Question

In the first window of optical fibre, light sources are generally:

• A. GaAlP
• B. GaAlBr
• C. GaAlAs
• D. GeAlAs

Hint:

The first window in optical fibre typically uses light sources like GaAlAs, which emit in the near-infrared region.

Answer 1

The Correct Option is C

In the first window of optical fibre communication, light sources such as GaAlAs (Gallium Aluminium Arsenide) are commonly used. GaAlAs is a semiconductor material that emits light in the near-infrared region, which is ideal for transmission in the first window of optical fibre, typically around 850 nm.
Final Answer: \[ \boxed{\text{(3) GaAlAs}} \]