- OCF fiber optic amplifier
- Technology
OCF fiber optic amplifier: Technology
Fiber optic sensors are a common form of photoelectric sensing in the manufacturing industry. Their flexibility to reliably detect small targets in small spaces on a machine is unmatched. Understanding how the technology works will help you choose the right product for your industrial automation application.
A fiber optic sensor consists of two main parts: an electrical amplifier and a mechanical fiber optic cable.
- The amplifier contains the sensing intelligence. It processes the received light signal, controls switching behavior, and provides application performance data and diagnostics, often communicated via IO-Link.
- The fiber optic cable delivers light to the target object for detection. Because the cable contains no electronics, it can be installed in high-temperature, hazardous, or hard-to-access environments where traditional sensors are impractical. The separation of the electrical and mechanical components also allows greater flexibility in system design.
Fiber optic cables must be properly routed to maintain optimal performance. Excessive bending can reduce light transmission by causing the optical signal to refract and escape through the cladding. For demanding applications, high-flex fiber options are available, allowing for extremely small bending radii while maintaining reliable light transmission.
Optical fiber is comprised of a central core with a high refractive index surrounded by cladding with a low refractive index. When light enters the core, it travels down the path of the fiber by bouncing at a shallow angle.
Through beam sensor
The transmitter and receiver are integrated in different fiber-optic heads and mounted opposite of eachother. Light is sent from the transmitter lens and is picked up by the receiver lens. The objects are detected by interruption of the light beam. As long as the target is large and solid enough to break the effective beam, the color, shape, angle, reflectivity and surface finish will not affect the application. This makes them more reliable than diffuse sensors, which depend on light reflecting off the target.
Diffuse sensor
The transmitter and receiver are integrated in the same sensing head. The transmitted light reflects back to the sensor from the target and the receiver evaluates it. It is important to carefully consider the characteristics of the target and the background behind the target when selecting the correct solution for an application. Diffuse sensors have less excess gain than thru-beam pairs but are easier to mount because there is only one fiber head.
Fiber arrangements for diffuse sensors
Standard glass fiber:
Flexible multifiber bundles.
Standard plastic fiber:
Two fibers, 0.5 or 1 mm thick.
Asymmetrical fiber:
High accuracy plastic fibers.
Interspersed fiber:
High flex plastic fibers.
Fiber array:
Plastic fibers to detect small objects.