Explore the comprehensive Interferometric Measurements Product Details featuring advanced sensor technologies for precise, non-contact thickness and distance measurements. Learn about innovative interferometric and optical coherence tomography systems designed for high-speed, accurate industrial applications. Benefit from insights into patented methods and cutting-edge products that enhance quality assurance and laser processing across diverse material types and manufacturing processes.

Precitec GmbH & Co. KG

Product Details

Founded: 1971 | Headquarters: Germany & Switzerland | CEO: Dr. Thilo Wersborg (2010 – ) | Website: https://www.precitec.com

• The CHRocodile 2 IT interferometric sensor enables ultra-fast and highly precise measurements of all infrared-transparent industrial materials. With an unrivalled speed of 70 kHz measurements per second, the CHRocodile 2 IT sensor is ideal for one-sided, non-contact distance and thickness measurement of non-transparent materials.
• The CHRocodile 2 K optical sensor uses infrared light to carry out highly precise, non-contact measurements of the wall thickness of non-transparent or opaque plastics. The Interferometric measuring range of CHRocodile 2 K is 15 µm - 1500 µm. The sensor has ultra-high dynamic response and outstanding signal-to-noise ratio ensure precise measuring results in a wide distance tolerance range. 
• Precitec's Flying Spot Scanner (FSS) enables high-speed OCT imaging for thickness and topography, and is combinable with various CHRocodile 2 IT sensors to create a smart inspection system. The FSS features pioneering one-of-its-kind technology enabling high-speed non-contact area inspection for inline and offline quality assurance and 3D measurement on a wide range of materials and surfaces.
• The CHRocodile 2S/2SE/2S HS carries out optical thickness measurement and optical distance measurement at high speeds and with optimal precision. Reflecting or dispersive, opaque or transparent, rough or polished – whatever the surface, the non-contact CHRocodile 2S/2SE/2S HS sensor delivers the optical thickness measurement or optical distance measurement for a variety of industrial applications.

Prominent Patents

US11079218B2 discloses about measuring a keyhole depth as well as topography of a workpiece by using interferometric measurement. The topography measurement is used  for regulating process input variables. The process input variables can be  a processing speed, a laser power, a laser focus, and operating parameters of the laser processing head.

DE102022120069A1 discloses about a faster and more accurate measurement of multiple points on a workpiece using principle of optical coherence tomography. The invention enables using a polychromatic light source and a spectrograph detector enables efficient and precise distance calculations & thickness measurement of multiple points on a workpiece. Further, the inclusion of a scanning device enhances the device's capability to measure over larger areas in a short amount of time, thereby making it a versatile and efficient tool for distance measurements of various points on a work piece.

US11090760B2 discloses about a method for measuring and controlling a distance or a focal position of a machining head or laser beam during laser machining processes, such as cutting, welding, drilling, or machining. A measurement light beam is focused on a workpiece surface by a focusing lens and reflected back, where it is superimposed with the reflected reference light beam. This approach allows for highly dynamic and precise adjustment of the distance between the machining head and the workpiece, regardless of the material or process conditions.  Further, determined distance is compared with nominal distance and a control signal is fed to a control circuit which is designed for initiating the  displacement of the machining head in the direction of a processing beam.

US2024075550A1 discloses about a laser processing head for material processing with lasers, specifically for processing workpieces by means of a laser beam. The laser processing head includes a sensor arrangement for process monitoring and controlling. The sensor arrangement comprises  an OCT sensor for distance measurement. Further, a control unit is connected to a signal output of the sensor arrangement in order to control the focal position of the laser beam to monitor the laser machining process.

US9770783B2 discloses about an interferometric measuring device which is used to deduce depth information and the measured depth information is then fed to a control unit by a feedback control loop where the control unit further controls the positioning drive of the focus optics based on the depth information. 

Lessmüller Lasertechnik GmbH

Product Details

Founded: 1990 | Headquarters: Germany | CEO: Eckhard Lessmüller  (1990 – ) | Website: https://lessmueller.de/?lang=en

• The OCT 250 system from Lessmüller Lasertechnik offers completely new possibilities for the quality assurance of your welding process. Coaxially coupled into the laser beam of the process optics or as a standalone variant, the OCT performs a highly accurate height profile measurement. This means that a single system can be used for precise seam tracking and contour/surface inspection of the finished seam without increasing cycle-time. There also is no other method to measure the weld depth during the process in a more economical way.
• The OCTSCAN 2.5 from Lessmüller Lasertechnik is the perfect combination of process optics with scanner technology and OCT system. The system allows very high welding speeds during the remote welding of electrical and electronic components, such as battery cells and bus bars. OCTSCAN 2.5 masters the high requirements for extremely fast and precise repositioning of the laser beam due to the seamless optical and electronic integration of optics and OCT. The additional possibilities of weld depth measurement and topography inspection make the OCT system the ideal tool for demanding applications.

