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This section includes 11 Mcqs, each offering curated multiple-choice questions to sharpen your Optical Communications knowledge and support exam preparation. Choose a topic below to get started.
1. |
The external power efficiency of an injection laser with a GaAs is 13% having band gap energy of 1.64 eV. Determine external power efficiency. |
A. | 0.198 |
B. | 0.283 |
C. | 0.366 |
D. | 0.467 |
Answer» B. 0.283 | |
2. |
A correct DH structure will restrict the vertical width of waveguide region is? |
A. | 0.5 m. |
B. | 0.69 m |
C. | 0.65 m |
D. | Less than 0.4 m |
Answer» E. | |
3. |
Single longitudinal mode operation is obtained by __________ |
A. | Eliminating all transverse mode |
B. | Eliminating all longitudinal modes |
C. | Increasing the length of cavity |
D. | Reducing the length of cavity |
Answer» E. | |
4. |
The spectral width of emission from the single mode device is __________ |
A. | Smaller than broadened transition line-width |
B. | Larger than broadened transition line-width |
C. | Equal the broadened transition line-width |
D. | Cannot be determined |
Answer» B. Larger than broadened transition line-width | |
5. |
Laser modes are generally separated by few __________ |
A. | Tenths of micrometer |
B. | Tenths of nanometer |
C. | Tenths of Pico-meter |
D. | Tenths of millimeter |
Answer» C. Tenths of Pico-meter | |
6. |
Gain guided laser structure are __________ |
A. | Chemical laser |
B. | Gas laser |
C. | DH injection laser |
D. | Quantum well laser |
Answer» D. Quantum well laser | |
7. |
A particular laser structure is designed so that the active region extends the edges of devices. |
A. | True |
B. | False |
Answer» B. False | |
8. |
T is known as slope quantum efficiency. |
A. | True |
B. | False |
Answer» C. | |
9. |
Injection laser have a high threshold current density of __________ |
A. | 10<sup>4</sup>Acm<sup>-2</sup> and more |
B. | 10<sup>2</sup>Acm<sup>-2</sup> |
C. | 10<sup>-2</sup>Acm<sup>-2</sup> |
D. | 10<sup>-3</sup>Acm<sup>-2</sup> |
Answer» B. 10<sup>2</sup>Acm<sup>-2</sup> | |
10. |
In semiconductor injection laser, narrow line bandwidth is of the order? |
A. | 1 nm or less |
B. | 4 nm |
C. | 5 nm |
D. | 3 nm |
Answer» B. 4 nm | |
11. |
Stimulated emission by recombination of injected carriers is encouraged in __________ |
A. | Semiconductor injection laser |
B. | Gas laser |
C. | Chemist laser |
D. | Dye laser |
Answer» B. Gas laser | |