Destructive Interference of Light in 165nm Bubble Film

In summary, the destructive interference of light waves in a bubble film with a thickness of 165 nm and an index of refraction of 1.3 can occur at wavelengths of 430 nm, 650 nm, 860 nm, and 285 nm. This is because the half-wavelength path difference is achieved when the light passes through the bubble film and is reflected from the inner surface, with the refractive index affecting the effective path length. The specific wavelength that causes destructive interference can be determined by multiplying or dividing the given refractive index by the wavelength options and comparing them to the problem's multiple choices.
  • #1
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Homework Statement



Light waves of which wavelength will destructively interfere due to the thickness of the bubble film? The bubble film thickness is 165 nm, with an index of refraction of n = 1.3.

a= 430 nm
b= 650 nm
c= 860 nm
d= 285 nm
(different wavelengths)

Homework Equations





The Attempt at a Solution



for the interference to be destructive the wave passing through the bubble thickness is delayed by half a wavelength. The wavelength of the light decreases when it passes into the bubble film.
I know this but i just don't know how to apply it to a equation and the problem
 
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  • #2
The half wavelength path difference corresponds to a light ray traversing the bubble film and being reflected from the inner bubble surface. So the path difference is twice the bubble thickness modulated by the effect of the refractive index. How does the refractive index alter the effective path length? Well you can try either multiplying or dividing by the given value of 1.3 to get the right mathematical result by comparison with the multiple choices; more important is to try to understand physically why light behaves like this in a transparent medium.
 
  • #3
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I would approach this problem by first understanding the concept of destructive interference. This occurs when two waves with the same frequency and amplitude are out of phase with each other, resulting in a cancellation of the wave amplitudes. In order for this to occur, the path difference between the two waves must be equal to an integer multiple of half the wavelength.

In this case, we are given the thickness of the bubble film (165 nm) and the index of refraction (1.3). We can use the equation nλ = d (where n is the index of refraction, λ is the wavelength, and d is the thickness of the film) to determine the wavelength of the light passing through the bubble film.

Substituting in the values, we can solve for the wavelength:

1.3λ = 165 nm

λ = 165 nm / 1.3

λ = 127 nm

This means that the wavelength of light passing through the bubble film is 127 nm. Now, we can compare this to the given wavelengths (a= 430 nm, b= 650 nm, c= 860 nm, d= 285 nm) to determine which will result in destructive interference.

Since the wavelength passing through the bubble film is significantly smaller than the given wavelengths, it is likely that all of these wavelengths will result in destructive interference. However, we cannot determine exactly which ones will without knowing the phase difference between the waves.

In conclusion, the destructive interference of light in a 165 nm bubble film will depend on the phase difference between the waves, but it is likely that all of the given wavelengths will result in destructive interference.
 

Related to Destructive Interference of Light in 165nm Bubble Film

1. How does destructive interference of light occur in 165nm bubble film?

Destructive interference of light occurs when two or more waves interact and their amplitudes cancel each other out. In the case of 165nm bubble film, this occurs when light waves pass through the film and interact with the air pockets within the film, causing the waves to cancel each other out and result in reduced or no light transmission.

2. What is the significance of 165nm in destructive interference of light in bubble film?

The size of the air pockets or bubbles in the film is crucial in causing destructive interference of light. At a size of 165nm, the bubbles are able to interact with the light waves in a way that results in significant interference, leading to reduced light transmission.

3. Can destructive interference of light be manipulated in 165nm bubble film?

Yes, the destructive interference of light in 165nm bubble film can be manipulated by changing the size, shape, and distribution of the bubbles in the film. This can be achieved through various manufacturing techniques, resulting in different levels of light transmission and opacity in the film.

4. How is 165nm bubble film used in practical applications?

165nm bubble film is commonly used in anti-glare and privacy filters for electronic devices such as smartphones, tablets, and laptops. It is also used in architectural and automotive window films to reduce glare and improve energy efficiency. Additionally, it can be used as a decorative material for packaging and signage.

5. Is destructive interference of light in 165nm bubble film reversible?

Yes, destructive interference of light in 165nm bubble film is reversible. When the film is removed from the light source, the bubbles will no longer interact with the light waves, and the interference will cease. This allows the film to be reused or repurposed for different applications.

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