Certified Fiber Optics Practice Exam

Light must enter through the cone of what?

1. Reflection

2. Transmission

3. Acceptance

4. Diffraction

The correct answer is: Acceptance

The correct answer, "Acceptance," refers to the concept in fiber optics where light must enter the fiber at a specific angle that falls within a designated cone known as the acceptance cone. This angle is determined by the numerical aperture of the fiber, which defines how much light the fiber can effectively capture and transmit. When light is introduced to a fiber optic cable, it needs to be aimed within this acceptance cone; otherwise, the light will not couple efficiently into the fiber, leading to signal loss. This principle is crucial for ensuring effective communication over fiber optic networks, as proper light entry maximizes the amount of light transmitted through the fiber core. In contrast, the other options—reflection, transmission, and diffraction—do not directly pertain to the specific angle at which light must enter a fiber. Reflection relates to how light bounces off surfaces, transmission refers to the propagation of light through the medium, and diffraction deals with the bending of light waves around obstacles. These concepts are significant in various contexts, but they do not capture the critical aspect of how light must enter a fiber optic cable effectively.