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.

learn more… | top users | synonyms

-2
votes
0answers
10 views

Wave optics - Interference [on hold]

A lens with refractive index=1.5 is coated with a thin film of refractive index of 1.2 in order to reduce the the reflection from its surface at wavelength= 4800 Angstrom . Find the minimum thickness ...
0
votes
0answers
11 views

Limitations of (non-lightfield) near-eye displays

The answer to Is it possible to blur an image in such way that a person with sight problems could see it sharp? suggest that you cannot present a "counter blurred" out-of-focus image such that it ...
0
votes
2answers
13 views

Possibility of making an experiment in a classroom to simulate DNA diffraction

I am a TA in a structural chemistry class. The professor want me to show students how Watson and Crick determined the structure of DNA from X-ray diffraction results of DNA crystals. The professor ...
0
votes
1answer
35 views

How to convert candela into joule?

How to convert candela into joule? What equation can we use? Is this site useful? http://en.wikipedia.org/wiki/Photometry_%28optics%29
1
vote
1answer
37 views

How to treat partially polarized light with Jones vectors?

I have to calculate the degree of s-polarization (perpendicular) of a transmitted unpolarised light ray when it goes through a glass plate ($n=1.5$) at Brewster's angle (Brewster's window). ...
2
votes
3answers
37 views

Do infrared lamps provide more heat than incandescent lamps?

Infrared lamps seem to be used in situations where you want to produce heat without producing (as much) light. But incandescent bulbs also produce heat. Why not just use incandescent bulbs? My ...
3
votes
0answers
18 views

What does it mean for a Fresnel lens to have two finite conjugates?

I'm in a situation where I need to reverse engineer a product that my company already manufactures and sells, but it wasdesigned too long ago for anyone to remember. It uses a Fresnel lens with the ...
7
votes
0answers
53 views

How would a fractal refract light?

A fanciful Pink Floyd reference has led me to wonder what white light passing through an object with an infinitely complex surface would do. Would it exit from a single chaotically-chosen point on the ...
0
votes
1answer
31 views

How does airborne laser system deflect the laser beam?

In the Airborne Laser system, the laser beam is directed from the nose of a Boeing airplane towards the target. In this system, the angle of laser beam with respect to airplane body can be changed at ...
0
votes
2answers
49 views

Solution of one dimensional wave equation by variable separation method

When solving the One dimensional wave equation by variable separable method, we equate left-hand side and right-hand side to a constant which is negative in nature. Why has the constant be only ...
0
votes
0answers
15 views

Filtering UV Light to Visible Light [closed]

I'm wondering if it is physically possible to filter UV light from 400nm to 100nm so that UV light is in the visible range. If we had a UV screen over a visible range screen, could there be two ...
1
vote
3answers
49 views

Does polarization remove any of the fields completely?

A light is made up of electric and magnetic fields oriented perpendicular to each other. Can polarization lead to the removal of any of the fields completely?
1
vote
2answers
75 views

What does amplitude in wavelength of light physically mean?What oscilates with time in photon?

Like amplitude in wavelength of water waves signify the displacement of water particles about their mean position.
25
votes
3answers
3k views

How does light speed up after coming out of a glass slab?

As I learned today in School, my teacher told me that when light enters a Glass Slab it slows down due to the change in density and it speeds up as it goes out of the Glass Slab. This causes a lateral ...
0
votes
2answers
31 views

How are different wavelength components collected by the same detector in a spectrometer?

Let's think, we have a detector array (128x1 and each CMOS detector responds 400 to 1000 nm TSL1401CL that way, each detector has 4.6875 nm interval). Then, basically in a spectrometer a prism reflect ...
2
votes
1answer
51 views

Does irregular reflection form images?

In one of my test papers at school, we had a true-false question which said "Irregular reflection can form an image." I marked it true, however I was not given any marks for the question. I asked my ...
0
votes
1answer
52 views

Resolving power of ultra-telescopes

Assuming we could create and orbit optical telescopes of arbitrary size, perhaps starting with (say) inflatables or active membrane of 100m diameter what kind of resolution in imaging extra-solar ...
1
vote
0answers
31 views

Why is responsivity quoted as a figure of merit?

Lately I have been investigating the physics literature on proposed photosensitive electronic devices made of graphene. Often I see responsivity values quoted as if they suppossed to impress, and ...
-1
votes
1answer
38 views

Ways to measure the focal length of a convex lens with only natural sun light [closed]

What are the common ways to measure the focal length of a convex lens with only natural sun light?
2
votes
1answer
12 views

How to propagate a (tilted) gaussian beam through a telecentric f-theta-lens

My questions has two parts: First of all let's assume I have a gaussian beam and I send it through a telecentric f-$\theta$-lens (e.g. http://specialoptics.com/products/scanning_confocal.html) with ...
0
votes
1answer
31 views

Fresnel lens/kinoform: How to model diffraction at the edges of zones?

