Fiber Optic Sensing Technology: What It Is and How It Works
November 1, 2017
This article explains what fiber optics are and how they work for photoelectric sensing in industrial applications. Keep reading to learn important terminology and the basics of fiber optic systems and assemblies.
Types of Fibers
How a Fiber Optic System Works
How fiber optics transport light rays can be explained with the optical principle of total internal reflection. This principle states that any ray of light hitting the boundary between the core and the cladding (which have different densities) will be totally reflected, provided that the angle of incidence is less than a certain critical value. The light beam is transported all the way through the tiny fiber by reflection, exiting at the same approximate angle as it entered the fiber.
Fiber Optic Assemblies
A fiber optic assembly determines the sensing mode. So, once you have chosen the type of fiber you want to use, you would then choose what assembly your application requires.
Individual Fiber Optic Assemblies
Individual fiber optics assemblies simply guide light from an emitter to a sensing location, or from the sensing location back to a receiver. The configuration of the fiber optic assembly determines the sensing mode. Individual assemblies are usually used in pairs for opposed-mode sensing.
Bifurcated Fiber Optic Assemblies
Bifurcated fiber optics conduct the emitted light together with the received light (via two branches consisting of different fibers) within one fiber optic assembly. This allows a single sensor to both illuminate and view an object through the same fiber optic assembly.
If an object appears in front of the sensing end of a bifurcated fiber optic, light from one branch will be reflected off the object and back to the receiver through the other branch. Bifurcated assemblies are typically used in diffuse mode sensing and can also be used in retroreflective-mode sensing.
For More Information
For more information about fiber optic sensing, contact an expert to discuss your specific applciation.
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