Conceptual Question about Polarisation and Intensity/

In summary, the problem involves a beam of unpolarised light incident onto air from crown-glass with a refractive index of 1.52. The incident light has an intensity of 10mW and the goal is to find the minimum incident angle at which the power of the refracted light becomes zero. The equations to solve this are unknown, but it is known that the incident angle must be Brewster's Angle for the light to become fully polarised. The second part of the question involves finding the polarisation state of the reflected light. The solution was found to be 56.7 degrees for Brewster's Angle and Linear Polarisation for the reflected light.
  • #1
JohnGaltis
18
0

Homework Statement


Consider a beam of unpolarised light incident onto air from a crown-glass with a refractive index of 1.52.

Given that the incident light intensity has a power of 10mW, find the minimum incident angle when the power of the refracted light becomes zero.

Homework Equations


I have no idea what equations can be used to solve this.

The Attempt at a Solution


From what I understand, the unpolarised light can lead to a reflected polarised beam and a refracted beam- this happens if the angle of incident is Brewster's Angle.

I am guessing the power of the refracted light is zero if the reflected light is fully polarised?
 
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  • #2
This is the second part of the question. First part asked for Brewster's Angle and the polarisation state(56.7degrees and Linear Polarisation)
 
  • #3
Hey John, you mind to show the steps done?

Update: It's alright I figured it out. :)
 
Last edited:

1. What is polarisation and how does it affect light?

Polarisation is the orientation of the electric field of a light wave. It refers to the direction in which the electric field oscillates. When light is polarised, the electric field oscillates in a specific direction, resulting in a specific orientation of the light wave. This can affect how the light is transmitted, reflected, or absorbed by different materials.

2. How is polarisation different from intensity?

Polarisation and intensity are two different characteristics of light. Polarisation refers to the orientation of the electric field, while intensity refers to the brightness or strength of the light. Polarisation does not affect the intensity of light, but it can affect how the light is perceived by our eyes or how it interacts with certain materials.

3. What is the relationship between polarisation and the angle of incident light?

The angle of incident light can affect the degree of polarisation of that light. When light is incident at a perpendicular angle, it is fully polarised, meaning the electric field oscillates in only one direction. As the angle of incidence deviates from the perpendicular, the degree of polarisation decreases until it becomes unpolarised at a grazing angle of incidence.

4. Can polarisation be observed with human eyes?

No, polarisation cannot be observed with the human eye. Our eyes are only sensitive to the intensity and color of light, not its polarisation. However, we can use polarising filters or special glasses to block or enhance certain polarisation orientations, allowing us to see the effects of polarisation on light.

5. How is polarisation used in technology and everyday life?

Polarisation has many practical applications in technology and everyday life. It is used in LCD screens, sunglasses, and 3D glasses to control the orientation of light and reduce glare. It is also used in communication systems, such as satellite transmissions, to reduce interference. In everyday life, polarisation is used in photography to enhance contrast and reduce reflections, and in materials like polarised windows to reduce heat and glare.

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