2POLARISED LIGHT MICROSCOPE Designed to observe optically anisotropic specimen (BIREFRINGENCE SPECIMEN)Equipped with POLARISER and ANALYZERWorks on the principle of INTERFERENCE
3COMPONENTS OF POLARISED LIGHT MICROSCOPE AND THEIR FUNCTION EYEPIECEOBSERVATION TUBEBERTRAND LENSANALYSERRETARDATION PLATE (COMPENSATOR)GRADUATED CIRCULAR ROTATING STAGELIGHT SOURCEPOLARISER
4FUNCTION EYEPIECE BERTRAND LENS Eyepieces are fitted with a cross wire reticle to mark the center of the field of view.Orientation of the eyepiece with respect to the polarizer and analyzer is guaranteed by a point that slides into the observation tube sleeveBERTRAND LENSIt is a specialized lens mounted within the observation tube.Projects an interference pattern formed at objective rear focal plane in focus at the microscope image plane.Is designed to allow accurate adjustment of the illuminating aperture diaphragm and to see interference figures.
5RETARDATION PLATE (COMPENSATOR) These are inserted between the cross polarizers.Enhances the optical path difference in the specimen.GRADUATED CIRCULAR ROTATING STAGEIt is a 360 degree rotating specimen stage.Facilitates the orientation studies with centration of the objective and stage with microscope optical axis.It contains the Vernier scale to measure the degree of rotation of the specimen with accuracy of 0.1 degree.
6FUNCTION OF MAJOR COMPONENTS BIREFRINGENT SPECIMENBirefringence is an optical property of a material having a refractive index that depends on the polarization and propagation direction of light.Birefringent materials have different indices of refraction for light polarized parallel or perpendicular to the optical axis.Two beams with orthogonal polarization are produced if illumination is at an angle to optical axisDepending upon the orientation of the specimen, colour of the image changes
7POLARIZER AND ANALYZER POLARIZER confines white light to vibrate in one plane when light passes through it .The birefringent specimen breaks the polarized light into two components viz. ordinary and extra ordinary light.These two components of light when passes through ANALYZER, INTERFERENCE occurs by virtue of which image obtained is colourful .
8DIFFERENCE BETWEEN SIMPLE MICROSCOPE AND POLARISED LIGHT MICROSCOPE SIMPLE LIGHT MICROSCOPEIt has polarizer and analyzer.An optically anisotropic specimen called birefringent specimen is used.Works on the principle of interference.Colourful image is obtained due to interference.It does not have these two components.Any specimen can be used.Works on the principle of reflection and refraction.Color of the image obtained is same as that of the specimen.
10FACTORS AFFECTING THE COLOR OF IMAGE Orientation of the specimen.Thickness of the specimen.Path difference between the ordinary and extra ordinary light rays.Orientation of the polarizer and analyzer with respect to each other.