Precise, fast and flexible – Optical metrology at LASER World of PHOTONICS 2013

Optical measuring and testing techniques have become indispensible in industry, the skilled trades, medicine, medical technology and science. They deliver ultra-precise measuring results. They are quick, non-invasive and flexible. The latest trends and applications will be on display at LASER World of PHOTONICS, the International Trade Fair for Optical Technologies, from May 13 – 16, 2013 and at the World of Photonics Congress 2013, which takes place at Messe München at the same time as the fair.

 

Among other things, the industry outlook for machine vision, which is part of the sector for optical measuring and testing techniques, underscores the significance of optical techniques for measuring tasks. According to the VDMA Machine Vision Group, the industry in Germany is expected to repeat its 2011 sales record of 1.5 billion euros again in 2012. Despite the uncertain economic setting, it is forecasting another increase of two percent for 2013. The European Machine Vision Association (EMVA) is similarly confident: According to a flash survey of EMVA members, 56 percent expect their companies to grow at a rate of more than five percent in 2013. And a good 13 percent expect growth to be as much as five percent.

 

Hot topics in 2013: More exact testing, saving energy, faster production and miniaturization

One of the trends in optical metrology that LASER World of PHOTONICS 2013 will focus on is the growing use of fiber-optic sensors. For the most part, the increase can be attributed to fiber-optic sensing tools for making distributed measurements of temperature and strain, as the Karlsruhe-based company Polytec explains. The principle: Light is conducted through glass fibers no thicker than a human hair, and it is altered by stretching the fiber or subjecting it to temperature change. This makes it possible to determine the type of influence and its location. The latest development in this technology is share sensing, which is known as the “intelligent needle” in medicine. In this case, three glass fibers are imbedded along the longitudinal axis of a needle. This makes it possible to register every contraction or elongation of the needle three dimensionally and to determine the exact position of the needle’s tip. The technique is extremely precise, which is particularly useful in minimally invasive procedures. This approach also opens up new possibilities when it comes to demanding positioning tasks in robotics, oceanography, aviation and aerospace.

 

Other improved testing techniques make it possible to manufacture object lenses for the widest variety of tasks more quickly, easily and with increased quality. Trioptics, for example, has new systems that can determine the 3D positions of all optical surfaces in mounted lens systems. They can be used for quality assurance by measuring finished systems, from the smallest endoscope lenses to lenses for semiconductor manufacturing that weigh several hundred kilograms. However, these systems can also be used to perfectly center lenses in manufacturing. Trioptics has also managed to extend this type of quality testing to infrared object lenses. Optical measuring systems can be used to characterize infrared lenses and object lenses. Depending on the system, they are used to measure focal length, flange focal length, centering errors, surface topography or MTF. The higher quality of the infrared object lenses benefits assistance systems and monitoring cameras in security technology, for example.

 

To take complete advantage of the high precision and speed of optical measuring techniques, positioning technology that is just as precise is an absolute must. “The demands being made of optical measuring technology are moving toward higher precision and compact designs. High dynamics play an important role when it comes to throughput rates in industrial applications,” explains Steffen Arnold, Head of the Market & Products Department at Physik Instrumente in Karlsruhe, a company that specializes in positioning solutions. According to Arnold, piezoelectric positioning and drive solutions are gaining ground. They are compact, fast and precise. Another increasingly important advantage is that they do not use any energy when a position is only being maintained. This aspect of saving energy is particularly beneficial in mobile solutions and when dealing with widely distributed measuring locations that are battery powered.

 

Another optical approach that is being used in a growing number of applications is spectral analysis. That is because these systems are increasingly efficient and more compact. According to the experts at Polytec, the trend here is toward increased system mobility. Raman spectrometers, for example, are now available as handheld devices that perform just as well as conventional laboratory spectrometers. As a result, mobile applications in quality assurance or in the production process are also possible. This also means that enormous increases in efficiency are possible when monitoring solid, liquid or powder raw materials and products. Pioneering industries include the chemical, pharma and food industries.

 

Hyperspectral imaging is finding new applications in the food industry as well as in other branches of industry. This image-generating form of spectroscopy uses digital camera systems to measure a wavelength range that is far above that of visible light. While the human eye only registers the range between approximately 0.4 and 0.7 micrometers, hyperspectral cameras register values less than 0.1 micrometers in the ultraviolet range and more than 10 micrometers in the infrared range. As a result, they can be used to monitor fruit and meat products or to inspect agricultural land from the air. In the United States, hyperspectral imaging is one of the standard techniques used in the mandatory inspection of poultry.

 

From the research perspective: International Metrology Conference

Optical measuring techniques will also play an important role at the World of Photonics Congress, which takes place at the neighboring ICM – International Congress Center München from May 12 – 16, 2013. The congress includes an entire conferences dedicated to the topic of optical metrology. The Optical Metrology Conference is organized by SPIE Europe, the European section of the International Society for Optical Engineering. From May 13 – 16, 2013, users and scientists will meet in Munich to discuss the latest findings and applications in the sectors for optical metrology, videometrics and machine vision. Some new topics have also been added to the conference agenda: For example, for the first time ever, the conference will deal with optical methods for the inspection, characterization and imaging of biomaterials and examine techniques for automated visual inspection. A detailed agenda will be available online in the spring of 2013.

 

• “CLEO/Europe-EQEC”, organized by the European Physical Society (EPS), sponsored by the EPS Quantum Electronics and Optics Division, OSA, IEEE/LEOS
• “Optofluidics”, “Manufacturing of Optical Components” and “Advanced Optomechanical “Engineering, organized by the European Optical Society (EOS)
• “LiM - Lasers in Manufacturing”, organized by the Scientific Laser Society (WLT);
• “ECBO - European Conference on Biomedical Optics“, organized by the Optical Society of America (OSA) and the International Society for Optics and Photonics (SPIE)
• Optical Metrology, organized by SPIE Europe