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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What are the practical consequences of “approximate” quantum cloning with a stimulated emission cloning machine?

Say I build some stimulated emission-based cloning machine for photons (e.g. some active laser medium). Alternatively I could do cloning via interference, e.g. a linearly polarized photon could be ...
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19 views

Fraunhofer Diffraction using lenses

I've come across a question that I don't know how to tackle: An alternative way of observing Fraunhofer diffraction uses lenses to provide appropriate conditions. Sketch an optical configuration ...
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5answers
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+50

Why do nearsighted people see better with their glasses *rotated*?

If you are nearsighted (like me), you may have noticed that if you tilt your glasses, you can see distant objects more clear than with normally-positioned glasses. If you already see completely clear, ...
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11 views

Modern Optics (Fowles) Transmittance as a function of wavelength [on hold]

I need to get the coefficient of finesse to equal ((n^2-1)/(2n))^2 from 4R/(1-R)^2 knowing that the incident beam is normal so that R=((n-1)/(n+1))^2. If this isn't possible I'm not understanding the ...
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0answers
43 views

Why exactly are images formed by lenses/mirrors?

I just don't get the concept behind why a lens or a mirror forms a reproduction of the object at present. Is it to do with the object blocking parts of the light source? I just don't understand why an ...
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2answers
46 views

Optical absorption — what are the common ranges and mechanisms?

So let's say you do some reflection/transmission spectroscopy of a material. It's clear that it's absorbing in some range. What would be your first step in identifying the source of the absorption? ...
3
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1answer
54 views

Reconciling total internal reflection and the evanescent Wave

I understand that light is guided in a dielectric waveguide via total internal reflection. My question is regarding the origin of power contained in the evanescent field traveling along the direction ...
2
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3answers
56 views

Why can colors be mixed? [duplicate]

We can combine colored light, creating other colors, at least in terms of visual perception. But how it the result physically "a different color" - if it is at all? Or is all this not a physical ...
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1answer
37 views

Photovoltaic IV data

I am looking for any available measured solar-cell datasets (Voltage/Current) especially for organic photovoltaic cells for the testing of a software unfortunately I am unable to get the measured ...
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1answer
30 views

What is the effect of total internal reflection on polarized light [on hold]

Total Internal Reflection causes phase change of a light beam. I searched for effect on a polarized light beam by Total Internal Reflection but could not find much. I am assuming polarization does not ...
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0answers
6 views

Can a $TEM_{00}$ beam incident on a confocal cavity along its optical axis excite modes other than $TEM_{00}$ in the cavity?

Can a $TEM_{00}$ beam incident on a confocal cavity along its optical axis excite modes other than $TEM_{00}$ in the cavity? If not, is the FSR of the confocal cavity $\frac{c}{2L}$ in this case, ...
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2answers
900 views

Why doesn't my pinhole camera work?

We all know that light travels in straight a line, which can be proved by pinhole imaging as in the picture shown : But when I'm doing this little experiment with an apple, no matter how I change ...
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1answer
102 views

Semiclassical description of EM waves reflection from metallic surfaces

Imagine an EM wave impinging on a metal. Fresnel's formulas tell us that no wave can propagate through the metal, or that the transmitted field is an evascent wave with some penetration depth ...
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1answer
50 views

How car headlight works?

There are two headlight of car. One having a light bulb between two concave mirrors (one mirror behind and other infront of bulb), and the other type of light only have one concave mirror behind the ...
8
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1answer
1k views

Why do we see laser beams?

A laser produces a coherent beam of photons with particular $\mathbf{k}$ and $\mathbf{\omega}$. So, if there is no particular $\mathbf{k}_0$ directed toward our eyes, why do we see laser beams? I ...
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1answer
29 views

Imaginary number for extinction coefficient in complex refractive index

In complex refractive index on a material, $n=n'+ ik$, the imaginary part $k$ is physical meaning, as it shows absorption in the material but it is an imaginary. How we measure an imaginary values in ...
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2answers
76 views

Total internal reflection problem — could the textbook be wrong?

This regards the following problem: A ray of light is traveling in glass and strikes a glass/liquid interface. The angle of incidence is $58.0^\circ$ and the index of refraction of the glass is $n = ...
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2answers
215 views

Finding the illuminance from a triangular light source

Since most light sources in games are point-like, it's pretty difficult to approximate area light sources with point sources. As triangles are a universal form to represent 3D models (thus area light ...
5
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2answers
119 views

Is my simulation result for unpolarized light correct?

This is a follow-up of this question. After that, I picked up some knowledge of FDTD (an algorithm for solving Maxwell's equations) and simulated following scene: Pic 1 As the picture shows, a ...
3
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1answer
403 views

Fresnel Diffraction at a circular aperture

In Fresnel Diffraction at a circular aperture the central image according to 'Optics' by brij lal and subramanyam will be bright if odd number of full half-period zones can be ...
3
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2answers
108 views

Diffraction by a lens

The fraunhoffer treatment of circular apertures yields a diffraction pattern of circles, with the first minimum (dark ring) at an angular radius of $\theta$ where $\sin(\theta)=1.22\lambda/b$, where ...
11
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1answer
2k views

Why does paper become transparent when smeared with oil but not (so much) with water?

When I smear oil onto a scrap of paper and rub it in, the paper becomes quite transparent; but when I attempt the same with water it doesn't as much. Why?
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Resonance condition in confocal cavity

In a confocal cavity, a beam traverses the length of the resonator 4 times between two transmissions along the same ray. . For example, in the above figure, path difference between two beams that ...
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1answer
52 views

Negative radiation pressure from negative refractive index?

