Optics and Spectroscopy - III Semester 2021-2022 Syllabus for II Year Physics
II YEAR – III SEMESTER
COURSE CODE : 7BPH3C1
CORE COURSE VI – OPTICS AND SPECTROSCOPY
Unit I GEOMETRICAL OPTICS
Lens – Spherical aberration in lenses – Methods of minimizing spherical aberration – chromatic aberration in lenses – condition for achromatism of two thin lenses (in and out of contact) – Coma - Aplanatic lens – Eyepieces – Ramsden’s and Huygens’s eyepieces.
Dispersion – Angular and Chromatic dispersion – combination of prisms to produce i)dispersion without deviation ii) deviation without dispersion – Cauchy’s dispersion formula– Direct vision spectroscope – Theory of formation of rainbow.
Unit II INTERFERENCE
Conditions for interference – colours of thin films – Air wedge – theory – determination of diameter of a thin wire by Air wedge – test for optical flatness – Newton’s rings – Determination of refractive index of a liquid.
Michelson’s Interferometer – theory and its Application (Measurement of wavelength and difference between wavelength of two close lines, thickness of mica sheet) – Jamin’s interferometer – determination of refractive index of gases
Unit III DIFFRACTION
Fresnel’s diffraction –Rectilinear propagation of light – zone plate –diffraction at circular aperture – opaque circular disc – Fraunhofer diffraction at single slit – Double slit – Plane diffraction grating – theory and experiment to determine wavelength – overlapping of spectral lines.
Rayleigh’s criterion for resolution – resolving power – resolving power of grating – resolving power of a prism
Unit IV POLARIZATION
Double refraction – Huygens’s explanation of double refraction in uni axial crystals – Nicol Prism – Nicol Prism as polarizer and analyzer – Polaroids and their uses – Quarter wave plates and Half wave plates. Plane, elliptically and circularly polarized light – Production and detection
Optical activity– Fresnel’s explanation of optical activity – Specific rotatory power – determination using Laurent’s half shade polarimeter
Unit V SPECTROSCOPY
Microwave and infrared Spectroscopy – Rotation of molecules – Rotational Spectra – The rigid diatomic molecules, selection rules – the intensities of spectral lines – Infrared spectroscopy (outlines only)
Raman Spectroscopy – Quantum theory of Raman effect – Classical theory of Raman effect – Molecular Polarisability – pure rotational Raman spectra of linear molecules – vibrational Raman spectra – Applications.
Text Books:
- Optics and Spectroscopy – R.Murugeshan, S. Chand and co., 6th Edition, New Delhi, 2008.
- A text book of Optics – Subramanyam and Brijlal, S. Chand and co., 22nd Edition, New Delhi 2004.
- Elements of Spectroscopy – S.L. Gupta, V.Kumar and R.C.Sharma Pragati Prakashan, 13th Edition, Meerut, 1997
Books for Reference:
- Optics – Sathyaprakash, Ratan Prakashan Mandhir, VIIth Edition, New Delhi, 1990.
- Introduction to Molecular Spectroscopy –C.N.Banewell,TMH publishing co. IV Edition, New Delhi, 2006.
- Molecular structure and spectroscopy – G.Aruldhass, PHI Pvt Ltd, , II Edition, New Delhi, 2007.
Differences Between Normal and Anomalous Zeeman Effect
Normal vs Anomalous Zeeman Effect | |
| The splitting of a spectral line of an atom into three lines in an external magnetic field is called normal Zeeman effect. | The splitting of a spectral line of an atom into four or more line in the presence of a magnetic field is called anomalous Zeeman effect. |
| This can be explained on the basis of classical physics. | This can only be understood on the basis of quantum mechanics invoking electron spin. |
| Magnetic moment is due to orbital angular momentum. | Magnetic moment is due to both orbital and nonzero spin angular momentum |
| Involves transitions between singlet states. | Involves transitions between doublet, triplet etc states |
| Calcium, copper, zinc, and cadmium are some elements that show this effect. | Sodium and chromium are two elements that show this effect. |