STM Optoelectronics

Due to this focus, our optical sensors easily distinguish themselves from products of other manufacturers in terms of numerous technical properties:

- With our own unique microoptical components we achieve an unsurpassed ratio of size to range. With photoelectric sensors in miniature sizes from 2 mm (approx. 0.08”) to 8 mm (approx. 0.3”), for example, we even beat specialists in the high-power range.

- We make optical sensors vacuum-capable. For pressures down to 10-9  mbar. With selected materials and adapted designs.

- We offer the only technological alternative to fiber optics. And what an alternative! Our MICROmote sensor family is uncompromisingly optimized with the smallest installation volume. Integrated microoptical components provide high ranges and outstanding resolutions. A metal housing provides the necessary robustness. Highly flexible electrical wires transmit the sensor signals to separate amplifiers with comfortable display and user control elements, which are then installed outside of the “hot spots,” i.e., where space doesn’t play a decisive role.

- Our COMPACT optical sensor product family combines small dimensions with compact electronics. Powerful miniature optical components and a metal housing are their characteristic features. Due to their optical precision and the flexibility of our modular concept, they can be found in the most interesting customized models in the systems of many renowned machine manufacturers.

- Standard products such as fork sensors are important elements in our product range. Here, too, we, as manufacturers, are technically strong and competitive. What makes us different from our competitors is this: With us, there are also precision models or modular size intervals that perfectly fit customer needs. And we can handle special dimensions and special materials.

- Our frame sensors for detection and counting of unordered falling objects with dynamic or static function are much more precise and flexible than comparable products usually are. With a modular size system, we cover the entire range of window sizes from 40 x 40 mm (approx. 1.6” x 1.6”) to 400 x 400 mm (approx. 15.7” x 15.7”).

Curious? You can find additional interesting details in the sections Technology and Products.

With us, development and manufacturing of an optical sensor begins with the semiconductor chip. For transmitter elements (LEDs), for example, one of these chips is currently around 200 microns in size. Some 50,000 of these chips can fit on a 5-inch wafer. Still, we would like to reduce the size even more to achieve ideal conditions for optical imaging.

Handling these tiny parts understandably places high demands on the machines and their operators. The chip and wire bonding technologies commonly used today are included in our standard know-how. When it comes to accuracy of positioning, we simply have to be a little bit better than other LED manufacturers are.



We need to be so that we can achieve the precision demanded of our microoptical components that make up our sensors. Only correspondingly precise coordination of mechanical and optical designs leads to precise forming of the emitting light beam, which in turn is an indispensable requirement for a precision optical sensor application. Our products bearing the microSPOT and nanoSPOT trademarks are currently the best that can be made with LED-based miniature optical sensors.

We combine these components with electronic component assemblies and suitable housings to form end products in a perfected modular system. This provides us with the greatest possible flexibility in assembly. We are capable of one-piece-workflow manufacturing largely independently of lot size.

In connection with our application know-how, we are hence the ideal suppliers both for small quantities of customized parts and for large volumes of mass-produced products.

We think that a sensor, complete with its peripherals, should be adapted to a machine or a system, not vice versa.

Compared with the early years of automation, today optical sensors have a high degree of “intelligent” analysis, thanks to modern microelectronics, which allows them to be able to deal independently with a large variety of application and operating conditions at the push of a button.

Most sensor applications, however, are usually a little more complicated than they first appear to be or than they are assumed to be in the development phase for many a system. In reality, they are all different! Numerous relationships that can prove to be sticking points in later operation in borderline situations can only be detected and fully understood through precise optical and electronic analysis in the lab.




Thus, only carefully designed solutions function optimally and reliably. To be able to exhaust the performance potential, it definitely makes sense to adapt sensors specifically to requirements.

OK, special solutions also conceal risks for the user, and of course a cost-sensitive designer values standardization more than anything else for realizing functions as cheaply as possible. But reasonable compromises can also be made. We see this as our task.

Sensors are and will remain key to the performance capabilities of an automated system. If optical sensors are the eyes of an intelligent machine, you shouldn’t save on the optical components.

STM Sensor Technology Munich GmbH was founded in 1989 by Dipl.-Ing. Edgar Melzner and Prof. Dr.-Ing. H.-D. Ließ with the goal of advancing the results of university research projects to create commercially viable products.



Right from the start, STM focused completely on miniaturization technologies for optical sensors. Through an innovative spirit and work beyond the well-worn development paths, an individual technological approach arose, leading over the years to today’s range of high-performance optical sensors.

Apart from the miniaturization of optoelectronic components, further core areas of expertise were formed: One example is application of optical sensors in a high vacuum environment, a field in which STM is a leader today.

Today STM is a group of companies with a clear division of tasks:

STM Sensor Technologie München GmbH manufactures products for internal use as well as for external clients at its Neubiberg (near Munich, Germany) location, using the modern technologies created through in-house research and development. More and more renowned sensor manufacturers are relying on our technology through our components, component assemblies, and complete products.



STM Sensors Inc. in Toledo, Ohio, and Dallas, Texas, and 35 sales partners worldwide sell our products and services in international markets for automation technology.

STM Applied Development secures the necessary progress in R&D with a continued strong link to our university roots as well as with innovative strength and engineering know-how.

Despite this clear division of tasks, STM sees itself as a single unit that stands for high-performance standard products, competent consulting, and powerful customized solutions.