Syllabus

🔹 Unit I – Interference

Hours: 7 | Marks: 7

1) Introduction to Interference

Definition:

जेव्हा दोन coherent light waves superpose होतात तेव्हा interference होते.

2) Principle of Superposition

Statement:

Resultant amplitude = Sum of individual amplitudes

3) Conditions for Steady Interference

Conditions:

• Same wavelength

• Same frequency

• Constant phase difference

4) Interference in Thin Films

Example:

Soap bubble colours

Due to:

Reflected light and transmitted light

5) Newton’s Rings

Formation:

Circular rings formed due to interference

Application:

Wavelength measurement

Formula:

$$\lambda = \frac{D^2_{n+p} - D^2_n}{4pR}$$

6) Michelson Interferometer

Principle:

Interference due to path difference

Uses:

Wavelength measurement

Numericals included

🔹 Unit II – Diffraction

Hours: 8 | Marks: 8

1) Rectilinear Propagation

Light travels in straight line

2) Types of Diffraction

Fresnel Diffraction

Near field

Fraunhofer Diffraction

Far field

3) Single Slit Diffraction

Pattern of bright and dark bands

4) Double Slit Diffraction

Combination of interference and diffraction

5) Diffraction Grating

Principle:

Multiple slit interference

Formula:

$$d \sin \theta = n\lambda$$

Application:

Wavelength determination

Numericals included

🔹 Unit III – Polarization

Hours: 7 | Marks: 7

Definition:

Light vibration in one plane

1) Double Refraction

Splitting of light into two rays

Example:

Calcite crystal

2) Phase Retardation Plates

Quarter Wave Plate

Produces circular polarization

Half Wave Plate

Changes polarization direction

3) Nicol Prism

Used to produce polarized light

4) Elliptical and Circular Polarization

🔹 Unit IV – Laser

Hours: 8 | Marks: 8

Definition:

LASER:

Light Amplification by Stimulated Emission of Radiation

Characteristics of Laser

• Highly directional

• Monochromatic

• Coherent

Types of Emission

Absorption

Atom absorbs energy

Spontaneous Emission

Natural emission

Stimulated Emission

Laser emission

Population Inversion

Excited state atoms > ground state

Pumping Process

Energy supply

Components of Laser

• Active medium

• Pumping source

• Resonator

Types of Laser

Ruby Laser

Solid state laser

He-Ne Laser

Gas laser

Semiconductor Laser

Used in electronics

Applications of Laser

Medical

Eye surgery

Industrial

Cutting

Agriculture

Land leveling

Research

Scientific experiments

1. Describe the conditions for interference and apply the superposition

principle to analyze thin-film interference and Newton’s rings.

2. Solve numerical problems related to wavelength determination using

interference (Michelson interferometer) and diffraction (grating)

techniques.

3. Distinguish between Fresnel and Fraunhofer diffraction and interpret

diffraction patterns from single/double slits.

4. Explain polarization mechanisms (e.g., double refraction, quarter/halfwave

plates) and demonstrate how to produce polarized light.

5. Illustrate the working principles of lasers, including population inversion

and pumping processes in 3-level/4-level systems.

6. Compare the construction and operation of Ruby, He-Ne, and

semiconductor lasers.

7. Discuss real-world applications of lasers and polarized light across diverse

fields (e.g., medical surgery, optical communications).