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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is it possible to extract spectrum (color in general) from an animal [on hold]

if i may ask....can this be ASAP? :3 my problem: okay this is going to sound lame, but i was wondering if it is possible to extract color (specifically spectrum) from an animal. this question ...
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0answers
13 views

How does a polarizing beam splitter work? [on hold]

How does a polarizing beam splitter work for a S-polarized or P-polarized beam?
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1answer
23 views

Shack-Hartmann wavefront sensor concepts, pupil conjugate planes?

I am just starting to looking at the application of wavefront abberommtery to measure abberations in the human eye. I am confused over the pupil conjugate planes, do you use relay lenses to image the ...
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2answers
52 views

Safety glasses for a CO₂ laser

I am working on a CO$_2$ laser project and I know glass blocks the wavelength of the laser, 10,600 nm, well. So, should normal glasses work good as safety glasses or do I need to buy a specific one? ...
2
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2answers
66 views

Why can't we reach the ends of rainbow?

Rainbows are spectacular things. But I imagine why we can't reach to the ends of rainbows. Do rainbows have no ends ? If so, why can't we reach at them? If you go closer,they will go further. Why?
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1answer
48 views

Diffraction to be explained without Huygens principle

Can we explain diffraction without using Huygens principle?
2
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1answer
60 views

Why do propellers look like they are moving really slow when they are moving really fast?

I was just looking at an airplane video and was wondering why it looks like the propellers are moving relatively slowly when they infact have a RPM in the thousands probably.
3
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2answers
65 views

Spherical mirror ray diagram question

why does a ray, parallel to the principle axis, intersect the principal axis at half the radius of curvature, i.e. focus? EDIT I was taught that in a spherical concave mirror, the rays parallel to ...
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20 views

Difference b/w angular width and linear width of fringe

In double slit experiment and single slit experiment what is the difference between angular width of fringe and linear width of fringe?
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1answer
29 views

Does Bragg's law take into account atom size? (And should it?)

Bragg's law explains wave diffraction and interaction when electromagnetic waves hit a lattice structure: $$n \lambda = 2 d \sin \theta$$ See picture and details on Wikipedia. I am wondering if ...
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1answer
20 views

How can you determine the direction of the polarizing axis of a single polarizer?

How can you determine the direction of the polarizing axis of a single polarizer?
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0answers
13 views

Proof of the Burns-Schlueter Theorem

In a multiple lens system, when the image of the first lens lies behind the second lens, you treat the second lens as a lens of its negative focal length. That is, a converging lens becomes a ...
0
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0answers
30 views

Upside down images on the surface of the water [closed]

If you look up from underneath toward the surface of the water in your aquarium, you may see an upside-down reflection of your pet fish in the surface of the water. Explain how this can happen.
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1answer
26 views

Difference between sound wave and lightwave scattering [closed]

What are the main differences between sound and light scattering starting with the Helmholtz equation? (Preferably by circular cylinder)
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1answer
27 views

Ideas for improvised UV filter

I am doing a project where I would like to do some UV exposure to some concrete and stone samples. Therefore I have bought a couple of 400 watt UV bulbs, the product specification says it has an ...
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1answer
104 views

Intuitive explanation of Huygens construction?

I am having problems thinking about Huygens construction when a wave front hits a surface and am looking for an intuitive / easy to understand answers of the following points consider the diagram ...
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1answer
33 views

Why does an external laser drive only couples certain levels?

I was always wondering how is it that all the quantum optics levels schemes are depicted as if the laser couples only two certain levels with some frequency. For exmaple the standard lambda system ...
2
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1answer
82 views

Is the Wikipedia article on the Kramers-Kronig relations correct?

Reading the "Physical interpretation and alternate form" section of the Wikipedia article on the Kramers-Kronig relations, it says: The imaginary part of a response function describes how a system ...
4
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2answers
163 views

Is manufacturing roughness really the only reason we don't see optical interference in thick dielectrics like windows?

I had always kind of wondered why we didn't see interference in things like windows -- we were taught that the condition is that the thickness of the film/slab/medium just has to be an integral number ...
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0answers
34 views

Caustic airy equation and divergent series [closed]

How is the behaviour or creation or mathematical explanation of a caustic related to the divergent power asymptotic series in the limit $ x \to \infty $?
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1answer
29 views

Can circularly polarized light be transmitted through a fiber

Can circularly polarized light be transmitted through a fiber without loss of this polarization or will it just end up as linearly polarized light on the other side? Does polarization-maintaining ...
1
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2answers
42 views

How to make a rotating linearly polarized (not circular polarization) beam from a single beam?

One way to make a linearly polarized beam rotating at frequency $\Delta f\approx10\mbox{MHz}$ is by combining two circularly polarized beams, one left-handed and one right-handed, and where one beam ...
2
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0answers
53 views

Can time pass for a photon if it's moving in a medium? [duplicate]

If time does not pass for a photon traveling at the speed of light, which can only occur when traveling in a vacuum, what happens when it is slowed down by traveling through non vacuum space like ...
2
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2answers
114 views

Are there any ways to alter frequency of wave?

I want to know how can we change frequency of wave, both sound and light, and what is the nature of "changing frequency" Such as, any material could absorb and re-emit wave in another wavelength. Or ...
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0answers
30 views

Off-Axis Parabolic Mirror Elliptical Collimated Beam Shape

When you collimate a point source using an off-axis parabolic mirror (OAP) with a circular shape, the beam area of the collimated light becomes more and more elliptical (x-dir. is smaller than y-dir.) ...
6
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2answers
58 views

Collinearity of two infrared (10.6um) beams

I'm interested in aligning two infrared (10.6um) beams so that they are as collinear as possible. What is the best way to do this while maintaining the polarization of the two beams? Is there a ...
0
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1answer
35 views

Why we take two focuses in concave and convex lenses before the lens and behind the lens [closed]

we take f(one) and 2f(one) before the lens and f(two) and 2f(two) behind the lens.
2
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0answers
31 views

Why the Caustic of a circle is the most bright curve in the circle?

