What part of the electromagnetic spectrum is used by fiber optic systems?

What part of the electromagnetic spectrum is used by fiber optic systems?

• A. Ultraviolet
• B. Infrared
• C. Visible
• D. Microwave

Answer: (B)

Fiber optics use infrared light because silica glass is highly transparent in the infrared telecom windows around 1300–1550 nm, where attenuation is the lowest and dispersion can be managed for long-distance data transmission. Ultraviolet light is absorbed and can damage the material, and visible light experiences more attenuation and scattering in fiber, making it inefficient for long runs. Microwaves don’t propagate well in standard optical fibers since the guiding mechanism is optimized for optical frequencies. This combination makes infrared the practical and widely used region for fiber optic communication.

Fiber optics use infrared light because silica glass is highly transparent in the infrared telecom windows around 1300–1550 nm, where attenuation is the lowest and dispersion can be managed for long-distance data transmission. Ultraviolet light is absorbed and can damage the material, and visible light experiences more attenuation and scattering in fiber, making it inefficient for long runs. Microwaves don’t propagate well in standard optical fibers since the guiding mechanism is optimized for optical frequencies. This combination makes infrared the practical and widely used region for fiber optic communication.