The three windows in case of optical fibres to be used for communication are:
- A. 850 nm
- B. 1310 nm
- C. 1410 nm
- D. 1110 nm
- E. 1550 nm
Choose the correct answer from the options given below:
- A, B and C only
- A, B and D only
- B, C and D only
- A, B and E only
Solution
Step 1: Recall the standard optical communication windows
Optical fiber communication systems commonly operate in three low-loss wavelength windows:
- First Window = 850 nm
- Second Window = 1310 nm
- Third Window = 1550 nm
Step 2: Compare with the given options
| Option | Wavelength | Communication Window? |
|---|---|---|
| A | 850 nm | ✔ Yes |
| B | 1310 nm | ✔ Yes |
| C | 1410 nm | ✘ No |
| D | 1110 nm | ✘ No |
| E | 1550 nm | ✔ Yes |
Step 3: Select the correct combination
The valid optical communication windows are:
850 nm, 1310 nm, and 1550 nm
Therefore, the correct combination is:
A, B and E only
Correct Option: 4
Further Reading:
GATE EC Previous Year Papers with Solutions