Fiber Optic Technology

SCHOTT has been a leading manufacturer of fiber optics for over 60 years, playing a key role in lighting and imaging. Whether guiding light and images around a corner, out of a tight space, or away from a hot, dark, or equally challenging area, fiber optics are central to the world’s most advanced technologies.

What are optical glass fibers?

At the heart of all fiber optic technology is the glass fiber. This thin, flexible, and transparent material has a diameter about the size of a human hair. Light travels through the core of optical fibers, emitting light or forming images at the fiber bundle’s end.

This transmission is possible thanks to two materials with different refractive indices. Glass fibers are composed of a high refractive index core and a low refractive index cladding. The principle of total internal reflection (TIR) dictates that when light hits the boundary between the core and the cladding below the limiting angle, it’s reflected and carried further along the fiber to the end.

Illustration of how a glass optical fiber light guide transfers light

Light Guides

Light guides carry light from one end to the other. The arrangement of the SCHOTT fibers can be randomized to create homogenous lighting.

Illustration of how a glass optical fiber image guide transfers an image of a sail boat

Image Guides

Image guides are able to transport images over a long distance and magnify, reduce or invert them. Each fiber within the image guide corresponds to a single image pixel, which makes the arrangement of the fibers critical.

Purpose and function

Glass optical fibers are able to transmit light and images over long distances, through tight spaces, and from inhospitable situations. This capability has a vast range of uses, from examination in the healthcare sector to illumination in the aviation industry.

Glass fibers are unaffected by a range of environmental factors, such as high or low temperature, with no risk of electrical interference. This enables them to be used directly in challenging environments – for instance, decoupling electronic devices such as light sources, sensors or cameras from the actual area of application.
A SCHOTT employee with several glass optical fibers during the production process

Types of glass optical fiber

Glass optical fibers can be divided into flexible and rigid guides. Flexible light or image guides are often longer than rigid guides and normally used when the target lies around a corner or in a narrow space. This demands a high level of flexibility and movement.

Rigid light or image guides are made up of bundles of fused fibers. Typical lighting applications include light guides for dentistry equipment or rigid endoscopes. For imaging applications, they are used to make a wide range of tapers and faceplates, which can transmit magnified, reduced or inverted images from an input surface to an output surface. Hybrid variants are also available.
Array of light and image guides based on glass optical fibers

How optical fiber guides are produced

Not only does SCHOTT manufacture most of the preform blanks required to make glass fibers, it also has its own fiber drawing and winding facilities. This allows us to react to specific customer requirements in a very quick and flexible way.
Fiber drawing
Fiber drawing

SCHOTT’s multi-fiber drawing equipment is loaded with suspended glass rods, which are heated at the lower end to fuse the core and the cladding glass. This creates a single glass fiber for each system. The fibers are then drawn downwards, with the speed of the draw determining the fiber’s diameter. For image conductors, the process is repeated multiple times, with several fibers collected and drawn together in a multi-draw process.
Precision bundling and extrusion
Precision bundling and extrusion

a) Precision bundling

Several primary bundles are gathered to form a final fiber bundle, with the fiber arrangement within flexible bundles usually arbitrary. For certain applications it may be necessary to arrange the fibers in a randomized pattern (light guide) or specific pattern (image guide).

b) Extrusion

The final fiber bundle has the option to be sheathed with polymer in an extrusion line to form a cable. In subsequent assembly processes, fiber bundles and cables are cut to length according to customer requirements and fitted with end sleeves.

End termination
End termination

Depending on the application, a special a) gluing or b) fusing process is used to fix the bundles in the sleeves. During hot fusing, the ends of the fiber bundle are softened and squeezed together under heat and pressure, which eliminates the spaces between individual fibers and reduces the bundle’s diameter. This increases the amount of individual fibers, giving the bundles extra-high transmission and a very dense surface. Since no organic adhesive is required, the bundles can withstand very high temperatures.
Redrawing and reshaping Redrawing and reshaping Redrawing and reshaping Redrawing and reshaping
  • Redrawing and reshaping
  • Redrawing and reshaping
  • Redrawing and reshaping
  • Redrawing and reshaping
Redrawing and reshaping

Multicore rods made from numerous fibers can be stretched into conical shapes or bent or twisted into custom forms. This is especially relevant for rigid guides made into rods, cones, tapers or inverters.
Grinding and polishing
Grinding and polishing

To ensure the best possible light transmission, both ends of the fiber bundle are ground and polished to optical grade quality. While our standard option is polishing perpendicular to the optical axis, curve polishing is also available for special applications such as faceplates.
Quality inspection
Quality inspection

SCHOTT ensures consistent and reliable product quality to meet defined requirements. Standard measurements include optical performance measurements according to DIN 58141 Part 1, Part 2 and Part 3, as well as customized optical measurements depending on specific applications.

Karen Holst, Senior Product Manager for Medical at SCHOTT Lighting and Imaging
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We are certified

SCHOTT strictly adheres to tight regulatory directives and holds a number of quality assurance certificates, including ISO-13485, 50001, and 9001/14001, as well as ASD9100D and MIL-STAN-810G.

SCHOTT: Your reliable supplier for fiber optic products

Over the past 60 years, SCHOTT has been developing and supplying the highest-quality optical fiber products for both mass market and specialty applications for sectors including:

  • Medical
  • Industry
  • Microscopy
  • Aviation
  • Automotive
  • Defense

Want to know more? Let’s talk

Whether you need more information, samples, a quote, or advice for a project, we would be delighted to talk to you.

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Man in glasses in business office on phone while working on laptop