Prominent Patents

US2024149456A1 discloses about an optical coherence tomography (OCT) based measuring method. The OCT performs measurements at several measuring position lying on a geometric measurement for example, a first geometric measurement is a first measurement line that scans the edge  or the workpiece in general ,and a second geometric measurement is a second measurement line that scans a weld seam formed when machining the workpiece. Further, the workpiece specific position information is transmitted to a robot control system via an interface. The transfer of the position information enables the robot control system to control the positioning of the machining head or the positioning of the sample beam.

DE102016008184B4 discloses about a measuring device for monitoring a machining process and provides comprehensive quality assurance and control during the machining of a workpiece. By utilizing an optical coherence tomograph, the device allows for simultaneous monitoring of the machining process while performing position measurements on the workpiece. The accurate measurement information at each measuring point on the workpiece includes the topographic details & detection of height differences along the optical measuring beam axis in the micrometer range.

DE102016001661B3 discloses about using an optical coherence tomograph (OCT) with a measuring beam source to displace the measuring beam on the workpiece for position measurements. By generating an OCT measuring beam, height differences along the measuring beam axis on the workpiece can be detected. Further, an optical coherence tomograph is used to measure relative inclination of the processing beam with respect to a reference direction of the processing beam and further adjusting the position of the beam depending on the determined relative inclination of the surface portion.

US2024149374A1 discloses about an optical coherence tomography (OCT) for measurements along a weld seam. By dynamically adjusting the leading and trailing beams of the sample beam during machining, the device can track the seam from the initial portion to the end portion, even in areas with limited accessibility. This unique approach allows for precise measurements of the workpiece and weld seam, enhancing the overall welding process. Further, on the basis of workpiece-specific position information from acquired measurement data, real-time position control for the machining head is performed.

DE102021122438B3 discloses about a measuring device by means of which optical coherence tomography measurements is carried out during the machining of a workpiece. The optical coherence tomography is carried out for determining a height profile and a depth profile of a section of the workpiece to be machined.

Laser Mechanisms, Inc.

Product Details

Founded: 1980 | Headquarters: USA | CEO: William Fredrick (1980 – ) | Website: https://www.lasermech.com

Laser Mechanisms has designed the LDD system seamlessly into all of its FiberWELD® heads and it can also be integrated into Laser Mech® CO2 beam delivery systems.

Laser Depth Dynamics’ (LDD) patented imaging technique is the only technology that delivers direct, geometric measurements of laser weld penetration – during the weld. Inline Coherent Imaging, or ICI, uses a low-power IR laser beam to gauge distances and the extra distance from the material surface to the bottom of the keyhole is the weld penetration. This measurement beam is directed through the same optics as the welding beam, getting focused right to the bottom of the keyhole’s vapor channel and returning the actual penetration in real time. The resulting data is equivalent to a lengthwise section of the weld, delivered instantly, with no additional labor and without destroying the part. No more destructive testing and weld quality data saved for each weld produced.

