Which type of fiber-optic transmission requires a laser transmitter?

Single-mode fiber-optic transmission requires a laser transmitter due to its design and operational principles. Single-mode fiber has a small core diameter, typically around 8 to 10 microns, allowing only a single mode of light to propagate through it. This characteristic provides high bandwidth over long distances and reduces modal dispersion, making it ideal for long-haul telecommunications.

Laser transmitters are used with single-mode fiber because they emit a coherent light source with a narrow spectral width. This coherence enables the light to travel efficiently through the single mode, minimizing losses and maximizing the distance the signal can travel without degradation.

In contrast, multimode fiber, which has a larger core diameter, can accept light from LED sources, allowing multiple light rays to travel through the fiber simultaneously. Plastic optical fiber generally uses LED emitters as well, primarily due to its larger core and different material properties. Hybrid fiber can incorporate various technologies but does not specifically require a laser transmitter for operation.