Fiber Optics MCQ Questions Answers

1. What is the relationship between refractive index (n1) of core and refractive index (n2) of cladding for an optical fiber?

2. Dispersion in optical fibers causes distortion in _______.

3. Light emitting diodes (LED's) are:

4. Dark spot defects (DSD's) occur in:

5. The fiber gyroscope is an ______.

6. SONET is _________.

7. Silicon reach through avalanche photodiodes has _______.

8. For a step index fiber, relationship between numerical aperture (NA) and coupling efficiency (ηc) is ________.

9. Germanium photodiodes are generally not preferred in the optical fiber system because of _________.

10. Homodyne detection is used for _______.

11. Near-field scanning method is used to measure:

12. Hydrogen absorption by optical fiber causes _______.

13. FDDI is _______.

14. What happens when dispersion occurs?

15. Superluminescent LED's are preferred because of _______.

16. In p-i-n photodiodes 'i' stands for:

17. The information carrying capacity of optical fibers is in the range of:

18. Dark line defects (DLDs) occur when:

19. LED is more suitable for analog transmission because of its _______.

20. Macro bending losses in optical fibers can be reduced by designing the fibers with ________.

21. What is the thermal noise current it in a resistor R expressed in its mean square value? where, K is Boltzmann's constant, T is absolute temperature and B is the bandwidth

22. LASER stands for:

23. Germanium avalanche photodiodes can be used for _______.

24. Index optical fibers are sometimes referred to as:

25. The output power of a LASER is greater than that of a LED because of _____.

26. Total internal reflection takes place at angles ________.

27. The population inversion phenomenon in optical sources occurs when _________.

28. Which one is a characteristic of an injection LASER?

29. Which one is a fiber dispersion measurement method?

30. The first generation optical fibers are fabricated from:

31. The cutback technique is a/an _______.

32. The rays which travel in a helical path through an optical fiber are called ______.

33. Which one is a type of non-linear scattering?

34. Which one is an Optical System Design Software?

35. For a profile parameter (α)=1, the profile shape of refractive index for a graded index fiber will be _______.

36. When optical power is incident on the photo detector during the 0 bit period, then the system is said to exhibit _______.

37. Intersymbol interference (ISI) in optical fibers occurs due to ______.

38. FDDI can support a data rate of

39. For a multimode optical graded index fiber, the profile parameter (α) will be equal to:

40. Mirrors are placed in LASER optical sources to maintain conditions for ________.

41. The LASER is a/an

42. COBRA (commutateur optique binaire rapide) is an ________.

43. For an ideal photo detector, the absorption coefficient must be ______.

44. The vapor-phase deposition technique is used to produce _______.

45. SOLITON is a/an ______.

46. Dispersion is low in the __________.

47. Dispersion is the lowest in a________.

48. Avalanche photodiodes are ________.

49. Numerical aperture (NA) is related to the refractive indexes of core (n1) and cladding (n2) when,

50. Scattering losses happen due to:

51. Intermodal dispersion is less in a __________.

52. Optical time domain reflectometry (OTDR) is a/an ________.

53. What would the optical return loss (ORL) be defined as when r-fresnal reflection occurs at a fiber-air interface?

54. Graded-index fibers have:

55. IEEE 802.5 is a/an ________.

56. Metallic impurities are eliminated from optical fiber by:

57. Optical bandwidth (OB) relates to electrical bandwidth (EB) when

58. Surface emitter LEDs have high radiance because _______.

59. What is signal attenuation in an optical fiber where P1=Input power and P0=Output power

60. Which phenomenon does not let light rays escape an optical fiber?

61. A multimode graded index fiber exhibits total pulse broadening of 0.2 µsec over a distance of 10Km. Estimate the maximum possible bandwidth assuming that there is no inter-symbol interference.

62. The Nd:YAG LASER is a/an_______.

63. One polarization maintaining fiber operates at a wavelength of 1.5 µm and has a beat length of 0.6mm. Its modal birefringence is given by _______.

64. The refractive index is defined as the ratio of ____________.

65. Quantum efficiency (η) is defined as

66. When microwave frequency rather than radio frequency subcarriers are employed, the strategy is usually referred to as ______.

67. What does TPON stand for?

68. Rayleigh scattering is a ________.