Change in the direction of propagation of a wave when its transmitting medium changes.

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13
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4answers
1k views

Looking for the actual reason of refraction explained precisely without analogies

I'm a high school teacher trying to teach my students (15year olds) about refraction. I've seen a lot of good analogies to explain why the light changes direction, like the marching band analogy, that ...
2
votes
1answer
69 views

Wave equation in varying mediums

I recently stumbled upon the above image describing partial transmittance, and was wondering what sort of equation would model such a wave propagating through varying mediums. Is there also an ...
0
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3answers
208 views

Refraction through prism

We know that the light gets refracted when it enter a medium low/high refractive index. But why light is not refracted when it comes out from the vertex of a prism.
3
votes
1answer
211 views

Is there a way to increase the speed of light itself?

When light enters materials it slows down due to its refractive index (due to absorbing and re-emission of photons). But, is there a way to increase the speed of light itself? Can there be some ...
1
vote
1answer
931 views

What causes refraction of visible light? [duplicate]

Refraction is the bending of a wave when it enters a medium where its speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the ...
0
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0answers
10 views

Refractive Index of Super Critical Fluids

I'm studying optics at the moment and I am wondering how the refractive index changes when a liquid is in super critical state? Thank you.
1
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1answer
87 views

Polarization in Nicol prism

My book reads "When unpolarized light is incident on nicol prism (made of 2 crystals joined by Canada balsam a type of glue) it divides into 2 rays, both rays are plane polarized and electric field ...
1
vote
1answer
65 views

Question about the refraction of Fresnel lenses

If you line up the suns rays parallel to a Fresnel lens, the light is concentrated, and the focus directly underneath. However, what happens if the sun is off to the side, making the light hit at an ...
5
votes
3answers
4k views

Real and imaginary parts of dielectric constant vs refractive index?

So for a complex dielectric constant $\epsilon = \epsilon_a + i\epsilon_b$, the wave vector and index of refraction are related to it through $k = \frac{\omega}{c}n$ and $n = \sqrt{\frac{\mu ...
1
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1answer
217 views

Finding out the minimum deviation angle [duplicate]

Let a light incident on a prisom at right angle. I want to determine the minimum deviation angle. I know a relation $$ \frac{\cos i_1}{\cos r_1} = \frac{\sin i_1}{\sin r_1}$$ and minimum angle ...
4
votes
3answers
74 views

Why don't fogbows appear on clouds?

As far as I know clouds are lot of small droplets condensed in air. If droplets are large enough we see a rainbow. If they are small we see a fogbow. Although the size of the droplets are big enough ...
0
votes
3answers
141 views

Is light slower when traveling inside a gravity field?

This question is not about phase velocity changed which causes refraction, but about the real time itself being slower by the gravity of any object (from general relativity). If so, would this mean ...
1
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2answers
61 views

Temperature-induced wavelength shift of optical coatings?

Optical coatings designed for reflection or anti-reflection are made of many thin layers which will expand when heated. What will the effect be on the wavelengths the coating will reflect when the ...
5
votes
2answers
797 views

Is there a theoretical maximum for refractive index?

May there be materials yet to be discovered which may have a higher refractive index than today's known materials (for wavelengths within the visible range)? Is there a theoretical limit for the ...
8
votes
2answers
420 views

Do photons age in a medium?

According to special relativity, time starts to slow down as we increase our speed and eventually stops once we get to the speed of light. By that logic, photons don't age in a vacuum state as, to us, ...
0
votes
1answer
117 views

Dispersion relation of silicon

In the case of dispersion relation of silicon having crystal plane orientation 111; what is the Sellmeier's equation for refractive index $n$ of silicon orientation 111 & what it's extinction ...
-2
votes
4answers
396 views

Why is the speed of light considered as a fundamental constant if its speed changes with medium resulting in refraction? [duplicate]

I know that the speed of light, the universal constant of gravitation and the Planck's constant are considered to be the three fundamental constants of the universe. But, why is speed of light ...
3
votes
1answer
528 views

Why would an object appear a different size when in water?

A friend of mine has a homework question and we're having some trouble figuring out what physical mechanisms come into play for this. An underwater swimmer sees a spherical air bubble that appears ...
1
vote
2answers
170 views

Refraction of light in medium

Given that the plane $y=0$ separates the vacuum ($y>0$) from the optical medium ($y<0$), I would like to calculate the trajectory of a light ray starting at the point $(x_1,y_1)$ and ending in ...
2
votes
1answer
2k views

Analytic solution for angle of minimum deviation?

Consider a simple prism with a prism angle $A$, angle of incidence $\theta_1$, angle of emergence $\theta_4$ and the first and second angle of refraction as $\theta_2,\theta_3$. the refractive index ...
4
votes
1answer
194 views

Anisotropic refractive index with isotropic components?

In relation to my question here I wanted to make sure that my physical argument was not flawed. Anisotropic properties, (especially refractive index) is characteristic of a well-ordered solid ...
4
votes
3answers
670 views

Real image with converging lens?

I read in a AQA GCSE book that: A real image is formed by the converging lens if the object is further away from the principal focus/focal point. I did this experiment in class: Here is my ...
2
votes
3answers
142 views

Law of refraction from Scalar Diffraction Theory

I am trying to figure out if Snell's Law for refraction can be derived from Scalar Diffraction Theory. The setup is this: light (plane wave, with wave vector $\vec k_i = (k_x, k_y, k_z)$ ) falls on ...
5
votes
1answer
221 views

Why Negative refractive index is negative

$n=\sqrt{\epsilon \mu }$ Negative refractive index happens when permittivity ($\epsilon $) and permeability ($\mu $)of a material is negative. My question is, if permittivity and permeabilitity of a ...
1
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2answers
140 views

Good explanation of a real image?

