---
title: "Optical fiber advantages and disadvantages"
subject: "Basic Electronics Engineering"
chapter: 5
key: "semester_2/basic_electronics_engineering:optical-fiber-adv-disadv"
source: https://www.bctengineer.com/q/semester_2/basic_electronics_engineering/optical-fiber-adv-disadv
site: BCT Engineering
---

# Optical fiber advantages and disadvantages

Basic Electronics Engineering · Chapter 5: Communication System

- Asked in: 2074 Bhadra, 4 marks
- Video: [What are the Advantages and Disadvantages of Fiber Optic Cable - Network Wire](https://www.youtube.com/watch?v=pMR4YhyNM_4) — NETWORK WIRE
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_2/basic_electronics_engineering/optical-fiber-adv-disadv
- Whole chapter: https://www.bctengineer.com/md/semester_2/basic_electronics_engineering/chapter-5

## Question

What are the advantages and disadvantages of optical communication system?

## Short answer

Advantages include huge bandwidth, low attenuation, immunity to EMI, high security, small size, and safety. Disadvantages are high initial cost, difficult splicing, fragility, need for separate power, and dispersion limiting distance.

## Answer

Optical communication sends information as light pulses through optical fibers (core with higher refractive index than cladding, guiding light by total internal reflection).

#### Advantages

1. **Huge bandwidth:** supports Gbps to Tbps data rates and many channels.
2. **Low attenuation:** about 0.2 to 0.5 dB/km, so repeaters are needed only after tens of km.
3. **No EMI or crosstalk:** light is not affected by electrical noise, lightning or nearby cables.
4. **Security:** tapping is hard and detectable.
5. **Small size and light weight:** easy to install and handle compared with copper.
6. **Safe:** no sparks, no ground loops; safe in explosive areas.
7. **Cheap raw material:** silica (sand) is abundant.

#### Disadvantages

1. **High initial cost** of terminal equipment (transmitters, receivers, connectors).
2. **Difficult jointing and splicing:** needs special tools and trained persons.
3. **Fragile:** glass fiber breaks if bent too sharply or pulled; needs protective jacketing.
4. **One-way link per fiber:** two fibers are usually needed for two-way communication.
5. **Cannot carry electrical power** to repeaters or devices; a separate supply is needed.
6. **Dispersion and attenuation** limit the distance and rate in long links; repair is costly.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is the attenuation of fiber?
   A. About 20 dB/km
   B. Higher than coaxial
   C. About 0.2 to 0.5 dB/km, so repeaters are needed only after tens of km
   D. Zero
   Answer: C. Low loss is a main advantage. (Key point: Attenuation)

2. Which is a disadvantage of fiber?
   A. Difficult jointing and splicing; fragile glass
   B. EMI and crosstalk
   C. Small bandwidth
   D. Spark hazard
   Answer: A. It needs special tools and care. (Key point: Disadvantage)

3. Can fiber carry electrical power to repeaters?
   A. Yes, like copper
   B. Yes, using the cladding
   C. No; a separate supply is needed
   D. Only for short links
   Answer: C. Fiber is non-conducting. (Key point: Power)

4. Why is fiber safe in explosive areas?
   A. No sparks or electrical current
   B. It uses high voltage
   C. It heats the surroundings
   D. It is metallic
   Answer: A. No electrical current means no sparks. (Key point: Safety)

## Related in Basic Electronics Engineering

- [Communication system; optical fiber merits](https://www.bctengineer.com/question.md?key=semester_2%2Fbasic_electronics_engineering%3Adefine-comm-optical-merits) — Basic Electronics Engineering, chapter 5
- [Optical fiber advantages and labelled diagram](https://www.bctengineer.com/question.md?key=semester_2%2Fbasic_electronics_engineering%3Aoptical-fiber-adv-diagram) — Basic Electronics Engineering, chapter 5
- [Role of antenna; optical fiber pros and cons](https://www.bctengineer.com/question.md?key=semester_2%2Fbasic_electronics_engineering%3Aantenna-role-optical) — Basic Electronics Engineering, chapter 5
- [Optical fiber and its advantages](https://www.bctengineer.com/question.md?key=semester_2%2Fbasic_electronics_engineering%3Aoptical-fiber-advantages) — Basic Electronics Engineering, chapter 5, asked 5×
- [Communication system and block diagram](https://www.bctengineer.com/question.md?key=semester_2%2Fbasic_electronics_engineering%3Acomm-system-block-diagram) — Basic Electronics Engineering, chapter 5, asked 7×

## Related in other subjects

- [Elements of optical communication system](https://www.bctengineer.com/question.md?key=semester_6%2Fpropagation_and_antenna%3Aoptical-communication-elements) — Propagation and Antenna, chapter 6, asked 3×
- [Optical fiber advantages and disadvantages](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Aoptical-fiber-pros-cons) — Instrumentation II, chapter 5
- [Short note: Multi mode optical fiber](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Amultimode-fiber-short-note) — Data Communication, chapter 4
- [Short note: Optical fiber versus STP](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Aoptical-fiber-vs-stp) — Data Communication, chapter 4