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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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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23 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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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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894 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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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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43 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 ...
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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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28 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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75 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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+50

Why 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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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 ...
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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 ...
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399 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 ...
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104 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 ...
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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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50 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 ...
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174 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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456 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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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 ...
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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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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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18 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 ...
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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 ...
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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 ...
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147 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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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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43 views

Snell's law in MATLAB [closed]

writing homework, I ran into a problem. One year ago we had to create something like a model of Snell's law. In the first picture there should be a ray that is reflected at the interface of two media. ...
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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 ...
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1answer
59 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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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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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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39 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 ...
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134 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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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 ...
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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
54 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 ...
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2answers
59 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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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 ...
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67 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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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 ...
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1answer
221 views

Fraunhofer diffraction simulation for a hexagonal aperture, what are the typical units?

Kostya answered a question that was asking what the diffraction pattern looks like for a hexagonal aperture in front of a lens. He lists an equation which was derived using a Heaviside function to ...
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103 views

Question about the wave nature of light

I quote from my textbook, " Consider two vertical slits S1 and S2 placed parallel to each other, and a string is passed through them. The end B is fixed and A is given jerks perpendicular to its ...
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55 views

How to calculate loss due to Gaussian beam divergence of a laser going through multiple lenses?

To better explain my question, I will need to give a brief description of the configuration used in 2D MEMS switches. So, the next figure shows a configuration of a 2D MEMS switch, a light beam ...
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2answers
35 views

Why a minus in the equation of a paraxial plane wave?

paraxial plane wave = $\exp{(-jkz)}$ for waves propagating to the right I can't figure out why it's not $\exp{(+jkz)}$. Any help would be greatly appreciated, thank you.
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When polarized light hits a polarizer, what happens to the polarization which is not transmitted?

It is typically said that in polarization of light only those waves can pass through a polaroid which has a plane of vibration parallel to the axis of polaroid. My question is: what happens to the ...
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Will overlapping two different beams of coherent light cause interference?

I have two laser beams with same polarization running parallel to each other. Will they interfere? If yes, then what are the conditions (perpendicular distance etc) and how can I observe the ...