Optics is the study of light, and its interaction with matter. It includes topics such as imaging systems, fiber optics, lasers, quantum optics, and more.

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Why does shining a laser into an iPhone camera create these shapes?

When I shine a laser light into an iPhone 6 camera I get these weird shapes: The shapes are in no way in the background behind the laser. What causes these to appear? I know about typical lense ...
2
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1answer
163 views

Interference of LED Lights

I have read that colored LED lights are nearly monochromatic. Does this mean that they could be used in double slit interference?
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2answers
6k views

Why are gold mirrors yellow?

Why are golden mirrors yellow? Do they add a yellow component to the spectrum or absorb non-yellow components? If they absorb, then why are they used in telescopes being imperfect? If they add a ...
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2answers
260 views

Is it possible to calculate the dimensions of ANY object in a picture having at some known distance an object on know dimensions?

Is it possible to calculate the dimensions of ANY object in a picture having at some known distance an object on know dimensions? I'm thinking about the scenario where someone is holding a smartphone ...
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0answers
27 views

Converging rail tracks

When we look at parallel rail tracks, it appears to converge at a certain angle. Let us say the width of the tracks is d and the height of the eye is h. Assuming one stands in the middle of the tracks,...
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0answers
29 views

Lens-Mirror systems and conservation of specific intensity

This came out of a discussion I started yesterday and a related discussion I found. I'll recap the problem quickly: Consider two blackbodies, with surface areas $A_1$ and $A_2$ and temperatures $T_1$ ...
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34 views

Thickness of glass sheet with Michelson's interferometer

I've got a question, are we able to calculate the thickness of a glass sheet by using Michelson interferometer experiment ?
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1answer
898 views

Way of measuring thickness of a glass [closed]

Imagine you have a laser pointer and a glass. You don't know the refractive index of the glass and you just have Wavelength of laser! How can you measure the thickness of glass? (I have some idea but ...
2
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2answers
129 views

Appartus for Young's double slit?

I am wanting a full description of an apparatus used for Young's double slit (not necessarily the one that Young himself used though), which takes monochromatic light (though not laser light) and ...
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2answers
118 views

Video of light passing through water

How is this possible? https://www.youtube.com/watch?v=EtsXgODHMWk Video shows beam of light travelling through water. I was under impression that Einstein's equations showed that light speed is ...
2
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1answer
240 views

Why does circularly polarized light break time-reversal symmetry?

I've encountered some interesting paper on 2D materials where authors use circularly polarized light to break time-reversal symmetry to split energy levels. Here you can find the paper: Valley-...
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0answers
16 views

What is micropulsing in optics?

I've seen this in a presentation, but I am not quite sure what it means. Is it simply emitting light in a sequence of very short pulses?
2
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2answers
166 views

What is really a light ray? [duplicate]

I've been studying geometric optics and I'm still a little confused with this idea of light ray. In the book I'm studying everything is being done starting from Fermat's principle which states that ...
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5answers
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If a lens focuses all incoming light to a point, how do we get 2D images?

How do lenses produce 2-dimensional images, if a lens bends all incoming rays of light to intersect at the focal point? Shouldn't this produce a single dot of light on a screen placed at the focal ...
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3answers
3k views

Calculating light's lateral shift in a glass slab

I have tried to compute light's lateral shift after passing through a glass slab In terms of the incidence angle $\theta_1$, the slab thickness $d$ and the refraction index $n$, I have found that ...
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2answers
103 views

How can one prove the equation for a system of lenses? [closed]

Let's say we have a system of 2 lenses which are placed in a non-negligible distance $L$ from eachother. How can I prove without using geometrical construction and principal planes that $$\frac 1f =...
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0answers
15 views

Optics Simulation Software for Airy Beam Generation [duplicate]

I have been trying to simulate the generation of Airy Beams using a simple two-cylindrical lens setup as shown by Papazoglou et al. http://journals.aps.org/pra/abstract/10.1103/PhysRevA.81.061807 I ...
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1answer
81 views

In geometric optics we treat light as a collection of particles?

