Define Numerical Aperture of a step index fiber.

Give refractive index expression for step index fiber .

3. It is desired to make a single-mode fiber at an operating wavelength=1300 nm with ncore=1.505 and nclad= 1.502.Find the Numerical Aperture and core radius.

Define Mode-field diameter.

What is the function of an optical receiver and repeater?

For n1=1.55 and n2= 1.52, calculate the critical angle and Numerical aperture.

7. Determine the normalized frequency at 820 nm for a step inex fiber having a 25m radius. The refractive indexs of the clading and core are 1.45 and 1.47 respectively. How many modes propagate in this fiber at 820nm.

8.Distinguish meridional rays and skew rays.

9.State Snells law

10.Give the refractive index expression of a graded index fiber.

11.point source of light if 12 cm below the surface of a large body of water (n=1.33). What is the radius of the largest circle on the water surface through which the light can emerge? Find c from Snell's law.

12.Write down the wavelength regions corresponding to 1st 2nd and 3rd windows.

13.Whats critical angle of incidence?

14.What is cut-off condition?

15.typical relative refractive index difference for an optical fiber designed for long distance transmission is 1%. Estimate the numerical aperture for the fiber when the core index is 1.47.

16.Whats the effect of dispersion in an optical fiber?

17.Define signal attenuation

18.How does intrinsic absorption occur?

19.Identify the causes of scattering loss.

20.What is meant by mode coupling? What causes it?

21.What are the causes of absorption?

22.An optical signal has lost 55%of its power after traversing 3.5 km of fiber. What is the loss in dB/km of this fiber?

23.Give the expression of the effective number of modes that are guided by a curved multimode fiber of radius a.

24.Whats Urbachs rule?

25.What are the types of bends that can be subjected to a fiber?

26.What is meant by mode coupling? What causes it?

27.Distinguish between splice and connector.

28.What is Rayeligh Scattering?

29.What is meant by mechanical Splice?

30.What are the materials that predominantly take part in impurity absorption?