Caustic of a cirle is the envelope of light rays reflected by a circle, which is the most bright curve in the circle. But why? Here is the picture shows the Caustic of a circle.
3
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3answers
101 views

Visible light and colors

I recently read an article about quantum chromodynamics which suggested that quarks do not have actually colors because their dimensions are smaller than the wave length of visible light. My question ...
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1answer
24 views

Optical Activity

I was wondering, does the optical activity of a material change under a magnetic field? Assuming it did, how would one analyze this phenomenon in the eyes of classical electrodynamics or classical ...
57
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5answers
5k views

What challenges needed to be overcome to create (blue) LEDs?

In light of today's announcement of the 2014 Nobel laureates, and because of a discussion among colleagues about the physical significance of these devices, let me ask: What is the physical ...
2
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0answers
46 views

How would we see the earth if refraction of light was significantly stronger?

On worldbuilders there is a question about the cosmological consequences of a world with super-high refraction and atmosphere opaqueness. I'm assuming the easiest way to minimally change the laws of ...
2
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1answer
33 views

What are the 'types' of parametric down conversion?

I'm looking at photon entanglement, and everywhere in the literature there's a reference to 'type-II' parametric down conversion as a source of entangled photon pairs. I know what parametric down ...
2
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0answers
50 views

Clarification about Bragg's law explanation

The Wikipedia has this illustration of Bragg's law and then says The two separate waves will arrive at a point with the same phase, and hence undergo constructive interference, if and only if ...
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2answers
55 views

How to Ray Trace Chief and Marginal Rays in Thin Lens Systems

Looking at the below images, the chief and marginal ray appear to be modeled just fine. But, those lines don't seem to conform to the rules typically used in thin lens ray traces. An example of ...
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21 views

Reflectance and Wavelength

I want to create a graph of reflectance versus wavelength (reflectance spectrum- for example http://en.wikipedia.org/wiki/Distributed_Bragg_reflector#mediaviewer/File:DBRREFL.JPG) for a mirror but I ...
4
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1answer
53 views

How do mirrors look & behave atomically?

I was observing mirrors recently and I was thinking about how an mirror would look atomically. I was always used to looking at atoms as being colored that said, I was always concerned at how they ...
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0answers
14 views

why an immersion lens is called so in Ion Optics?

In Ion Optics, an immersion lens is composed of two planar apertured electrodes. My question is why it is called an 'Immersion" lens? I know that an Einzel lense has three or more electrodes. But ...
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2answers
34 views

Sellmeier Refractive Index of Standard Air

The question: What is the Sellmeier description of the refractive index of air at some reasonable temperature, pressure, and water content? The description must be in the following form:$$ ...
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0answers
11 views

Explanation of fringe pattern of thin film interference

Recently i went through calculations for finding the path difference between the first 2 reflected rays for a oil film with air on other 2 sides .But i could not understand how the fringes will be ...
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1answer
41 views

Is fluorescence from a single atom/ion visible with the naked eye (e.g. in a strongly coupled trap or cavity)

I remember sitting in on a conference talk by a person (possibly Rainer Blatt) doing research with trapped ions (or single atoms strongly coupled to light in an optical cavity), and the person showed ...
6
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2answers
373 views

Homemade Spectrometer

Recently I have had ideas of how to build a spectroscope, but I'm not sure if it will work. As can be seen in the diagram, the experiment is simple: it consists of a laser that generates the light ...
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1answer
48 views

Keplerian Telescope Exit Pupil Location - Whats the Basis for It's Formula?

For a simple two lens Keplerian telescope, this is the formula for the location of the exit pupil: $$z'=\frac{f_2}{f_1}(f_1+f_2)$$ Where $z'$ is the distance to the exit pupil location (i.e. eye ...
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2answers
46 views

On solving a two lens system

A common method to solve for the image formed due to a two lens system consisting of two thin-lenses separated by a distance is: Locate the (intermediate) image formed by the first lens, ignoring ...
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0answers
24 views

Fresnel lens magnification, convex divergence

Is it possible to use a series of lenses to divert some of the energy output of a large Fresnel lens to two distinct focal points?
2
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0answers
45 views

Conceptual question on helmholtz equation

Given the homogeneous Helmholtz Equation $[\triangledown ^2 + \kappa^2] E= 0$, I understand $\kappa$ represents the wavenumber $\omega_0 / c$. In light of this, what physical meaning can be taken from ...
3
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1answer
32 views

What is a vectorial vortex beam?

I know that a Laguerre-Gaussian (LG) beam with topological phase non zero has helical wavefront, but still linear polarization. So if LG beams are not vectorial vortices, what could they be?
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1answer
30 views

Diffraction and Shape in the grating

Suppose, I use a laser with a known wavelength of 650 nm through a "opaque grating" that has a pattern of holes of same shape and size. We can see the pattern on the screen. We know the distance ...
1
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3answers
78 views

What “exactly” happens when a ray is incident at the critical angle?

The question arose when my physics teacher taught me geometrical optics and told that the phenomenon of both refraction and $reflection$ occur by change in medium. First of all, I'm not sure about the ...
1
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1answer
51 views

How does 1/f come out as the intercept when plotting a graph of 1/u and 1/v in convex lens?

On this link, in the convex lens second method to calculate focal length. I did not understand how the graph of 1/u and 1/v can give 1/f as the intercept? Could someone please explain?