I've been reading the book "Geometric Mechancis" by Darryl Holm and the in the first chapter he treats geometric optics. There the author talks about light rays and those light rays looks like ...
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1answer
34 views

What blurs the swimming pool

Mystery of the swimming pool With eyes above water, I can see the bottom of the pool very clearly, almost as if the water wasn't there. Refraction at the water level shifts the grout lines between ...
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2answers
108 views

thin film interference of light

In a thin film interference (reflective system) I know that condition for maxima is $$2\mu t\cos(r)=(2n\pm 1)\frac{\lambda}{2}$$ and for minima is $$2\mu t\cos(r)=n\lambda$$ and for transitive system ...
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1answer
67 views

Laser: Looking for name for optical component

I'm currently planning a laser setup in which I want to send a (1mW) laser into the environment using a commercial scanning unit (made of two galvanometers). I would like to measure the reflectivity ...
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0answers
28 views

Optical path length and extremum time taken in Fermat's principle [duplicate]

Could someone please explain what is meant by stationary optical path length and extremum time taken in Fermat's principle?
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1answer
737 views

Question about lens maker's formula

I am trying to follow the derivation of lens maker's formula from the textbook "University Physics", p.1133 (https://books.google.com.hk/books?id=nQZyAgAAQBAJ&pg=PA1133#v=onepage&q&f=false)...
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2answers
76 views

How to estimate if an image is in focus

I am building a test measurement (optics) to look a rectangular slit opening (1mm x 15 microns). The slit opening is illuminated by a white LED and using a microscope objective to magnify it to 10X on ...
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1answer
69 views

Transmission of light, sub-wavelength apertures, and cut-off frequencies

I was hoping someone could please explain how the transmission of light through a sub-wavelength aperture in a metal film, at a particular wavelength, changes when the aperture is: i) above cut-off ...
2
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1answer
191 views

Refraction of white light through a glass slab: what does it actually look like?

When a collimated beam of white light enters a rectangular prism, it develops slightly coloured edges due to the dispersive refraction of the glass: each ray in the beam is displaced differently ...
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1answer
78 views

Does the order in which light comes into a rectangular prism affect its dispersion?

I read about how when light comes out of a rectangular prism, there are violet and red fringes on either side of the light spectrum. The website didn't give the specifics in this subject, so I am not ...
2
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1answer
138 views

Maxwell Stress Tensor at material boundaries

I am trying to grasp the meaning of the Maxwell Stress tensor $T_i^j$ at material boundaries. Concretely, I am trying to calculate the force between two waveguides. The results are given in an article ...
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1answer
89 views

Why, in Chroma key composting, green colour is used? [closed]

In movie shootings, we observe that the Chroma Key Composting method is used very widely. Why do they only use dark green colour, what not some other like white, blue etc,
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0answers
45 views

How to design a grating coupler to produce surface plasmon-polaritons (SPPs) at a desired frequency?

Following on from this question, which I found very useful on the topic, I was wondering how you would use the equation $\beta = k sin \theta \pm \nu g$ to fabricate a grating coupler to generate SPPs ...
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0answers
57 views

How to apply contrast sensitivity function to an image?

I would like to apply contrast sensitivity function (CSF) to an image. My idea is to do the Fourier tranform of the image and then do the filtering in the frequency domain by applying the CSF. However ...
3
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1answer
113 views

Can someone please explain extraordinary optical transmission (EOT)?

Can someone please explain extraordinary optical transmission (EOT)? I'm hoping someone can describe the physical process by which light is transmitted through a periodic metal hole array which is ...
2
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2answers
132 views

How light splits up into different colours when passed through prism using QED?

