjustments."

Janik describes a concrete application as an example of the enormous time savings achieved by the Pyrocam. During a series of tests conducted by the DiaMonTech lab on a new laser, the engineers were unable to focus the beam. The power distribution of the beam was very irregular, but the cause was not obvious at first glance.

Only the images taken with the Pyrocam provided an explanation. Instead of the desired symmetrical Gaussian beam profile, the beam appeared strongly distorted.

These results showed that the collimating lens of the beam was out of adjustment, which may have occurred during shipment. The laser system was sent back to the manufacturer, the lens was re-adjusted, and then the Pyrocam measurements showed a uniform beam profile.

Another challenge that arises when developing a compact blood glucose meter is the different beam position for any given wavelength. To detect glucose in the skin, it is necessary to take measurements using a variety of wavelengths in the infrared range. But with a tunable laser, as soon as the wavelength is changed, the beam moves (a.k.a. "beam hopping"). As a result, it enters the skin at a slightly different position (up to about ¼ mm) and – analogous to wrongly corrected vision – the thermal lens becomes blurred. When the DiaMonTech team changes the wavelengths, they use the Pyrocam to measure the focus position, which is marked with crosshairs. The BeamGage software records the changes in crosshair position for accurate tracking. The wavelengths that provide the most precise measurements can then be determined, based on the findings from these readings.

Faster measurements mean more efficient development:
Along the road to miniaturization in non-invasive blood glucose monitoring, there is no way around a camerabased measurement of the beam profile. Before purchasing a measuring device, DiaMonTech tested the solutions available on the market. The Ophir measuring device not only had a wavelength range suited to the purpose, it also provided the required performance range and offered very good value for the money. Janik appreciates the measurement technology: "The Pyrocam makes our daily work easier. We no longer waste hours on time-consuming measurements; rather, we get reliable results very quickly. This allows us to concentrate on the essential work of development."

Over the past several years, the fields of aesthetic medicine, surgery and cosmetics have been revolutionized by laser technology. With the development of their innovative laser systems, Asclepion Laser Technologies contributes greatly to patient well-being and faster healing. A consistent measurement strategy, effective testing processes and first-class measuring devices guarantee the high quality of the company's manufacturing at all times. For decades, Asclepion has relied on Ophir measuring technology from MKS Instruments to check the power and energy of the laser beam. To adjust it's PicoStar® laser, the company measures and analyzes the beam profile of this pico-second laser using an Ophir CCD camera combined with a beam reducer.

Asclepion Laser Technologies has been active in the area of international medical laser technology since 1977. The company's home base in the Jena Optical Valley promises – and delivers – extraordinary strength in innovation: The laser systems and their components are developed and manufactured almost entirely in-house. Over the past few years, the breadth of the company's portfolio has grown steadily; today it ranges from CO2 and solid-state lasers for dermatological and surgical procedures to diode lasers, for example for vascular applications and permanent hair removal. And it has expanded its offerings for the field of dermatology with the development of a picosecond laser: The PicoStar laser effectively and gently removes tattoos, permanent makeup and benign pigmentation.

A necessary condition for the great success of Asclepion Laser Technologies is the continued maintenance of strict quality standards. To this end, the company has developed a finely tuned measuring and testing process to which every laser system is subjected before being shipped. It rests on three essential pillars:
• Consistent measuring technology from development through to maintenance
• The right measuring technology for each application
• Meticulous quality inspection, based on the principle of double checks

During production and, above all, during the final inspection of the laser systems, the measured parameters are continually compared against the specifications. To prevent influences due to measurement tolerances, calibrated systems of the same type are used to measure both prototypes still in development and finished laser systems before shipping or during commissioning or maintenance at the user's site.

When selecting a supplier, Roman Roth – process engineer at Asclepion and the person responsible for the proper and smooth running of manufacturing processes – has several prerequisites: "On the one hand, all our departments need reliable measurement equipment to provide us with accurate and repeatable results. At the same time, our wide range of laser types means that we need many different measurement methods. With MKS, we know that our demands – in terms of both the quality and the diversity of measurement solutions – can be met with standard Ophir sensors or individualized approaches" For example, to measure the power of an Asclepion diode laser, the company uses an MKS thermal sensor, such as the Ophir L50(300)A. The same measuring principle is also applied to solid-state lasers for surgery.

The pulsed solid-state lasers used in dermatology, on the other hand, are measured with pyroelectric sensors. Because of the high power and energy densities involved, Asclepion relies on Ophir sensors of the type PE50BF-DIFH-C, PE50- DIF-ER-C, which have integrated diffusers and thus higher damage thresholds. In order to meet the special requirements of medical technology, the sensors are also adjusted for specific wavelengths, e.g. calibrated to 2940 nm.

Asclepion's collection of metrological solutions for laser power and energy is rounded out with Ophir photodiode sensors. They measure the pilot beam systems that aim at the target in all solid-state lasers, the power of which is in the range of just a few mW. Depending on the area of application, Asclepion transmits the measurement data either via PC interfaces or directly to compact, handheld display devices.

