B.Sc. 3rd Semester

 Unit I

Interference: Concept of Spatial and temporal coherence, coherence length, coherence time, 

Definition and propagation of wavefront, Huygens principle of secondary wavelets, 

Method to produce coherent sources. 

• Interference by division of wavefront: 
• Young’s Double Slit Experiment, Types of fringes, 
• Fresnel’s Bi-Prism, 
• Measurement of wavelength and 
• thickness of a thin transparent sheet. 
• Interference by division of amplitude– 
• Thin films 
1. Parallel films: 1. Interference by reflected rays, 2. Interference by transmitted rays
• Michelson’s Interferometer, the shape of fringes, 
• Applications of Michelson's Interferometer
1. Measurement of wavelength, 
2. The difference between two spectral lines, and 
3. The thickness of a thin transparent sheet. 
• Fringes of equal inclination (Haidinger Fringes)
2. Wedge-shaped films, 
• Newton’s Rings: 
1. Measurement of wavelength and refractive index. 
• Fringes of equal thickness (Fizeau Fringes). 

Unit II

Diffraction: 

1. Fresnel Diffraction: 
• Half-period zones. 
• Zone plate. 
• Multiple Foci of zone plate, 
• Comparison between zone plate and convex lens, 
• Fresnel Diffraction pattern at 
• a circular aperture, 
• straight edge, and 
• a rectangular slit using half-period zone analysis. 
2. Fraunhofer diffraction: 
• Single slit; 
• Double slit. 
• Multiple slits, missing order, 
• Diffraction grating, 
• Resolving power of grating, 
• Rayleigh’s criterion of resolution. 

Unit III

Polarization: 

1. Plane polarized light 
2. Circularly polarized light 
3. Elliptically polarized light, 

Production of plane-polarized light 

1. by reflection 
2. by refraction 
3. by double refraction, and 
4. by dichroism (Polaroid), 

Brewster’s law,     Law of Malus,     Huygens’ wave theory of double refraction, 

Analysis of Polarized light: Nicol prism, 

Quarter wave plate, and half-wave plate, 

Optical activity, Laws of optical activity, and 

Fresnel’s explanation of optical activity; Specific rotation, 

Polarimeters: 

1. Laurent’s half shade Polarimeter and 
2. Biquartz Polarimeter. 

Unit IV

Quantum Optics and photonics 

(i) Laser: Spontaneous and stimulated emission, Einstein’s A & B coefficients, population inversion, methods of optical pumping. Ruby, He-Ne, and Semiconductor laser (Principle and working). 

(ii) Holography: Principle of holography, Theory of construction and reconstruction of image, applications of holography. 

(iii) Fiber Optics: Introduction to optical fiber, types of optical fiber, Total internal reflection, Explanation of propagation of light through an optical fiber