B.TechSemester 42025-26Laser System And ApplicationsBOE412

Laser System And Applications (BOE412) - AKTU Question Paper 2025-26

B.Tech · Semester 4 · Free PDF Download

This is the official AKTU Laser System And Applications Previous Year Question Paper for B.Tech Semester 4, academic session 2025-26. Published by Dr. A.P.J. Abdul Kalam Technical University (AKTU/UPTU), Lucknow. Free PDF download — no login required.

Course:B.Tech

Semester:Semester 4

Session:2025-26

University:AKTU / UPTU

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Questions Asked in 2025-26

Laser System And Applications (BOE412) — complete question paper · 70 marks · 3 Hours

Section AAttempt all questions in brief. 02 x 7 = 14

a
Define coherence. What is temporal coherence?
b
What is population inversion? Why is it necessary?
c
What is the principle of laser action?
d
What is excimer laser?
e
Explain any two medical applications of lasers
f
Differentiate between spontaneous and stimulated emission
g
What are the different types of pumping methods?

Section BAttempt any three of the following: 07 x 3 = 21

a
Derive the relation between Einstein A and B coefficients
b
A laser emits light of wavelength 600 nm. Calculate:(i) Energy of one photon(ii) Number of photons emitted per second if power is 2 mW
c
Describe different techniques used for measurement of laser pulses
d
Describe the construction and working of ruby laser with diagram
e
Describe holography and its applications using laser

Section CAttempt any one part of the following: 07 x 1 = 07

a
Explain longitudinal and transverse coherence. Derive an expression for coherence length
b
The coherence length for a non-lasing light is 2.94x10-2 m and its wavelength is 5890. Calculate: (i) number of oscillations (ii) coherence time and spectral width
a
Discuss two, three and four level pumping schemes with diagrams
b
Define gain and derive the condition for threshold gain in lasers
a
Differentiate between continuous wave (CW) and pulsed lasers with examples
b
Describe the main components of a laser system with neat diagram
a
Explain Nd-YAG laser with its characteristics and applications
b
Explain the construction and working of He-Ne laser with energy level diagram
a
Explain the principle and applications of LIDAR
b
Explain various applications of lasers in medicine and surgery

Question text is extracted from the official AKTU question paper PDF above. Hindi translations are omitted — every question is printed in English in the original paper. Last verified: 2026-08-23.