Fiber Optics Flashcards

Which splicing method typically produces the lowest insertion loss in single-mode fiber?

Answer: Fusion splice

Fusion splicing melts fiber ends together creating a near-seamless joint, typically yielding losses below 0.1 dB.

What is the primary purpose of an optical time-domain reflectometer (OTDR)?

Answer: Locate faults and measure loss along a fiber link

An OTDR sends pulses into the fiber and analyzes backscattered light to locate faults, splices, and measure distance-based loss.

What does 'bend radius' refer to in fiber optic installations?

Answer: The minimum curve radius a fiber can be bent without excessive signal loss

Exceeding the minimum bend radius causes microbending loss as light escapes the core through the cladding.

Which fiber optic connector type uses a push-pull latching mechanism and is common in data center applications?

Answer: LC connector

LC (Lucent Connector) uses a push-pull latch similar to an RJ-45 and has a small form factor suited for high-density data center use.

What does 'numerical aperture' (NA) describe in a fiber optic cable?

Answer: The light-gathering ability and acceptance cone of the fiber

Numerical aperture defines the half-angle of the cone of light a fiber can accept, determined by the refractive index difference between core and cladding.

In fiber optics, what does 'modal dispersion' cause?

Answer: Pulse spreading that limits bandwidth over distance

Modal dispersion occurs in multimode fiber when different modes travel at different speeds, causing pulses to spread and limiting data rates.

What type of fiber is most commonly used for long-haul telecommunications exceeding 10 km?

Answer: Single-mode 9/125 µm

Single-mode fiber with a 9 µm core eliminates modal dispersion and supports very long transmission distances at high bandwidths.