Light is central to human perception. Light from all directions bombards our eyes, and our brain constructs images of objects by processing this information. As a consequence, we perceive shapes, textures, colours and motion of objects. The play of early morning sunlight on the snowcaps of mountains, the left-handed image of a mirror, the colour of crystals or the distorted view of objects under water has revealed to us deep secrets of nature. This is, perhaps, why the study of light, the phenomena associated with it, and its interaction with matter has engaged human mind for over three thousand years.
While reflecting upon the developments in the study of light today, we have chosen the most interesting and relevant themes. In this course on optics, IGNOU presents the generic themes like nature of light, perception of light, interference and diffraction, apart from the Iatest developments in optical technology, such as lasers, holography and fibre optics.
Syllabus per Block Divisions in IGNOU BSc Physics -Optics PHE-09
Block 1: Introducing Light
- Unit 1: Nature of Light
- Unit 2: Reflection and Refraction of Light
- Unit 3: Perception of Light
- Unit 4: Polarisation of Light
Block 2: Interference
- Unit 5: Interference by Division of Wavefront
- Unit 6: Interference by Division of Amplitude
- Unit 7: Interferometry
Block 3: Diffraction
- Unit 8: Fresnel Diffraction
- Unit 9: Fraunhoffer Diffraction
- Unit 10: Diffraction Gratings
- Unit 11: Diffraction and Resolution
Block 4: Lasers and their Applications
- Unit 12: Coherence
- Unit 13: Physics of Lasers
- Unit 14: Holography
- Unit 15: Fibre Optics
Detailed Syllabus for IGNOU BSc Physics -Optics PHE-09
Electromagnetic Nature of light, Wave Equation, The Poynting Vector; Reflection and Refraction of Electromagnetic waves, Normal and Oblique Incidence, Fresnel’s Relations; Idealization of Waves as Light Rays; Fermat's Principle; Human Vision, Image Formation and Processing; Defects of Vision; Colour Vision; Colour Receptors.
Polarisation of Light, Production of Linearly Polarised Light, Polarization by Reflection, Brewster's Angle; Malus Law; Birefringence and Production of Polarized Light, Nicol Prism, Dichroism, Wave Plates.
Principle of Superposition of Waves; Young's Experiment, Fringe Width, Intensity Distribution; Interference with White Light, Fresnel's Biprism and Lloyd's Single Mirror; Interference by Division of Amplitude, Phase Change on Reflection, Interference with Multiple Reflection, Non-reflecting Films and Colour of Thin films; Fringes of Equal Thickness and Equal Inclination; Newton's Rings; Michelson Interferometer: Circular and Localised Fringes; White Light Fringes; Fabry-Perot Interferometer.
Fresnel's Diffraction: Fresnel's construction, Fresnel’s Half Period Zones, Zone Plate; Diffraction Patterns of Simple Obstacles; Fraunhofer’s Single Slit Diffraction Pattern, Intensity Distribution; Diffraction by a Circular Aperture and Double Slit, Intensity Distribution, Position of Maxima, Missing Orders; Diffraction by N-Parallel and Identical Slits: Principal and Secondary Maxima; Diffraction Grating, Formation of Spectra; Diffraction and Image Formation, Diffraction limited systems, Resolution, Resolving Power of Optical Instruments; Michelson Stellar Interferometer.
Coherence and Observable Interference of Waves, Temporal Coherence, Coherence Time and Coherence Length, Width of a Spectral Line, Spatial Coherence, Lateral Coherence Width, Angular Diameter of Stars; Visibility of Fringes.
Emission and Absorption of Light, Stimulated Emission, Einstein's Relations, Population Inversion; Optical Pumping; Intensity of Light; Different Pumping Mechanisms; Three and Four Level Pumping Schemes; Feedback Mechanism: Optical Resonant Cavity, Common Laser Systems, Solid State, Liquid and Helium-Neon Lasers, Applications of Lasers in Communication, Medicine, Industry, and Photography.
Basic Principle of Holography; Recording of a Hologram, In-Line and Off-Axis Hologram, Reconstruction of an Image; Recording and Reconstruction of Hologram; Applications of Holography: Microscopy, Information Storage, and Pattern Recognition.
Optical Fibre, Core and Cladding Materials and Their Refractive Indices; Propagation of Light Through Optical Fibre, Critical Angle; Step-Index Fibre, Gradient-Index Fibre, Refractive Index Profiles; Applications of Optical Fibres, Optical Communication Through Fibres, Pulse Dispersion and its Reduction, Material Dispersion, Power Loss.