Optical Communication Online Test

1. The optimum filter bandwidth is typically in the range ________________

2. When determining performance of a photo detector ___________ is often used.

3. The GRIN-rod lens can produce a collimated output beam with a divergent angle αof between _____________ from a light source situated on, or near to, the opposite lens face.

4. The 3 dB electrical bandwidth B is 42 MHz. Determine 3dB optical bandwidth Bopt.

5. The use of __________ was undertaken to separate the polarization in an analog to digital conversion.

6. _______________ is constructed using erbium-doped glass.

7. How many types of optical Ethernet connections are developed?

8. The linear variation of refractive index with the electric field is known as the ________

9. Determine the peak output voltage if efficiency is 70%, wavelength is 0.85μm and output power is 1mW.

10. A monochromatic wave propagates along a waveguide in z direction. These points of constant phase travel in constant phase travel at a phase velocity V_p is given by?

11. What is the minimum value of accuracy in diameter is needed to avoid radiation losses in the fiber?

12. The probe signal is inverse to that of the pump signal.

13. An SOA has length of 35.43×10^-3m, at 30 dB gain. Determine net gain coefficient.

14. Line-width narrowing is achieved in DFB lasers by a strategy referred as _______________

15. The behavior of laser occurring when current is increased above threshold particularly is?

16. Which of the following co-dopant is not employed by neodymium and erbium doped silica fiber lasers?

17. The 10-90% rise times for components used in D-IM analog optical link is given. (LED=10ns, Intermodal=9ns/km, Chromatic=2ns/km, APD = 3ns). Link is of 5km. It has an optical bandwidth of 6MHz. Determine maximum permitted system rise time.

18. ___________ removes the light propagating in the cladding.

19. Compute the photocurrent of RAPD having multiplication factor of 36.7 and output current of 7μA.

20. Waveguide structure provides high quantum efficiency.

21. The optical bandwidth is _____________ the electrical bandwidth.

22. How many types of misalignments occur when joining compatible fiber?

23. The narrow line-width obtained under the CW operation for quarter wavelength shifted DFB laser is ________________

24. The Nd: YAG laser has a narrow line-width which is ________________

25. Plastic fibers are less widely used than glass fibers.

26. Magneto-optic devices can be used to function as isolators.

27. Modified Chemical Vapor Deposition (MCVD) process is also called as an inside vapor phase oxidation (IVPD) technique.

28. Estimate the minimum transmitter power if number of photons per bit are 150, wavelength 1.3 micrometer with an optical bandwidth of 20 THz.

29. A multimode fiber has many cutoff wavelengths.

30. How many simultaneous channels can be provided in a band DGE(Dynamic gain equalizer)?

31. A single-mode step-index fiber or multimode step-index fiber allows propagation of only one transverse electromagnetic wave.

32. For particular materials with smaller bandgap energies operating in _____________ wavelength, the linewidth tends to ______________

33. What is the full form of ETDM?

34. The ___________ process takes place in both extrinsic and intrinsic semiconductors.

35. What is the exception in the similarities between the optical Ethernet and the Ethernet LAN?

36. Direct absorption requires assistance of photon.

37. _________ semiconductor laser sources generally have broader bandwidths.

38. How many categories exists in case of cable design?

39. A homo-junction is an interface between two adjoining single-crystal semiconductors with different band-gap energies.

40. Stress corrosion must be considered while designing and testing optical fiber cables.

41. FET preamplifiers provide higher sensitivity than the Si-bipolar device.

42. Absorption losses due to atomic defects mainly include ___________

43. ________ can be operated in three connections.

44. Which is the unit of measurement of attenuation in optical fibers?

45. The ___________ provides information about the physical path and wavelength assignment for all active light paths.

46. A four-port FBT coupler has 60μW optical power launched into port one. The output powers at ports 2, 3, 4 are 0.0025, 18, and 22 μW respectively. Find the split ratio?

47. ______________ facilitates the doubling of the feasible spectral efficiency through the transmission of independent information in each of the two orthogonal polarizations.

48. Optical MAN’S are usually structured in _______ topologies.

49. Optical fibers for communication use are mostly fabricated from ___________

50. What type of receivers are used to provide wideband operation, low-noise operation?