No matter what measurement principle is applied, one thing is certain: Every single laser system that leaves Asclepion's production facility undergoes meticulous final testing. A final inspection protocol – encompassing some 25 to 60 A4 pages – is worked through step by step; depending on the laser system, this last evaluation can take a few days to a week. According to the principle of double checks, every product produced by Asclepion must be formally tested and finally approved by the Quality Assurance Department on the factory site before being shipped out to customers.

Introduced in 2019, the company's picosecond laser proved to be a particular challenge: In addition to the power and/ or energy of the laser beam, the beam profile must also be carefully checked and pre-adjusted on the optical bench during the final test. Here, Asclepion relies on the beam profile measurement taken by an Ophir CCD camera in combination with a beam reducer and the BeamGage or BeamMic analysis software. If, at the end of the beam path, the laser is ever to provide the optimal conditions as prescribed by the laser specifications, it must be carefully pre-adjusted in stages. For this purpose, the beam profile is recorded with the CCD camera at three different positions along the optical bench. These figures show the measurements of a correctly adjusted laser compared to that of a misaligned laser.

Without this camera-based measuring solution, it would be difficult and time-consuming to adjust the resonator on the optical bench. Too much divergence in the beam would lead to unwanted radiation of downstream optical components. Using the CCD camera saves considerable time and effort in this sensitive process while ensuring repeatable measurements of the beam profile. Also in his role as Asclepion's test equipment officer, Roman Roth is very satisfied with the collaboration: "The Ophir measuring devices work reliably and deliver reproducible results – both of which are essential in medical technology. In terms of sustainability, the quality and durability of the measurement technology are beyond reproach; we're still using our Ophir Nova display devices from 1996."

In general, the Ophir measuring instruments are in constant use at Asclepion Laser Technologies. Whether in the development phase of the laser systems, in the final test or during installation and maintenance at the customer: Any deviation from the specification is detected, and potential sources of error are eliminated immediately. In this manner, decoupling mirrors of poor quality or inhomogeneous laser crystals, for example, have been caught and rejected during final testing. Roman Roth is sure of one thing: "No matter which of our lasers it is, it's tested with at least one Ophir instrument." This makes it all the more important to regularly check the more than 100 sensors from Ophir that are currently employed throughout the various areas of Asclepion Laser Technologies. Every year, these instruments are calibrated according to specs in Ophir's European calibration laboratory in Darmstadt. This in turn guarantees the precise measurement of all Asclepion laser systems and thus their enduring quality, for the safety of operators and patients alike.

Additive manufacturing technologies have taken on an important role in serial production, manufacturing light-weight but complex mechanical parts quickly and efficiently.

Serial production – what we also know as mass production assembly lines – relies on a consistently high level of quality. And consistency in manufactured components means that machines using additive technologies must always deliver the same repeatable and reliable results.

Today, we will discover how one of our customers uses Ophir’s BeamWatch AM to make sure that additive technologies deliver the highest quality.

The Fraunhofer Research Institute based in Germany helps companies produce additive-manufactured components which are frequently subjected to heavy loads – for instance, elements that are used in airplanes, cars, trains, and ships.

Component failure in these industries can bring catastrophic results. And for this reason, Fraunhofer created a quality assurance and certification working group that focuses on just one goal: Delivering. Repeatable. Results.

They want to be absolutely sure that additive manufacturing produces a high-quality product over and over and over again.

The key to meeting this goal?
Making sure that the laser parameters are checked regularly. Fraunhofer found that beam sources age over time, and that output power and beam quality suffer from focus shifts or power losses.

To circumvent this kind of wear and tear, Fraunhofer relies on BeamWatch AM for comprehensive measurements - regular beam measurements performed at short intervals which guarantees meticulous quality assurance.

BeamWatch AM is “contact-less” –it images the beam without contact, measuring critical beam parameters in real time as the beam passes through.

Quick. Compact. With no contact.
Experts at Fraunhofer trust BeamWatch AM to make sure that the quality of the laser beam safeguards reproducibility of manufactured parts using additive technologies.

Read more about Fraunhofer’s use of BeamWatch AM on our blog.

Here at Ophir, we often talk about the importance of measuring beam profile accuracy. And today, we have an opportunity to discuss how one of our customers, Messer Cutting Systems, optimized the quality of their laser cut by integrating Ophir’s BeamWatch system into their production line.

Messer Cutting Systems is a global supplier of products and services for the metal processing industry. Employing more than 800 people at its five main production sites, Messer’s portfolio includes oxyacetylene, plasma, and laser-cutting systems ranging from hand-held devices to special machinery for shipbuilding.

Measurement technology plays a particularly decisive role for Messer’s development of new cutting systems.

Previous measurement techniques were very time-consuming for Messer, and that’s when Ophir’s BeamWatch system caught their eye. Messer was interested in time-saving measurement technologies for many types of high-powered lasers with different cutting heads.

