Give the comparison of Step Index and Graded Index Fibers.
[3 marks]Briefly Describe the block diagram of Optical Communication Systems.
[4 marks]Amultimode step index fiber has a refractive index difference of 1% and a core refractive index of 1.5.The number of modes propagating at a wavelength of 1.3μm is 1600.Calculate the acceptance angle, numerical aperture and the diameter of the fiber core.
[7 marks]Explain the significance of Carrier confinement related to the optical source.
[3 marks]Atypical LED emits light at a center wavelength of 920nm with Δλ=20nm, Calculate the Δf.
[4 marks]How does material dispersion occur in an optical fiber. Obtain the expression for group delay τ resulting from the material mat dispersion and from this, deduce the relation for the pulses spread σ in terms of material dispersion D ( λ). mat mat
[7 marks]Define signal attenuation and how is it mathematically expressed. Explain the Bending losses ( Micro bending losses, Macro bending losses).
[7 marks]Mention difference between Electrical bandwidth and optical bandwidth.
[3 marks]“The optical power launched into a fiber does not depend on the wavelength of the source but only on it’s brightness” Justify.
[4 marks]Briefly discuss the possible sources of noise in optical receivers.
[7 marks]Mention difference between Indirect band gap material and direct band gap material.
[3 marks]What is equilibrium numerical aperture. Give the significance of the same.
[4 marks]Explain detection process in the p-n photodiode. Define the quantum efficiency and responsivity of a photo detector.
[7 marks]Define with reference to eye diagram: (1) Width of eye opening (2) Timing jitter.
[3 marks]Discuss optical power loss model for a point to point link.1
[4 marks]Explain the performance of passive linear bus and also prove that optical power available at a particular node decreases with increasing distance from source.
[7 marks]Define Qfactor for digital transmission through optical cable.
[3 marks]Consider a 30-km long optical fiber that has an attenuation of 0.8 dB/km at 1300 nm. If 200 μW of optical power is launched into the fiber find out the optical output power Pout.
[4 marks]Write short notes on Syncronous optical fiber networks(SONET).
[7 marks]Discuss the Cut back technique for attenuation measurement.
[3 marks]Write short note on EDFA .
[4 marks]For a 2x2 fiber coupler show that the phase of the driven fiber always lags 90° behind the phase of the driving fiber. Also define the following related to optical coupler: (1) splitting ration (2) Excess loss (3) Insertion loss (4) Crosstalk
[7 marks]Explain any one method for optical dispersion measurement.
[3 marks]Write short note on Raman Amplifier.
[4 marks]Explain Mach-Zehnder Interferometer (MZI) multiplexer in detail.
[7 marks]