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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How to understand “the speed of propagation of the condition of constant phase”?

I still can't understand that the phase can be a constant until now. If the phase is constant, from the $$y(x,t) = a \times \sin(phase)$$ the shape of wave will be a line parallel to x-axis.But I ...
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69 views

Difference between single mode and multi mode optical fibres?

What is the difference between single mode and multi mode optical fibres? First off, I guess that by modes we mean the spatial modes of the electric (or magnetic?) field right? Now: what makes a ...
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33 views

Electric Field and Magnetic field of Guassian beam [closed]

The center of the gaussian beam in glass has a beam power of 1 mW and a beam radius of 20 μm (micro meter). The wavelength of the light $\lambda_0$ is 1550 nm. How can I find the electric field E ...
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64 views

Fate of light ray

This question has been on my mind since I first learned optics. Where will the light ray go? First, I thought of it taking a U turn. But, I don't think that will happen. Now I have studied a bit ...
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91 views

Polarization effects of second-harmonic generation (SHG)

In one of my labs, we were using an Nd:YAG at 1064 nm and we put it through a KTP nonlinear crystal to perform SHG. We noticed that before the crystal, the 1064 light was unpolarized, but the 532 ...
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388 views

What are the 'oscillators' in the Drude Lorentz model?

Jackson's Electrodynamics defines the Drude-Lorentz model as a set of harmonic oscillators (running over indices $j$ below), which, if you write out the equations of motion and rearrange a little, ...
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530 views

Photoelectric effect: current vs wavelength

In an experiment where the type of metal,intensity of light and potential difference across a battery is kept constant at 2V the results show that an increase in wavelength, obviously in turn ...
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271 views

Cylindrical Fresnel Lens Focus Problem

How to focus beam from the fresnel lens on a flat surface. In my case, instead of producing the light beam, I am receiving the light beam. So, the beam comes from the right and then focuses at a ...
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36 views

Query regarding interference

In Young's Double Slit experiment, why is it that two waves vibrating perpendicular to each other doesn't show interference? I know that for interference to happen, the waves must be coherent ( i.e., ...
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28 views

Microscopic origin of optical transmission

When light interacts with matter, it is abosrbed, reflected and transmitted. With repect to the UV-Vis range, electronic abosrptions occur, where if the incident photon mode matches the energy ...
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429 views

Is it possible to project an image onto water? [closed]

Is there a way to create an image/projection in the water? Or form the water to project an image, little dot/pixel? Use some type of frequency to modulate the little dot in the fluid?
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Refraction through prism

We know that the light gets refracted when it enter a medium low/high refractive index. But why light is not refracted when it comes out from the vertex of a prism.
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138 views

Beam focused through lens at an angle

Under normal lens operation, a beam is sent through the centre of the lens along the optical axis (ie perpendicular to the lens's plane). What happens when a beam is sent through a lens at an angle to ...
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291 views

Diffraction/Bragg's law : how does $2\theta$ come about?

I'm trying to get my head around a problem (I should have checked whether I had the answer in class, the exams are coming up now and I don't know if I'll get a lecturer response over the holidays) I ...
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41 views

Relativistic aberration - half-sky radius

With relativistic aberration, a sky full of stars gets concentrated in the direction of motion. As a rough measure of the degree of concentration, one could use the radius of a small circle, centered ...
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226 views

Infinite Mirror Face to Face With Infinite Two Way Mirror

If you are in deep space, and there is an infinite plane mirror, and in front of it there is another infinite mirror that is two way, with the see through side towards you, what do you see? Is it the ...
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108 views

counting refractive index of a plano convex lens [closed]

suppose that, there is a plano convex lens and its thickness is 5.00cm. If you watch it straight from the convex side, it seems that its of 4.4 cm. What is the refractive index of this lens?
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593 views

How do 3D glasses work?

I am really curious as how do 3D glasses work. I know that they uses some kind of circular polarizers but how does this actually make the screen jump right out at you?
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258 views

question about the focul length and the position of a convex lens [closed]

How can I determine the focal length and position of a lens mounted in an inaccessible position inside a tube by a laboratory experiment? Please help.
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103 views

Time duration for pulse of single electron viewed as a wave

Electron as an example has a de Broglie wavelength and could diffract. If it has a single wavelength the time extent of the particle's pulse duration would be infinite .. If it carries a broadband ...
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What is optical confinement?

What is optical confinement? What is it intuitively? How does this 'optical confinement' affect the performance of a laser?
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97 views

What is the optical illusion called where our sun seems to disappear from view and then rise on the third day? And where can it be viewed from?

What is the optical illusion called where our sun seems to disappear for 3 days and then rise again into view on the third day? And where can it be viewed from?
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408 views

Why cellphone cameras don't have optical zoom

I have just basic understanding of Physics from elementary school. But I still wonder, why after 10 years of cameras in cellphones, there is no "small-pack" optical zoom. I think there should be no ...
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158 views

Seeing the image as explained by Geometrical optics?

I was thinking about how the human visual system perceives the position of an object. I assume it essentially does this by focussing the incoming rays onto the retina and then judging from the power ...
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475 views

Confusing mirror problem

A piece of thin spherical shell that has a radius of curvature of 106 cm is silvered on both sides. The concave side of the piece forms a real image 79.5 cm from the mirror. The piece is then turned ...
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43 views

Can the choice of reflection angle for light can be derived from a minimality condition?

