Plastic Optical Fiber (POF): Advantages and Disadvantages

This page explores the pros and cons of Plastic Optical Fiber (POF).

What is Plastic Fiber?

Introduction:

• Plastic Optical Fiber (POF) is an optical fiber where both the core and cladding are made of plastic or polymeric materials. It’s also known as “all plastic fiber.”
• These fibers are typically manufactured using a simple liquid phase double crucible method.

• Using Polystyrene (PS) as the core material (refractive index ≈ 1.59) and Polymethyl methacrylate (PMMA) as the cladding material (refractive index ≈ 1.49) yields excellent results for plastic fiber. PMMA offers better mechanical properties and high resistance to degradation or chemical attack. PS offers relatively less absorption loss compared to other polymeric materials.
• Figure 1 (above) illustrates the basic structure of a plastic fiber.
• All-plastic fibers are best suited for short distances (< 100 meters) and low signal transmission (~ few Mbps) systems. They also find applications as all-plastic strain sensors and acoustic sensors. They are primarily used in the medical and automotive industries.

Benefits or Advantages of Plastic Fiber

Here are the benefits of using Plastic Fiber:

• Lower Costs: Production and packaging costs are lower compared to glass optical fiber.
• Flexibility: POF is soft and non-brittle, allowing for greater bending without cracking. It can even be cut with a regular razor.
• Immunity to Noise: It doesn’t emit any radiation and is immune to noise, so it can be run alongside power cables without interference.
• Ruggedness and Ease of Installation: More rugged and flexible than glass, making it easier to install.
• Lightweight: Significantly lighter than glass fibers.
• Stress Resistance: Can withstand a fair amount of stress.

Drawbacks or Disadvantages of Plastic Fiber

Here are the limitations of Plastic Fiber:

• High Attenuation and Dispersion: Signal attenuation and dispersion are very high, making them unsuitable for long-distance communication systems.
• Temperature Sensitivity: The refractive index of the core and cladding changes rapidly at higher temperatures, affecting the Numerical Aperture (NA) and mode pattern.
• Lower Quality: Generally offers lower performance compared to glass optical fiber.
• Flammability: It’s flammable and should be used in selected applications only after careful analysis of safety considerations.