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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Diffraction pattern in the image plane?

Consider the setup below: In all cases the relationship between $u_o(x_o)$ and $u_f(x_f)$ is given by a Fourier transform. My question is, when is the same true for the relationship between ...
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9 views

Collimation and the inverse square law

This is my understanding of how the inverse square law applies to collimated light, and specifically laser light, since AFAIK it's the only light that can be collimated with any accuracy thanks to ...
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2answers
25 views

The image of a wall clock is to be obtained on the opposite wall 2m away by the means of a convex lens. What is the minimum focal length required? [on hold]

I'm in 10th grade and this question came in my physics test. Nobody was able to answer this question correctly except my physics teacher who says that the answer is 2m. My answer is that there should ...
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1answer
29 views

Phase differences due to reflection etc [on hold]

http://www.physicsgalaxy.com/lectures/1/30/1749/Solved-Example-15#42 see this link(only question) and see 1:21. Phase difference is given as $2\mu t$ but shouldn't it be $2\mu ...
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1answer
28 views

Plane waves intensity

Our professor said that a plane wave has the same intensity in the plane perpendicular to it's propagation. I can't really make sense of how that is possible. I mean, shouldn't the intensity decrease ...
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1answer
26 views

Calculate the laser heating on a crystal

Let's say I'm doing an optical experiment. I focus a laser on a crystal with a certain amount of power. The crystal's temperature is regulated to a certain temperature but it is localy heated by the ...
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1answer
20 views

Why does narrower slit give a wider diffraction pattern in single slit diffraction?

I was reading on this website and it said that one of the characteristic of single slit is narrower slit give a wider diffraction pattern but why? ...
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1answer
25 views

Polka dot beamsplitter. Is it good for gaussian beams

I am doing pump probe and I am looking for beam-splitter which will not affect beam polarization too much, as I intend to measure polarization dependencies. I have heard of polka-dot beam-splitters ...
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1answer
24 views

Wave optics physics

When does monochromatic beam of light incident on a reflective surface get completely transmitted.according to the question what exactly the word transmitted means? I'm little bit confused .could you ...
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Why does conservation of étendue matter when showing one cannot focus light to arbitrary temperatures?

The latest XKCD What-If post discusses how one cannot start a fire by focusing the light from the moon. The answer is no, for well-established reasons, but the explanation isn't watertight. Maybe ...
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20 views

Are the Rayleigh criterion and the Point Spread Function related to each other?

Reading this paper as of now, and at the very end of the appendices, it mentions that: However, assuming a highquality preparation, the limit of resolution for any application is always ...
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2answers
39 views

Seeing red color against violet

If you put a red dot and violet dot on a wall and move far away from them, after certain period/distance you will only be able to see the red light, then my teacher explained why/how this happens , ...
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Can a biconcave thick lens ever have a positive focus? I.e. if both sides have radius of curvature -/+R?

Since a thin biconcave lens has a negative focus, can a thick biconcave lens with a certain thickness have a positive focus if both sides have the same (magnitude) radius of curvature?
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2answers
45 views

Why don't eye lenses alter depth perception?

What it is going to do is bend the rays so that light from infinity "appears" as though it is coinciding with a person's far point. In doing so, it allows the person to see a clear image, without ...
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1answer
35 views

Single slit diffraction - choosing a wavelength?

For the classic experiment of determining the slit width of a single slit. If we assume the rough order of magnitude of the width is known. What factors determine the choice of wavelength? (Clearly ...
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1answer
41 views

What is the math behind the smartphone fish eye lenses

I found out information that these add-on fish eye lenses for smartphones have a focal length of about 2mm. I bought a lens and tried it with several different phones and it worked. I found out that ...
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1answer
22 views

How can I change the divergence angle of a single mode fiber

For my project I use the end of a single mode fiber as a "transmitter". I need to set the divergence to 20 micro radians. Is there an equation how to calculate the divergence and the necessary optics ...
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1answer
41 views

why do light bulbs explode when in contact with water?

Is it true that when water pours on a light bulb it will explode? If so does this apply to all light bulbs and how does that happen.
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2answers
82 views

How is refractive index related to the density of a medium (for example, air)?

I have a question regarding refractive index dependency on the density of a dielectric, specifically air. Background Let us start from Newton's second law form of driven harmonic oscillators ...
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0answers
40 views

Optical signals and the electromagnetic spectrum [closed]

Are Optical signals are not considered part of the E-M spectrum? Or are they?
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1answer
45 views

Why does magnetic field and not electric field invert in a reflection? (related to another question)

When you are talking about an elctromagnetic wave that reflects on a surface (for example here), why do you say that the reflected magnetic field inverts and not the electric field? \begin{align} E_+ ...
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2answers
79 views

How far do we need to be removed from the earth to show the curvature with a viewing angle between 42 and 48 degrees? [duplicate]

I have seen already a couple of answers but none of them give an exact number of what should be the minimum height where we would be able to record the curvature of the earth All I could find is ...
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0answers
41 views

Determining focal length and positions of principal planes [closed]

I have been stuck on this problem for a few days now, and I am still not confident which approach to take with this question. I am consider using the Gullstrand Equation, but I hear some of my ...
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0answers
33 views

Showing the relationship between focal ratio and brightness [closed]

I have an optics question that I have been stuck on for a few days now and I really need some guidance. Any help is appreciated! Question: The f-number (focal ratio) of a lens is the ratio of a focal ...
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1answer
18 views

Signal loss in non-reflected light through a tube proportional to square of the length?

