Optoelectronic Devices and Applications (INDSE8D) — DU B.Sc. (Hons) Instrumentation Previous Year Question Papers

(c) If electric field of a plane wave is E = 100sin (108£ -3x), find the wave velocity. Define optical waveguide. Write any two classifications. Differentiate between ordinary and extraordinary ray. A wave has angular frequency 4xl0]5 rad/s and wave number 2xl07 in-i. Find phase velocity. Define acousto-optic effect. Describe about the semiconductor optical amplifier (SOA). Derive the electromagnetic wave equation from Maxwell's equations in free Space. Derive Fresnel' s equations for reflection and transmission at boundary. Explain the phenomenon of optical tunnelling with a suitable diagram. (7) Derive V-number expression and detemine whether fiber is single mode for a = 5irm, Numerical Aperture OVA) = 0.1, ^ = 1.3Hm. What are fiber optic wave-plates? Explain how birefringence in optical fibers is used to realize quarter-wave and half-wave plates. Distinguish between s.tep-index and graded-index fiber. (c) Derive relation between phase shift and applied voltage in electi.o-optic (8) Explain circular and elliptical polarization mathematically. Calculate phase difference required for circular polarization. Calculate modulation index if applied voltage is 2V and half-wave voltage, VI = 4V. (b) Explain working of semiconductor optical Amplifiers (SOA). Calculate gain in dB for input 5 mw and output 100 mw. Dei.ive expi.ession for photoconductive gain. Caloulate gain for given canier lifetime and transit time. (c) If threshold cuITent is 20 rnA and operating curent is 50 rnA, find excess current. (3) two dielectric media. And also obtain the condition for Brewster's angle. a) Design a half-wave plate for wavelength 633 nm with birefringence, An =0.008. (7) (c) Calculate penetration depth if wavelength is 600 nm and incident angle is slightly greater (3) than critical angle. Q.7 (a) Explain heterojunction concept with band diagram. Calculate cut off wavelength (7) and responsivity. Derive the frequency relation for third-harmonic generation (THG). (6) Define LDR and its working principle. (5)