L09 Polarisation

Question 1

polarised light

Answer 1

Transverse wave motion in only one direction

Question 2

Unpolarised light

Answer 2

Mixture of waves vibrating in all planes

Question 3

Name 4 different polarisation method

Answer 3

Naturally - reflection, scattering

Artificially - transmission, refraction

Question 4

Polarisation by reflection

Answer 4

When reflected wave is perpendicular to refracted wave, light that is specularly reflected is plane-polarised in the plane of surface

Question 5

Brewster’s angle

Answer 5

Incident angle that causes plane-polarisation

Question 6

Formula of brewster’s angle

Answer 6

Tan o = n2 / n1

Question 7

Polarisation by scattering

Answer 7

Occurs when light hits non-homogenous material and scatters.it results in scattered light to become either completely or partially polarised . Scattered light perpendicular to incident light is completely polarised

Question 8

Polarisation by transmission

Answer 8

Results from having conducting material consisting of fine grid arranged either vertically or horizontally
Light traveling parallel to the absorption axis is absorbed. Light travelling parallel to the transmission axis is transmitted as polarised light

Question 9

Calcite crystal

Answer 9

• Anisotropic where material has different structure in different direction
• Results in different refractive index and absorption strength in different direction
• Different polarisation component travels at different speed

Question 10

Polarisation by refraction

Answer 10

• Occurs when light passes through an anisotropic material
• Results in different refractive index and absorption strength in different directions
• Different polarisation component travels at different speed