Reading a patent I came across the claim: "...a portion of light intersecting the inner metal surface is not reflected, resulting in a loss in signal intensity... the signal loss is proportional to ...
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1answer
26 views

Why eyepiece does not resolve image formed by objective lens further?

In my book it is written that "The angular resolution of the telescope is determined by the objective of the telescope. The stars which are not resolved in the image produced by the objective cannot ...
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0answers
19 views

DIY optical band pass filter or another alternative

I need to detect laser using a solar cell which would need me to either detect the laser wavelength or use pulse modulation and detect the frequency so I'm kinda here to ask if it's possible to simply ...
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1answer
40 views

Will smoke affect young's double slit experiment

If smoke is present in between the screen and slit in Young's double slit experiment using laser, will there be any change in the interference pattern? Will the fringes be obtained on the screen? ...
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1answer
29 views

Why rainbows form around flashes?

I read that to see a rainbow, your back must be towards the sun, and you have to look at roughly 42 Degrees from the imaginary line to spot the red band. But many times, me and many of my friends see ...
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2answers
50 views

Why do you need at least two rays to form an image?

Why isn't enough one light beam to form an image in your retina for example?
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0answers
31 views

Sign convention in geometrical optics

This is slight misconception that has bugged me. While deriving the mirror formula: $$\frac{1}{u}+\frac{1}{v}=\frac{1}{f},$$ people (as per my reference book) tend to apply the sign convention to ...
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2answers
23 views

Holography with object and reference waves with a slightly different wavelength

Recently I've been looking into holography, where one interferes the object wave with a reference wave and encodes their combined intensity on a transparency, so that if one then re illuminates the ...
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5answers
224 views

Blue light filtering

Prologue: my knowledge in these topics is fairly limited, so please feel free to point out the mistakes or the not-so-clear points, and bear with me for the oversimplicity of the language used. I was ...
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2answers
136 views

Why does a laser beam stay collimated?

I am looking for a simple way of explaining the collimation of a laser beam. The typical discussion of the two slit experiment of quantum theory relies heavily on the Huygens principle. Its ...
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14 views

Best books on wave optics for undergraduates [duplicate]

i want to know about the books that i can use for the study of wave optics
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1answer
45 views

Wave vector relation in nonlinear material

A light wave ($k_1,\omega_1$) travels in a medium of refractive index $n_1$ and then encounters a nonlinear medium ($n_2$) under the angle $\theta_1$. Snell's law tells us the wave's direction in the ...
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0answers
19 views

Temperature influence in Optical Quantum Computing

I've recently been looking into the (perhaps a bit outdated but still very interesting) field of linear optical quantum computing. Using photons as information carriers, and using objects like ...
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1answer
35 views

In Young's double slit experiment the fringes are non-localised. Why? [closed]

What is meaning of non localiesd fringe ?Why they are non localised ?
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0answers
48 views

What is the reason behind total internal reflection?

I know that when we increase i , r increases unevenly, i.e i increases a little but r increases with a greater amount. At some time, when i reaches the critical angle, r becomes 90 and if we further ...
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0answers
47 views

Why must this boundary condition be met? (Electromagnetic wave at interface between two mediums)

My textbook says that The laws of Electromagnetic Theory (Section 3.1) lead to certain requirements that must be met by the fields, and they are referred to as the boundary conditions. ...
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0answers
16 views

Phantom blue lights under white LED headlights?

Why do I see phantom blue lights just under (and a little to the left) of white LED headlights? They appear over where the fender is, so just a few inches below the actual lights. As the vehicle ...
3
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1answer
59 views

The many faces of electromagnetic waves

In my waves and optics class, we have learned several ways to treat electromagnetic waves: light rays (geometric optics), electromagnetic plane waves, spherical waves, cylindrical waves (2D). One ...
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1answer
52 views

Is Huygens's Wave Theory still correct?

We have to study on details about Huygens's Wave Theory though we have Electromagnetic theory, quantum theory today. Is it still correct or not?
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1answer
44 views

How we are able to see red and green colored objects simultaneously if combination of red and green produces yellow?

If red and green cones in our eyes are tiggered simultaneously then our brain makes us see yellow color. But if two objects which have red and green colors respectively are placed infront of us then ...
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1answer
21 views

Why does Diffracted Light cone diameter change in relation to angle of light beam?

I have a question about light diffraction. Take a look at these images of the Pantheon oculus. Now what I don't understand, in the first picture, the light is coming in from overhead and forms a ...
2
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2answers
59 views

Medium with refractive index less than unity?

What I really can't understand,What are the properties of a medium with refractive index less than unity?how does it effect light rays which fall on them?
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2answers
29 views

Total internal reflection in a simple pane of glass - why can we see through?

Consider looking through a glass window pane at high angles of incidence. At the front face of the pane, there is no total internal reflection since the light is traversing an air to glass interface. ...
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1answer
29 views

How do we call in English scientific terms the Fermat's principle about back and forth light traversal?

We know that the path followed by the light from point A to point B is independent of the direction of propagation of light. This is what is called in French "le principe de retour inverse de la ...
2
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0answers
57 views

Why should angle of incidence be equal to angle of emergence for minimum deviation in a triangular prism?

When I was solving questions on Ray optics I encountered a question wherein I had to prove that when a ray of light undergoes minimum deviation through a triangular prism then both the angles of ...
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1answer
43 views

When is a negative focal length used in optics?

I'm getting confused with conventions. I was wondering if this logic is correct: If an image appears on the same side of an object, then we use a negative focal length for determining information ...