explain how can polarised light be experimentally detected
Answers
polarisation of light can be detected by using Nicol prism.
well, basically there are three type of polarised light possible.
1. plane polarised light
2. circular polarised light
3. elliptical polarised light.
detection of Plane Polarised Light : the beam of light is allowed to fall on Nicol prism. when rotation of Nicol prism, intensity of emitted light can be completely extinguished at two places in each rotation, then light is plane polarised.
detection of circularly polarised light: the beam of light is allowed to fall on a Nicol prism.when rotation of Nicol prism, the intensity of emitted light remains same, then light is either circularly polarised or unpolarised. To differentiate between unpolarised and circularly polarised light, first of all, the light is passed through quarter wave plate and then through Nicol prism. Because if beam is circularly polarised then after passing through quarter wave-plate an extra difference of λ/ 4 is introduced between ordinary and extraordinary component and gets converted into plane polarised. Thus on rotating the Nicol, the light can be extinguished at two plates.
detection of elliptically polarised light : The beam of light is allowed to fall on Nicol prism. when rotation of Nicol prism, the intensity of emitted light varies from maximum to minimum, then light is either elliptically polarised or a mixture of plane polarized and unpolarized light . To differentiate between them, firstly light is passed through quarter wave plate and then through Nicol prism. Because, if beam is elliptically polarised, then after passing through quarter wave plate, an extra path difference of λ/ 4 is introduced between 0-ray and E-ray and get converted into plane polarized.
