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 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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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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36 views

Optical signals and the electromagnetic spectrum [on hold]

Are Optical signals are not considered part of the E-M spectrum? Or are they?
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42 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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75 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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37 views

Determining focal length and positions of principal planes [on hold]

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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29 views

Showing the relationship between focal ratio and brightness [on hold]

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
16 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
23 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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18 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
38 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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46 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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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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20 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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3answers
145 views
+50

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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125 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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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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36 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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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
34 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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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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45 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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15 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
58 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
49 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
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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 ...
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2answers
56 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
28 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 ...
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46 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
42 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 ...
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22 views

What are the figures of merit/ performance measurements I can use for deconvolution?

I'm currently performing deconvolution on a bunch of 2D slices of fluorescent beads using MATLAB. Now I want to measure the performance of different deconvolution methods on the filtering of the ...
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0answers
20 views

How to spread out a beam from a moving head [closed]

I have a couple of small moving heads available here I'm using them for the band to focus on particular musicians sometimes and I would like to be able to make the beam angle wider. Sometimes I have ...
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2answers
34 views

Why does resolution decrease due to out of focus blur?

Reading the Wikipedia article on Brightfield Microscopy and I notice the point: 'Low apparent optical resolution due to the blur of out of focus material.' in the Limitations section. I ...
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1answer
21 views

Total number of primary maxima in diffraction grating

I am trying to determine the total number of primary maxima that can be observed when light of wavelength 500 nm is incident normally on a diffraction grating, with the third-order maximum of the ...
3
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1answer
60 views

Why is there “ringing” at the violet end of a rainbow but not the red end?

I've recently noticed that if you look closely at the violet end of a rainbow, you can see a sort of "ringing" effect where there are alternating bands of color and lack of color. You can apparently ...
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10 views

Does the distance away from a plane mirror affect the Image seen by the eye? [duplicate]

Does the distance away from a plane mirror affect the Image seen by the eye? According to my textbook, it doesn't. However in real life, I see less of myself as I get closer to a mirror.
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Position in reciprocal lattice (for Triangular real lattice) to find photonic gapmap

To find Gap-Map, using FDTD, for square lattice of dielectric coulumns in air, I choose the 'X' position in reciprocal lattice, while varying the radius of the rods. The result is good. But while ...
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2answers
50 views

Can focused light be treated as a point source?

Imagine there is a uniform, collimated beam coming from a distant light source. This beam passes through a lens and is focused to a point at the focal length. Can this "point" be treated as a point ...
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2answers
203 views

Why is diamond transparent while graphite is not?

Diamond and graphite are both made of the same atom, carbon. Diamond has a tetrahedron structure while graphite has a flat hexagonal structure. Why is diamond transparent while graphite is not (at ...
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34 views

Derivation of the formula related to number of images?

I have read in my book that if two mirrors are inclined at an angle $\theta$, if 360/$\theta$ is even , the number of images is given by (360/$\theta$) -1 What is the derivation of this formula? I ...
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1answer
35 views

Why does the 4f lenses configuration decrease aberration? [closed]

In many publications/lectures it is said that the 4f lenses configuration is the preferred configuration for imaging. My question is why does this configuration in an imaging actually minimizes the ...
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2answers
61 views

Can light be rotated using lenses or prisms?

I was wondering if it was possible, by using only lenses, mirrors, or prisms, to rotate a ray of light coming from a certain direction. For example, if I have two lasers beams side by side, is it ...
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2answers
49 views

What happens to scattered light when intensity of light increases?

Does increasing the intensity of the incident light increase the proportion of the light that is scattered?
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25 views

Terminology - optical (visual) properties of a structure

I am trying to understand few terminological problems that I encounter. Without knowing keywords it is hard to perform search for literature or publications in the area. The area relates to the ...
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1answer
29 views

Why does this illumination pattern of an LED light going through a small pinhole not emulate the point spread function?

I have an optical setup where a component LED passes through a 50 um pinhole, and creates an illumination pattern on an image sensor approximately 5 cm away that looks like the following: Now, I'm ...
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1answer
45 views

Is it possible to get a lasing from every luminescent media?

Let's assume that there is a cavity with a couple of mirrors and gain media between which possesses luminescence under some external excitation/pumping. Let the absolute quantum yield of the gain ...
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1answer
70 views

What happens to photons, electrons, etc [duplicate]

What happens to photons when they hit our eye? where do they end up? if they generate heat, why our eye don't get overheated? Similarly what happens to electrons when the light hits certain metals, ...