Which type of optical signal transmission is suited for longer distances in fiber optics?

Singlemode fiber is particularly suited for longer distances in fiber optics due to its design and functionality. It features a smaller core diameter, typically around 8 to 10 micrometers, which allows only a single mode of light to propagate through it. This minimizes modal dispersion, where different light modes travel at varying speeds and can lead to signal degradation over distances. Because singlemode fiber effectively prevents this dispersion, it can transmit data signals over much longer distances compared to other types of fiber.

Additionally, singlemode fiber is optimized for use with laser light sources, which can provide a coherent and focused light signal, further extending the transmission distance while maintaining signal integrity. This makes it the preferred choice for telecommunications, internet backbones, and long-haul fiber optic links.

In contrast, multimode fiber, while useful for shorter distances due to its larger core allowing multiple light modes, experiences more significant modal dispersion, which limits its effective range. Plastic optical fiber is generally used for shorter applications due to its higher attenuation losses compared to glass fibers. Photonic crystal fiber, while having unique properties, is still not as commonly used for standard long-distance communication as singlemode fiber. Thus, singlemode fiber is specifically advantageous for long-distance optical signal transmission.