Fiber Optics Flashcards
6 cards from real Telecommunications practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Fiber Optics flashcards as text
What physical phenomenon allows fiber optic cables to transmit light?
Answer: Total internal reflection
Total internal reflection causes light to bounce within the fiber core when it strikes the cladding at an angle below the critical angle.
What is the difference between single-mode and multimode fiber?
Answer: Single-mode has a smaller core and supports longer distances; multimode has a larger core for shorter distances
Single-mode fiber's smaller core (8-10 µm) allows only one light path, reducing dispersion and enabling longer transmission distances than multimode.
What does OTDR stand for and what is it used for?
Answer: Optical Time Domain Reflectometer; used to test fiber for faults and measure length
An OTDR (Optical Time Domain Reflectometer) sends light pulses into fiber and analyzes reflections to locate faults, splices, and measure cable length.
What wavelength does standard single-mode fiber primarily use for long-haul transmission?
Answer: 1550 nm
1550 nm (C-band) is the preferred wavelength for long-haul single-mode transmission because optical fiber has minimum attenuation at this wavelength.
What does WDM stand for in fiber optics?
Answer: Wavelength Division Multiplexing
WDM (Wavelength Division Multiplexing) combines multiple optical signals at different wavelengths on a single fiber, multiplying capacity.
What causes chromatic dispersion in fiber optic cables?
Answer: Different wavelengths traveling at slightly different speeds
Chromatic dispersion occurs because different wavelengths of light travel at slightly different velocities in the fiber, causing pulse broadening.