Fiber Optic System Components and Equipment Flashcards

What is an optical attenuator used for in a fiber optic link?

Answer: Reduce optical power to prevent receiver saturation

Optical attenuators intentionally reduce signal power to prevent overloading a receiver when the transmitted power exceeds the receiver's dynamic range.

A fiber optic patch panel in a telecommunications room primarily serves what function?

Answer: Provide a flexible cross-connect point between backbone and horizontal cabling

Patch panels provide a centralized, organized cross-connect interface where technicians can reroute connections using patch cords without disturbing permanent cabling.

What is the difference between a simplex and a duplex fiber optic cable assembly?

Answer: Simplex has one fiber; duplex has two fibers in one jacket for separate TX and RX paths

A simplex assembly contains one fiber for one-way transmission, while a duplex assembly contains two fibers allowing separate transmit and receive paths.

In DWDM systems, what is the typical channel spacing defined by the ITU-T G.694.1 grid?

Answer: 100 GHz (approximately 0.8 nm) or 50 GHz (approximately 0.4 nm)

ITU-T G.694.1 defines the DWDM frequency grid with standard spacings of 100 GHz (~0.8 nm) and 50 GHz (~0.4 nm) in the C-band.

What is the function of a fiber optic isolator in a laser transmitter circuit?

Answer: Prevent back-reflected light from entering and destabilizing the laser source

Optical isolators allow light to pass in only one direction, blocking back-reflections that would cause laser instability, noise, or damage.

What component in a fiber optic receiver converts incoming optical signals into electrical signals?

Answer: Photodetector (PIN diode or avalanche photodiode)

The photodetector (typically a PIN diode or APD) performs O/E conversion by generating an electrical current proportional to the incident optical power.