Laser Physics Important Questions

Bsc/Msc Physics 

Unit 1: Basic Principles of Laser

1. What is a laser, and how does it different from conventional light sources?
2. Explain spontaneous and stimulated emission with examples.
3. Define Einstein coefficients and their role in laser action.
4. Explain Einstein's coefficient A and B?
5. What is the concept of light amplification in lasers?
6. Describe necessary conditions for Laser action?
7. Describe population inversion and its necessity in laser operation/action.
8. What are the different laser pumping schemes for two and three-level systems?
9. Explain the threshold condition for laser oscillation and its significance.
10. What is the principle of Laser action?

Unit 2: Properties of Laser Beams and Resonators

1. What are the essential Characteristics of laser beams?
2. Define temporal coherence and spatial coherence. How are they different?
3. Explain the significance of directionality in laser beams.
4. What is the importance of monochromaticity in laser operation?
5. Describe the structure and function of a laser resonator.
6. What are the vibrational modes of resonators, and how do they affect laser output?
7. How does laser amplification occur within a resonator?
8. Explain the working principle of an open resonator.
9. Distinguish between spatial and temporal coherence in laser emission. How they govern the laser action?

Unit 3: Types of Lasers

1. Classify different types of lasers based on their active medium.
2. What is a Ruby laser? Explain its construction, principle, working, merit and demerit points in detail.
3. Describe the working principle of an Nd:YAG laser.
4. What is a Nd:YAG laser? Explain its construction, principle, working, merit and demerit points in detail?
5. What are semiconductor lasers, and how do they function?
6. What is semiconductor laser? Explain its construction, principle, working, merit and demerit points in detail?
7. Deduce the threshold condition of oscillation of laser in semiconductors?
8. Explain the working of a gas laser with an example.
9. How does a He-Ne laser generate a coherent light beam?
10. What is a He-Ne ( Helium-Neon) laser? Explain its construction, principle, working, merit and demerit points in detail.
11. What is a carbon dioxide laser, and what are its applications?
12. What is a CO2 laser? Explain its construction, principle, working, merit and demerit points in detail?
13. Describe the basic principle of liquid and dye lasers.
14. Derive oscillation conditions of a dye laser?
15. What are chemical lasers? Explain its working principle?
16. Explain in detail HCl and HF lasers?

Unit 4: Applications of Lasers

1. What is holography, and how is it related to lasers?
2. What is the difference between a hologram and an ordinary photographic negative?
3. Explain the principle and theory behind holograms.
4. How is an image reconstructed using holography?
5. Explain working, principle, construction and applications of Holography?
6. What are the key characteristics of holographs?
7. How are lasers used in chemistry and optics?
8. Explain the industrial applications of lasers in welding and cutting.
9. How does laser hole drilling work?
10. Discuss the medical applications of lasers in surgery and treatment.
11. Write a detailed account of application of laser in the field of chemistry, industry and in medical field?

Unit 5: Non-Linear Optics

1. What is nonlinear optics, and why is it important?
2. Explain the concept of harmonic generation in optics.
3. What are second and third harmonic generation? How do they differ?
4. Describe about harmonic generation of light with first and second harmonic of polarisation?
5. What is phase matching, and why is it necessary in nonlinear optics?
6. Describe the process of optical mixing in laser applications.
7. Explain the principle of parametric generation of light.
8. What is self-focusing of light, and how does it occur?
9. What is Nonlinear optics?

Advance Questions

• Compare and contrast spontaneous and stimulated emission in terms of their physical processes.
• How does the coherence property of laser beams make them suitable for holography?
• Why do different types of lasers operate at different wavelengths?
• Discuss the limitations and challenges in achieving high-powered laser beams.
• How does nonlinear optics influence the future of laser technology?
• Explain how phase matching enhances the efficiency of frequency conversion processes in nonlinear optics.