Diffraction

Introduction to Diffraction
Definition: The bending of waves around obstacles or through openings
Types of Diffraction:
- Single-Slit Diffraction
- Double-Slit Diffraction
- Diffraction Grating
Diffraction and Interference
Applications of Diffraction

Single-Slit Diffraction

Explanation of Single-Slit Diffraction
Conditions for Single-Slit Diffraction to Occur
Diffraction Pattern
Intensity Distribution
Equation for Single-Slit Diffraction:
- Sin(θ) = mλ/a

Double-Slit Diffraction

Explanation of Double-Slit Diffraction
Conditions for Double-Slit Diffraction to Occur
Interference Pattern
Bright and Dark Fringes
Equation for Double-Slit Diffraction:
- dsinθ = mλ

Diffraction Grating

Introduction to Diffraction Grating
Construction of Diffraction Grating
Diffraction Grating Equation:
- dsinθ = mλ
Calculating Wavelength using Diffraction Grating
Example: Finding the Wavelength from a Diffraction Grating Experiment

Diffraction and Interference

Relationship between Diffraction and Interference
Explanation of Interference in terms of Waves
Diffraction as a Result of Interference
Example: Diffraction and Interference in Double-Slit Experiment
Applications of Interference and Diffraction

Diffraction and Interference (Contd.)

Young’s Double-Slit Experiment
Experimental Setup
Path Difference
Constructive and Destructive Interference
Conditions for Constructive and Destructive Interference

Diffraction and Interference (Contd.)

Equations for Constructive and Destructive Interference:
- Constructive Interference: dsinθ = mλ
- Destructive Interference: dsinθ = (m + 1/2)λ
Example: Calculating Path Difference and Interference in Young’s Experiment
Practical Applications of Diffraction and Interference

Applications of Diffraction

Diffraction in Daily Life
Examples of Diffraction Phenomena:
- Water Waves around a Pier
- Sound Waves through an Open Door
- Light Waves passing through a Small Opening
Diffraction as a Tool in Science and Technology

Applications of Diffraction (Contd.)

Diffraction in X-ray Crystallography
Using Diffraction Patterns for Molecular Analysis
Diffraction Grating in Spectroscopy
Medical Imaging and Diffraction
Conclusion: Importance of Diffraction in Various Fields

Summary

Recap of Key Points
Diffraction: Bending of waves around obstacles or through openings
Types of Diffraction: Single-Slit, Double-Slit, Diffraction Grating
Diffraction and Interference
Applications of Diffraction
Importance of Diffraction in Science and Technology

Slide 11

Diffraction - Diffraction at a straight edge

Definition of Diffraction at a straight edge
Explanation of how waves diffract when encountering a straight edge
Diffraction pattern produced by a straight edge
Diffraction angle and its relationship with the wavelength and size of the opening
Example: Calculating the diffraction angle for a given wavelength and opening size

Slide 12

Diffraction - Diffraction by a circular aperture

Diffraction by a circular aperture explained
Calculation of the first minimum for diffraction by a circular aperture
Airy disk pattern produced by a circular aperture
Relationship between the diameter of the aperture and the size of the central maximum
Example: Calculating the diameter of an aperture for a desired central maximum size

Slide 13

Diffraction - Diffraction limits of telescopes

Diffraction limit of a telescope defined
Explanation of how diffraction affects the resolution of telescopes
Relationship between the angular resolution and the wavelength of light
Equation for calculating the angular resolution of a telescope
Example: Calculating the angular resolution of a telescope given its aperture and wavelength of light

Slide 14

Diffraction - Single-slit diffraction and the width of the central maximum

Single-slit diffraction explained
Calculation of the width of the central maximum in a single-slit diffraction pattern
Relationship between the width of the central maximum and the slit width
Example: Calculating the width of the central maximum for a given slit width and wavelength

Slide 15

Diffraction - Resolving power of an optical instrument

Definition of resolving power in the context of optical instruments
Rayleigh’s criterion for resolving power
Equation for calculating the resolving power of an optical instrument
Relationship between the resolving power and the angular resolution
Example: Determining the resolving power of a microscope or telescope given their specifications

Slide 16

Diffraction - Polarization by diffraction

Polarization by diffraction explained
Relationship between the angle of polarization and the angle of diffraction for a polarized wave
Malus’s law applied to diffraction patterns
Example: Calculating the intensity of a polarized wave diffracted at a certain angle

Slide 17

Diffraction - Diffraction of X-rays

Diffraction of X-rays explained
Bragg’s law for X-ray diffraction
Relationship between the angle of incidence, the interplanar spacing, and the wavelength of X-rays
Application of X-ray diffraction in determining crystal structures
Example: Using Bragg’s law to calculate the interplanar spacing for a given angle of incidence and wavelength of X-rays

Slide 18

Diffraction - Grating equation for higher order maxima

Grating equation for higher order maxima explained
Calculation of the angle of diffraction for higher order maxima in a diffraction grating
Relationship between the order of the maxima, the wavelength, and the grating spacing
Example: Determining the angle of diffraction for the second or third order maxima in a diffraction grating given the wavelength and grating spacing

Slide 19

Diffraction - Diffraction efficiency of a grating

Diffraction efficiency of a grating defined
Factors affecting the diffraction efficiency of a grating
Calculation of the diffraction efficiency using the grating equation
Example: Calculating the diffraction efficiency for a given grating and incident angle

Slide 20

Diffraction - Diffraction of electron waves

Diffraction of electron waves explained
Similarities and differences between diffraction of electron waves and other types of waves
Relationship between the de Broglie wavelength, the momentum, and the diffraction angle for electron waves
Applications of electron wave diffraction in electron microscopy and diffraction spectroscopy
Example: Calculating the diffraction angle for a given de Broglie wavelength and electron momentum Diffraction - Diffraction at a straight edge
Definition of Diffraction at a straight edge
Explanation of how waves diffract when encountering a straight edge
Diffraction pattern produced by a straight edge
Diffraction angle and its relationship with the wavelength and size of the opening
Example: Calculating the diffraction angle for a given wavelength and opening size