TB Physical Optics & Lasers

Haidinger fringes: Fringes of equal inclination. Michelson interferometer, itsapplication for precision determination of wavelength, wavelength difference and thewidth of spectral lines. Twymann Green interferometer and its uses. Iriensity distributionin multiple beam interference, Tolansky fringes, Fabry-Perrot interferometer and etalon.
UNIT -IIFresnel diffraction: Fresnel half-period zones, plates, straight edge, rectilinearpropagation.Fraunhoffer diffraction: Diffraction at a slit, half-period zones, phasor diagram andintegral calculus methods, the intensity distribution, diffraction at a circular aperture anda circular disc, resolution of images, Rayleigh criterion, resolving power of telescope andmicroscopic systems, outline of phase contrast microscopy.Diffraction gratings: Diffraction at N parallel slits, intensity distribution, planediffraction grating, reflection grating and blazed gratings. Concave grating and differentmountings. Resolving power of a grating and comparison with resolving powers of prismand of a Fabry-Perrot etalon.
UNIT - IIIPolarization, Double refraction in uniaxial crystals, Nicol prism, polaroids andretardation plates, Babinet's compensator. Analysis of polarised light. Optical activityand Fresnel's explanation, Half shade and Biquartz polarirneters.Matrix representation of plane polarized waves, matrices for polarizers, retardationplates and rotators, Application to simple systems.
UNIT-IVLaser system: Purity of a special line, coherence length and coherence time, spatialcoherence of a source, Einstein's A and B coefficients, spontaneous and inducedemissions, conditions for laser action, population inversion.Application of Lasers: Pulsed lasers and tunable lasers, spatial coherence anddirectionality, estimates of beam intensity; temporal coherence and spectral energydensity.