When the light hits on a surface, it reflects with the "same" angle as the one that hits the surface. I was wondering if this choice of angle can be explained by a minimality condition?
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255 views

Which fraction of light is refracted from a source of light under a lake?

I was trying to solve this problem: "A punctiform source of light is standing inside a lake, at a height h of the surface. f is the fraction of the total of energy emitted that escapes directly from ...
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192 views

Seeing a mirage through mirror?

Okay, I am not really good in physics (rather terrible), but nonetheless. So, I was just wondering if you can see a mirage, is there something special in our eyes that we can see it or what? I mean, ...
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378 views

Wavelength comparison of two waves

Is there any non-digital (naturally existing) mechanism to compare two or more waves in such a way: ...
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1k views

Are holograms like in this video possible? [duplicate]

http://www.youtube.com/watch?feature=player_detailpage&v=jfySIeS1XZE#t=118s If so, how are they created (roughly speaking). Earlier in the video he says that a laser scanned the surface of the ...
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194 views

Maximum resolution per lens size

This question is more practical than theoretical, but I am interested in the theoretical considerations as well. My wife just bought a Samsung S3 phone with a 8 MP image sensor hiding behind a tiny ...
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127 views

What is primary reason for a matter to be transparent as Cornea is?

Is it because its internal structure is Crystalline? I mean by transparency following.
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359 views

Width of Gaussian Beam and Refractive Index

I know that in free space, the width of a Gaussian beam can be written as $W=W_0\sqrt{1+(\frac{z}{z_0})^{2}}$. However, I was wondering if it was possible to express this width as a function of ...
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75 views

How to determine the angle a camera has to be at to image a desired scene, given the camera parameters?

Reviewing old material I learned years ago, having a hard time rewrapping my head around the relationships in capturing images from a camera. Imagine a scenario with the camera placed on the ground ...
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169 views

Merge different wavelength rays

Let's say an array of rays of light is given. Each ray has a specific wavelength (in the range of visible light). Example: ...
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50 views

Do parallel rays reflecting at a mirror not intersect at one point? [closed]

Let's take a concave mirror with $CP$ as its principal axis. Let's assume that a parallel ray $p$ to $CP$ reflects at $A$ to pass through the focal point $F$. Then, $\angle CAF=\angle ACF$, which ...
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25 views

Optics Spatial Resolution

what does it mean to have a micrometer spatial resolution. Does it mean the resolution is 1 micrometer or can be 2,3,4,.... etc.? I do not understand it. Is there anybody?
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52 views

Why isn't this calculation of the energy of a light wave correct? [closed]

I'm trying to calculate the energy $J(T)$ that monochromatic light wave with electric field strength $E(T)$ supplies to unit electric charge over period of time $T$: $J(T)=\int\limits ...
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81 views

Why do sea waves seem to be standing still when you look from the window of an airplane?

Looking from the window of a passenger plane even at moderate altitude such that one can still recognize individual waves and even something like white foam, and small boats close to the cost line, it ...
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58 views

images of objects at infinity

Is the focal point of our eye lens is on the retina? if it is so why dont we see point image of infinite object because light rays coming from them are parallel to each other and converges at focal ...
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Use two polarizing filter without liquid crystal between them to render static image

I'm going to demonstrate the work of polarizing filter. I have a tablet for this purpose with disassembled LCD panel which is fine but it is bulky and overkill. Is there any other material that may ...
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46 views

Michelson-Morley experiment

I have to do an experiment about light. I preferred to measure the speed of light by the experiment of Michelson and Morley. When you do the experiment, it will result in an interference pattern by ...
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hexagonal patterns when we look at bright light or sun

when we look at bright light or sun, we many a times hexagonal patterns are observed. these are easily observed when we click their images. why all this happens? is all this is just a lens flare or is ...
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45 views

How is angle measured by telescope in spectrometer is twice the prism angle [closed]

While measuring the angle of the prism with the help of telescope in a spectrometer (see figure below), the observed angle is twice the angle of the prism. Can someone prove it geometrically? Edit : ...
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61 views

Optical system for cloning an image of a light source?

I need to create an optical system for cloning an image of a light source to human eyes. Is there a correct solution(design) for this problem. Reflectivity of the mirrors must be equal. Because ...
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40 views

What is the maximum of information in a beam of light?

If I look at the space I can see the Andromeda Galaxy as a small dot in the sky. If I look through a telescope, I can see the spiral shape. If the saw right through a huge telescope, I could see a ...
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32 views

Path length requirement for diffraction problem [closed]

The following question has been asked in a problem sheet I have been asked to answer: "The above diagram relates to the path lengths of radiation, with an angle of incidence, θ, reflecting off ...
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50 views

Metal Refractive index

I'm working on Fresnel equation for calculation of reflection of a light (532 nm) on Iron. I've got a question: Is metals refractive index always a real number or it can be a complex number?
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59 views

Light absorption according to “Beer-Lambert” law [closed]

Beer-Lambert equation tells us the measure of absorption of light when it enters to a liquid and comes out from the other side. But I have a question there: Suppose a glass that filled with water. ...
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Light absorption for different liquid

when I was working on a cylindrical glassy bottle that filled with water, I found that the initial light intensity is less than the final light intensity. (It's clear but I experiment this) This is ...