I want to know how light gets splits up into different colours when it is passed through prism? How light interacts with atoms and electrons of the prism? Can someone explain this to me using Quantum ...
3
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1answer
123 views

Mechanism for visible light frequency mixing in storm clouds

So I know that when red and blue light (or the frequencies/wavelengths we percieve as such) hit our eyes with the correct proportions, our eyes and brains interpret that as the color purple. In ...
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2answers
146 views

Is circular masking a laser beam an acceptable way to get the beam diameter you require?

I am wondering what are the down sides to just masking a laser to get the beam diameter you require? For example if you have a collimated eliptical beam of say 2mm width and 4mm height, but you ...
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1answer
37 views

Blazed phase profile to generate laguerre gaussian beam

How to add blazed grating to a fork grating to achieve maximum diffraction efficiency in the first order while generating laguerre gaussian beam?
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1answer
289 views

Is the formula, for finding the distance between two slits, my books gives correct?

In my book'a section on Young's double-slit experiment, the formula, $d = m \lambda \sin\theta$, is given. In this equation $d$ is the distance between two slits, $\lambda$ is the wavelength of light ...
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1answer
127 views

Is this diagram, concerning Young's double slits, inaccurate?

"This diagram" : My question is whether those lines (interference) have to originate from a single point. The diagram used to demonstrate what $m$ (path difference) means, has two lines originating ...
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0answers
58 views

Does light accelerate when it meets a surface? [duplicate]

Does light accelerate when it meets a surface like mirror, we know that light changes path when it meets a surface like mirror.If light changes path,even if travelling at c,this means light has ...
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1answer
217 views

is copper a non-magnetic?

I'm working on an optics project that I'm using Fresnel Equation for Intensity. but I've got a question, is copper a non-magnetic ? You know because in Fresnel Equation, for non-magnetic materials ...
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1answer
67 views

What's the difference between two types of diaphragms?

What's the principal difference between aperture iris diaphragm and field iris diaphragm?
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1answer
48 views

Does “converge” mean intersecting and producing image when we are taking about convex lenses?

After reading the chapter on convex lens, I saw several places where "converge" is used. In the very beginning of the chapter, my book says "converging lenses bring light together". So I thought ...
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1answer
888 views

What is the frequency of the color black?

Our eyes don't see light; they detect vibrations in the 400-800 THz range that we call color. Since our eyes can detect the color we call black, what is its frequency?
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3answers
227 views

What is the total internal reflection?

From what I read, it sounds like when a light ray passes from one medium to the other, if the critical angle is reached so that the refractive ray is at 90 degree with the normal, the light ray does ...
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5answers
1k views

Why does an image form at the intersection of light rays?

If image is simply what we see, then why, when light rays bend in the atmosphere, enabling us to see the sun, is there no intersection of rays? The concept is strange. I can not relate it to anything ...
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2answers
27 views

How are aberration levels measured?

I was reading reading the paper: Predicting subjective judgment of best focus with objective image quality metrics when I come across this statement: Through-focus visual acuity (VA) was ...
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0answers
144 views

When to use lateral magnification vs angular magnification?

What is the essential difference between lateral and angular magnification (like why do we need to use both and when do we use which)? Also, is there a relationship between the two magnifications?
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2answers
3k views

Why is the index of refraction different for different wavelengths? [duplicate]

The index of refraction can be written as $$n=\frac{\lambda_v}{\lambda_m}$$ where $\lambda_v$ is the wavelength in a vacuum and $\lambda_m$ is the wavelength in the medium. I’ve been told that since ...
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1answer
38 views

Recreating an image from a photometer or similar light-detecting device?

I'm thinking if it is possible to recreate an image from data from this kind of device. It is known analog signals theoretically have infinite resolution, but since we use them in discrete systems (...
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0answers
175 views

General proof of formulas of geometric optics?

In most lf textbooks formulas of geometric optics like lens maker formula and base formula for that are proven (or rather verified from my point of view) by taking specific case (ray diagram) and ...