I see this claim being originally made by Vesselago (the discoverer of the principles of metamaterials) and indeed in contemporary papers. It means that such a metamaterial would be pulled towards its ...
2
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1answer
184 views

Apparent size of objects under 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 ...
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3answers
461 views

Lasing in a 2-Level system?

What exactly is the difference between 2-Level, 3-Level and 4-Level systems? Why can we not achieve stimulated emission in a two-level system using optical pumping?
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1answer
22 views

Practical hardware question regarding optical source for an array of fiber bragg gratings

I have a single 1 meter array of 5 fiber bragg gratings that has FC/APC connectors on both ends. I will be embedding the array in a material and want to be able to do a quick check that the array is ...
2
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1answer
21 views

Are Verdet Constants Temperature Dependent?

The Verdet constant of a magneto-optical material shows up in the calculation of the rotation of polarized light in a medium submerged in a magnetic field. The amount of rotation is given by $$ ...
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1answer
41 views

Is the plane wave model always valid in reflection and transmission?

my question is related to another one I asked, but I foolishly made that question about several things (experiment, computation, theory) at once so it was confused. I was talking to my boss about ...
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1answer
19 views

Why do the RGB gamut vertexes not intersect the edges of human vision on the CIExy plot?

As I understand, the CIExy graphic maps "greenness", or rather middle-wavelengthness, to the Y axis and "redness", or rather long-wavelengtsness, to the X axis. The trapping used to reduce the 3d ...
2
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1answer
24 views

Does ordinary refraction exert a couple on the refracting medium?

Refraction gives rise to a momentum change orthogonal to the propagation direction. This must result in an equal and opposite change to the medium at the boundary. Entry and exit cancel, and the ...
5
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1answer
106 views

The skin effect and the reflectivity of gold

I am simulating a waveguide in COMSOL, a FEM solver. My model looks like this (it is similar to a standard Quantum Cascade Laser geometry): Therefore there is a very thin (30nm) layer of gold ...
5
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1answer
148 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 ...
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33 views

Fraunhofer Diffraction [closed]

A 1-dimensional aperture is illuminated by a parallel beam of light of wavelength $\lambda$ and the diffraction pattern is viewed on a distance screen. Show that the amplitude of the diffraction ...
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4answers
67 views

What's the difference between Raman scattering and second harmonic generation in crystal?

As far as I know, the Raman scattering is from the stokes and anti-stokes scattering that the laser light interact with molecular vibrations. So we know that ""laser light interact with molecular ...
5
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1answer
60 views

What is fidelity in experimental QM?

I often comer across the term high fidelity in QM papers. Does fidelity imply ratio of entangled photons / total photons? Is there some other metric to measure how good the source is?
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29 views

Difference between the increase in optical path due to refraction and that due to reflection

If we place two glass plates of refractive index n and each having thickness t,on the way of a light ray the increase in optical path becomes (S2P-S1P)=2(n-1)t due to refraction through them,and the ...
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0answers
28 views

Optical brightener in plastics? [closed]

Is there any way to add some type of 'optical brightener' to a PC+ABS molded part? I'm looking for something that will not affect the color / gloss. Ideally it will be a material that can be added ...
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0answers
40 views

Geometrical optics assumes light as particles?

I've been studying optics for a while and the first thing I learned was geometrical optics where we think of light as rays and use Fermat's Principle of least time to guess the path light follows. On ...
5
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2answers
138 views

Why must an integrating sphere be a sphere?

Why must an integrating sphere be a sphere? Why can't it be an integrating cube? What is the difference? Could I use a cube to measure total illuminance like an integrating sphere does?
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2answers
66 views

Locations of destructive interference for two spherical waves

I have looked at this, but it did not help with locations. Really this just comes down to mathematical manipulation, which for some reason I fail to see. Here is my paraphrased setup: Consider two ...
4
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2answers
75 views

Wave or particle in the end

In Young's double slit experiment I put a convex lens after double slit and direct interference pattern on to a fibre. Then I expose the other end of fibre to a screen. What will I observe - the ...
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1answer
57 views

What is the near point for the eye

So I am a teaching assistant for an introductory physics class. One of the problems on this weeks workshops is: Where is the near point (far point) of an eye for which a contact lens with power of ...
2
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2answers
60 views

How fast is wave propagation in interference?

When someone performs Young's Double Slit experiment, the person sees an interference pattern on the screen. What is the time taken to for the pattern to appear on the screen? Is it distance between ...
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0answers
39 views

Alternate young double slit experiment

What will happen in young's double slit experiment, when instead of screen I put a black screen with a hole and a second screen behind the black one. Will it still form interference pattern albeit a ...
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1answer
121 views

Doubt in question related to optics---magnification?

Ok here is the question given in my text-book Find the distance of the object from a concave mirror of focal length 10 cm so that image size is 4 times the size of the object. The solution in my ...
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1answer
141 views

Myopia / Hypermetropia eye glasses inverting image on retina

As far as I'm aware, the eye acts like a pinhole camera in that it inverts the image on the rentina. This makes sense as the rays converge and form a focal point that is upside down. Myopia ...
5
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1answer
68 views

Is it possible to see light intensity fluctuate?

Solutions to Maxwell's equations shows that the $\vec{E}$ and $\vec{H}$ component are of the same phase, which means they go to maximum and zero together, therefore the intensity of the ...
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1answer
34 views

Mean free path of a photon in a fiber

Is there a way to calculate, or a reference table I can to look up which provides the average distance a photon travels before it encounters an electron and is absorbed or re-emitted in a fiber optics ...
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1answer
46 views

Holographic Image

In a holography set-up, as shown in the figure below, Illumination beam and reference beam both are in phase. The interference pattern generated at the detector contains the whole information about ...