Whitepapers/ Research Papers

• The research  paper “Interferometric surface inspection with movable measurement spot: high-speed OCT imaging for thickness and topography in industry”  discloses that for complex and time sensitive measurement tasks, Precitec Optronik has developed the Flying Spot Sensor. The active measuring head of sensor is specially developed for in-line use and ideally complements the spectral interferometric sensor to form a smart inspection system. The light from the sensor is coupled into the measuring head via a light guide and deflected by a mirror system, a so-called galvanometer scanner. By using specialize focusing modules, the Flying Spot Scanner can be adapted to different application scenarios. The measurement system is  used in two operating modes, a thickness mode, or a distance mode. The two operating modes can be selected at will via the digital interface, which means that the switching process can be easily integrated into an automatic measuring sequence.
• The research paper “Low coherence interferometry in selective laser melting” by Precitec Optronik discloses a novel sensor concept based on the low coherence interferometry (LCI) which is  integrated into an SLM production setup. The sensor is mounted coaxially to the processing laser beam and is capable of sampling distances along the optical axis. The optical sensor is based on the PRECITEC IDM sensor (www.precitec.de). The sensor concept has the potential to detect the defects during the production for every single layer. The maximum scan rate of the device is 70 kHz and complies with the requirements in SLM (selective laser melting). Further, the reference discloses the applications of LCI based sensors in SLM: 1) Determination of the focus position 2) Detect powder surface 3) remove excessive powder material 4) Inspection of core regions 5) Inspection of contour regions 6) Monitoring of the melt pool etc.
• The research paper “OCT sensor for layer height control in DED using SIEMENS machine controller” by  Precitec Optronik discloses the Sensors based on OCT (optical coherence tomography)/ low coherence interferometry. An interferometer with a light source of low coherence length is used to measure distances and the composition of human tissue, e.g. the cornea. The short coherence length is achieved using light sources that emit broad spectrum light. The applied light sources are typically super luminescent diodes (SLDs) with a range of some 10 nanometers, or a Swept Source Laser. The sensor is used to determine the thickness and distance sensor based on spectral domain OCT and this is adapted to material processing applications with laser sources of high beam quality. The adapted technology allowed distance measurement to the required accuracy of about 10 microns, even over long distances.
• The research paper “The Next Level – Controlled Conformal Coating Processes” by Precitec Optronik discloses the Optical sensor technology for absolute thickness measurement. The sensors of the CHRocodile product line, developed and manufactured by Precitec Optronik, are designed to allow contact-free, fast and precise distance measurements on and thickness measurements of various materials. Due to its small dimensions the absolute thickness measurement of coatings, films or wafers is based on the interferometric measurement principle.
• The research paper “OCT produces a better weld“ by lessmuller Lasertechnik GmbH discloses the Laser welding using optical coherence tomography (OCT) . OCT brings laser welding to its proper target, ensuring high-quality welds and enabling the reduction of cycle times during welding along sophisticated trajectories or during positioning at challenging joints or low-dimensional e-mobility elements. OCT is beneficial for online omnidirectional seam tracking exact nondestructive measurement of keyhole depth, and identification of faults and defects at the resulting seam. Automotive companies are now increasingly using OCT in their manufacturing processes.  
• The research paper “Implementing OCT for industrial weld monitoring: Dr Nataliya Deyneka-Dupriez, of Lessmuller Lasertechnik, describes the benefits that OCT can bring to weld monitoring, and highlights how the technology is starting to find applications in e-mobility” by lessmuller Lasertechnik GmbH discloses the Optical coherence tomography (OCT) technology  which is capable of obtaining depth images with micrometer-scale resolution by measuring and processing the interference of light being scattered from a particular point. By using OCT scanners, not only in-process weld monitoring, but also non-contact seam tracking and non-destructive real-time quality control of welds can be achieved with a precision and reliability unobtainable through conventional process monitoring. Further, the reference discloses the additional benefits of using OCT over alternative monitoring techniques, for example laser triangulation, include its ability to operate under a coaxial measurement configuration and perform omnidirectional tracking.

Disclaimer

This report has been prepared by Effectual Services engineer(s) and contains analysis and recommendations based on the understanding of the subject matter by the searcher. The searcher’s analysis and recommendations are purely technical suggestions and should not be construed as legal opinions under any circumstances. Client alone reserves the right to make a final decision on the subject matter as disclosed. Further, our search methodology includes steps and protocols aimed at a good faith effort to produce a reasonably complete and accurate search report, but such methodology is not without limitation. Searching, by its nature, relies at least in part on the subjective assessment of individual searchers. Further, Effectual Services may have used one or more third-party databases while preparing this report, and cannot warrant the accuracy of the information obtained from third-party databases. Effectual Services is not responsible for maintaining the accuracy or inclusiveness of these databases, which may be incomplete or contain errors. Such databases may also include translations, and Effectual Services cannot warrant the accuracy/authenticity of such translations. Due to the very nature of searching, we cannot guarantee that a search is free of any error or omission, and thus, WE DISCLAIM ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

This report is technical in nature, and contains no legal opinion. The characterization, paraphrasing, quotation, inclusion or omission of any references with regard to this report represents the personal, non-legal judgment of the one or more technical researchers involved in the preparation of this report. Therefore, no content of this report, including the characterization, paraphrasing, quotation, inclusion or omission of any references, should be construed as having any legal weight or being legally dispositive in any manner. This report is provided without any express or implied warranties, including fitness for a particular purpose such as patentability, infringement, freedom-to-operate or invalidity opinion. Effectual Services cannot be held responsible for any damages whether direct or consequential, based on use of this report.