Optical Communication — Summer 2019

Define : Skew ray, Meridional ray.

Compare single mode and Multi mode step index and graded index optical fiber

List the factors that decide the performance of optical reception and explain it. Also draw and explain eye diagram in detail.

Explain various fiber modes

Explain scattering loss in optical fiber.

Explain with neat and clean diagram : The plasma activated chemical vapor deposition (PCVD) technique for the production of optical fiber

Amultimode step index fiber with a core diameter of 100 μm and a relative index difference of 1.5% is operating at a wavelength of 0.85 μm. If the core refractive index is 1.485, calculate: (i) Normalized frequency of fiber (ii) Total number of guided modes.

Compare Direct band gape and Indirect band gape materials

Explain structure of Edge double hetero junction LED

Derive the equation for the power launched from LED Source in to a S.I. fiber

Compare LED and LASER diode as a light source in fiber optic communication

Explain structure of Surface LED

Derive LASER rate equation1

Define the following terms related to photo detector. (1) Responsivity (2) Quantum efficiency (3) Cut off wavelength

Discuss the fiber splicing techniques with necessary sketches.

Explain Optical Time Domain Reflectometry (OTDR) method with its benefits over other techniques

Explain nature of light and its various polarization

Explain principal of Pi Nphoto detector with its energy band diagram

Discuss the need of optical Amplifier and also describe the architecture and amplification mechanism of Erbium Doped Fiber Amplifier. (EDFA)

Explain : Snell’s law.

Discuss system features of WDM and explain WDM in brief also Draw diagram of a typical WDM link containing various components

Explain in detail : SONET/SDH

Short note : Dispersion in fiber cable

Explain the three key transient process involved in LASER action.

Explain reach through avalanche photo diode structure with its electric field and multiplication concept.