Ophir’s BeamWatch has no upper power limitations on the beams it can measure. Measurements taken at video frame rates allow the focus shift to be temporally resolved and displayed in near-real time.

And that is what interested Messer. With the use of BeamWatch, Messer developed an algorithm to minimize the thermal focus shift that was specific to each type of cutting head, allowing them to measure different cutting heads quickly and easily, without incurring additional costs.

The result?
Simple and fast measuring that optimized the quality of the laser cut. For Messer, Ophir’s BeamWatch technology is ideal. It’s lightweight, compact, easy to transport and easy to operate, without worrying about power limitations.

For more details about the Messer Cutting System’s case study, read in the link below And contact us to see how you can integrate BeamWatch technology into your operation.

Körber Business Area Technologies develops tailor-made systems for the luxury food and tobacco industries.

Production lines for these industries are often complex.

They process a large volume of items within a given time frame, and they tend to run 24/7.

Measuring laser power during production itself is critical for maintaining product quality.

Korber’s production equipment contains laser-based perforation systems which are used to create holes in filters.

The functionality and accuracy of these laser-based systems require incorporation of power gauges within the production line and seamless monitoring during the manufacturing process.

Working in tandem with Korber, Ophir developed two OEM sensors, which were customized to Korber’s exact requirements.

The first is a power-measuring sensor, which is integrated into the production line equipment,
or can be retro-fitted if need be. It continuously monitors and displays the average power on a nearby screen. In case of a reduction in laser power, there is more than enough time to correct the problem and prevent damaged products.

The second sensor we developed is a quad sensor, which measures the power and position of the laser beam.

This measurement is done during routine maintenance to check the overall settings of the laser unit. Also, in case of any abnormalities found in the production process, the laser unit can quickly and easily be tested to see if it needs adjustment.

The sensors we developed for Korber are so robust and reliable that they are used in Korber’s own R&D lab.

To read more about our work with Korber, check out our blog.

The positive effects of red and infrared light on healing have been studied for a long time.

The technical term is “photobiomodulation,” a non-invasive therapeutic approach using low-intensity light to stimulate biological processes in the body, triggering a cascade of biochemical reactions at the cellular level that can help you heal.

Studies since the 1960s have shown that light from LEDs in the 630-850 nm wavelengths has a particularly positive effect on humans.

The Lichtblock Uno, developed by Daniel Sentker, is a red-light lamp consisting of outer and inner LED arrays, that can be used in a variety of modes.

Measuring the parameters of the device, critical to its correct and consistent performance and quality, turned out to be an unexpected challenge.
Most suppliers of red-light lamps use simple solar meters which are usually inaccurate and often result in non-repeatable results, making them essentially useless for Lichtblock’s purpose.

Lichtblock was looking for a reliable and repeatable measurement method for light intensity, or more precisely, power incident per unit area on a surface.

They found the answer in Ophir’s 2A-BB-9 sensor, combined with Ophir’s StarLite meter (or display).

When the LED light falls on the sensor's surface, the heat flow generated inside the sensor by the absorption of the light is proportional to the power in the beam.

Combining that measured power with the size of the irradiated surface, as long as the measurement is always taken at exactly the same distance from the Lichtblock, results in accurate, repeatable, and reliable measurements. The Lichtblock team use this setup for incoming inspection of the externally-manufactured LEDs, quality control testing of the finished product, and even for comparison with competing products.

And the result? A product that does what it promises to do. And happy customers.

Read more about the Lichtblock Uno, and the sensors provided by Ophir, on our blog.

Battery modules are the beating heart of every electric car. And no one knows this better than the BMW Group, which launched the first fully electric car in 2013.

Laser welding in the production of battery cells requires absolute precision.More than 15,000 spot welds per hour are performed in each system and the quality of the battery modules depends on the consistently high quality of the laser beam parameters.

Precision means proactively and regularly checking the laser beam’s key parameters before the welding process begins. But without disrupting the production cycle.

Ophir’s BeamWatch Integrated system was the answer.
Specifically developed for the automotive industry, BeamWatch Integrated offers fast and non-contact measurements of a laser’s focus position and shift, as well as power.

BeamWatch is able to detect a thermal focus shift, and once this factor is known, adjustments can made in the manufacturing process so that consistent weld depth is attainable.

Contact welding is negatively impacted by spatters on a laser’s protective glass, which affects focus shift and diameter - and that can cause a shallow weld seam.

When integrating BeamWatch into the production process, a defocused laser beam caused by smudged glass is more easily detectable so that shallow seams are pre-empted.

Thanks to Ophir’s BeamWatch Integrated systems, BMW is able to check the laser beams before manufacturing each new battery module. The laser is briefly operated at full power to determine focus shift, and only after the parameters are confirmed does the welding process begin.

If a deviation in a parameter is detected, a warning message is displayed so that an operator can proactively check the protective glass, preventing errors before welding starts.

Today, Ophir’s BeamWatch Integrated System is built into all the automated production lines where BMW’s 5th-generation battery modules are made.

You can read more about our work with BMW on our blog.