Okay well I've started to study phys chem in school recently and I honestly can't get my head around what a real image actually is I've asked my teacher to demonstrated it but she's quite lazy, and ...
4
votes
1answer
362 views

Why does the light at the bottom of the pool form this awesome pattern?

Take a look at the following picture: Why does the light at the bottom of the water form this pattern? I have also seen the same phenomenon in all the swimming pools I've ever visited, of whatever ...
2
votes
1answer
262 views

Faster than light in plasma

Some plasmas have a refraction index of less than 1. In these plasmas the phase velocity of light can be faster than light-speed. But the phase itself won't transfer information, so no paradox occurs ...
1
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0answers
130 views

If a beam of light follows the path $y(x)=y_0\sin(x/y_0)$, what is the index of refraction?

An exam question that showed up while I was studying: A plane wave refracts and follows a ray given by the equation $y=y_0\sin(x/y_0)$ where $y_0$ is a constant. Find the refractive index $n(y)$ ...
1
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2answers
248 views

Calculate the polarization vector on reflection or refraction from a dielectric interface

I am interested in ray-tracing polarized photons. I have code that works very well for unpolarized light. When a ray hits a dielectric interface the photon is either reflected or refracted by ...
2
votes
1answer
210 views

Why does a mirage disappear as you approach it?

Related: why do mirages only appear on hot day? The title says it all: why does a mirage disappear as you approach it? The related question does not answer this.
2
votes
3answers
345 views

Problem on apparent height of postage stamp underneath paperweight

A postage stamp is placed on a surface and a glass cube of refractive index $1.5$ is placed over it. When observed through the cube, the stamp appears at a height of $1.5cm$ from the bottom of the ...
2
votes
2answers
178 views

How far can you scatter light using a prism?

If I were to scatter light how far do you think it will disperse and what prism is the most effectively scatters light?
1
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1answer
38 views

Full refraction in fibre optics

Well in a problem I had to calculate the maximum amount of "reflections" in a glass fibre optic pipe (index of refraction = 1.3, width of 20 micrometer and length of 1 meter). I am a bit blocked on ...
4
votes
2answers
246 views

Shape of the rainbow

I have watched Walter Lewin's lecture(http://www.youtube.com/watch?v=6QVbE_tU2sA) which was about the rainbows. But there is still a question bothering me. I understood the first part of the ...
2
votes
1answer
226 views

Refraction of light in water

Here's a question in a paper based on refraction of light. I can't seem to solve it for some reason. A man looks down at a fish length of 20 cm. His eye is 2m above the surface of the water ...
6
votes
1answer
767 views

How does sun light after it has passed window's pane still heat me up?

I believe it is so because most of photons' energy has successfully passed the glass. But is it so? And how can I roughly estimate part of light's energy which will pass obstacles like glass? And how ...
5
votes
1answer
2k views

Why do some materials reflect (metals) and other materials reflect and refract (glass) from the quantum perspective?

Recently I was asked to explain the difference between reflection and total internal reflection from a purely conceptual standpoint (no math). Let me explain what I already know. Reflection and ...
3
votes
2answers
288 views

Photons-Wave/particle duality

I know that photons and electrons and such are said to have a wave particle duality, but what does that mean for a photon? When light strikes an object, are many photons emitted, enough to draw ...
1
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2answers
2k views

Effective Refractive Index

Can some one please explain in simple words that what is effective refractive index? How it is different from the refractive index? And how we can calculate the effective refractive index?
2
votes
3answers
300 views

How Does $\epsilon$ Relate to the Dampened Harmonic Motion of Electrons?

I realize that the permittivity $\epsilon$ of a substance is easily calculated based on diffraction angles, but I am not satisfied with merely measuring it experimentally. I wish to understand its ...
2
votes
3answers
602 views

Two different mediums can have equal index of refraction?

In other words: given a certain medium, is light's phase velocity unique?
1
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2answers
751 views

What makes radio waves refract?

What materials cause radio waves to refract? What are the radio IOR's of these materials?
2
votes
1answer
260 views

Reflections in a glass of water

I've noticed that if you take a full glass of water and look from above, through the water, you can't see through the glass sides - instead, you see a reflection. I tried with a laser pointer and the ...
1
vote
1answer
252 views

Simple Question: Speed of Electromagnetic Waves in a Medium

If the speed of an electromagnetic wave in a particular medium is such that $v = c$, the speed of light, does this mean that the permeability $\mu = \mu_0$, i.e. that of a vacuum and the index of ...
2
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1answer
136 views

Perfectly focusing refractive surface

On reading Feynman's lecture on physics, in the geometrical optics section he said that a curve which focuses all the rays coming from a point to another fixed point beyond the refracting surface ...
22
votes
4answers
3k views

Why do prisms work (why is refraction frequency dependent)?

It is well known that a prism can "split light" by separating different frequencies of light: Many sources state that the reason this happens is that the index of refraction is different for ...
1
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2answers
698 views

Refraction of light and frequency dependence

Why do higher frequency waves refract more, both ocean waves and light waves? Also why is energy stored in the frequency as opposed to the wavelength.
2
votes
2answers
124 views

Penetration of light in the atmosphere

While I was considering an answer to this question, I wondered how much light that enters the atmosphere reaches the ground without colliding with air molecules—if any. I've taken a good bit of ...
2
votes
1answer
129 views

Relation of color and frequency for the visible spectrum

In this question the OP is looking for a way to see light that is outside of the visible spectrum without using electronic sensors. This got me wondering about the visible spectrum itself. Typically ...
1
vote
1answer
770 views

Apparent and real depth object in water [closed]

Did I get my formula right? Seems like the correct answer is $d_o = 1.33 \times d_i$ but I thought the formula I should use is $d_i = - \frac{n_2}{n_1} d_o$