I would like to find the intensity distribution of light due to the diffraction at the edges of zones on Fresnel lenses or kinoforms. (That is, location of orders, heights of maxima, etc.) I can't ...
0
votes
3answers
49 views

Mirrors and the human eye

Not sure if this is a suitable question for this exchange. Me and a friend are debating what can be seen through a periscope consisting only of two 45 degree mirrors. My friend tells me that the ...
0
votes
0answers
12 views

What curved, transparent media exists for full-motion holograms?

Looking to project light either on, or through, but not from, a transparent medium. So I'm thinking of half a hollow sphere with a surface thickness of 1/10th the radius of sphere. A clear curved ...
1
vote
0answers
23 views

How to choose a type of a lens for a particular optical component?

With almost no experience in optics, I am trying to create a system that looks something like that: The idea is to be able to focus the parallel wide beam (shown in broken line between lens 214 and ...
0
votes
3answers
90 views

Is the kinetic energy of an electron always $1.6 \cdot 10^{-19}~\text{J}$?

I was doing the following problem. For $d$. They bizarrely added an extra step. They calculated the momentum of the electron to find the De Broglie wavelength using the kinetic energy relationship. ...
1
vote
0answers
16 views

Fresnel equations of reflection applied to microparticles

I wanted to know if the Fresnel equations of reflection, as described here, can be used to calculate the reflectance on the interface of particles which have a diameter near the size of the wavelength ...
0
votes
0answers
9 views

Photonic slab: 1D or 2D guide?

I have read several books that start talking about photonics wires by describing the slab guide first. Obviously, this kind of structure is a simplification of a 2D waveguide. My question is related ...
0
votes
2answers
28 views

Light intensity units in Beer-Lambert law

I have always found the Beer-Lambert law written in terms of light intensity, but what are the units of that light intensity? When related to light, some people talk about cd, or W/cm/cm... What are ...
5
votes
4answers
125 views

Light Polarizer and the Second Law of Thermodynamics

I have stumped myself with a thought experiment of my own devising. Suppose I take a beam of wholly depolarised, but otherwise plane wave light. Its von Neumann entropy per photon is $\log(2)$ nats ...
0
votes
1answer
65 views

Proving susceptibility in Lorentz Model satisy Kramers-Kronig relations [closed]

My instructor asked me to prove that the real and imaginary parts of the electric susceptibility derived from Lorentz Model satisfy the Kramers-Kronig relations using the residue theorem. The problem ...
-1
votes
1answer
41 views

Lens's diameter [closed]

This question is asked in a famous competition in my country: "Approximately calculate the diameter of the lens which this picture is taken with.(for measurements consider lens as a flat object)" Can ...
0
votes
0answers
24 views

what factors cause the “energy gap” to change between different materials?

To my understanding, every electron wants to be "excited" its next energy level. Depending on the material, the electron will need a different amount of energy to reach the next energy level. This ...
7
votes
3answers
1k views

Can I calculate the size of a real object by just looking at the picture taken by a Camera?

Can I calculate the size of a real object by just looking at the picture taken by a Camera? (I think people do that) i dont understand how?(from physics point of view)
1
vote
1answer
31 views

diffraction grating

Can I design a diffraction grating that has only two orders of diffraction, with the second one has a zero intensity? So the first order of diffraction would be bright and the weak light from far ...
0
votes
0answers
21 views

Jaynes-Cummings Model in Quantum Optics

Why doesn't JC model remain valid under the weak atom-field coupling?
0
votes
3answers
31 views

Spectrometer vs. Spectrophotometer

I have been researching about the difference of a spectrometer and a spectrophotometer. They both sound the same. What is the difference?
1
vote
0answers
22 views

If we increase the aperture of a telescope and decrease its magnification, can it be harmful to the eyes?

The full moon is the brightest object in the night sky. I believe that if we increase the aperture of the objective, and decrease the magnification of the telescope, it might concentrate a dangerous ...
0
votes
0answers
14 views

Optical density

My knowledge about optical density as a quantity is limited and I have several questions regarding it. I know that it is the optical density of a medium that determines the speed of light in a ...
1
vote
3answers
68 views

Does light change phase on refraction?

I have seen a lot about when light undergoes a phase change when it is reflected. But does it undergo a phase change when refracted and if so why and if not why not?
0
votes
2answers
36 views

Gaussian beam modelling, location of the beam waist?

In reference to the specifications of a laser diode below: http://www.thorlabs.de/thorcat/11900/L780P010-SpecSheet.pdf I wish to be able to model it as a gaussian laser beam. I understand there is a ...
0
votes
0answers
23 views

Transparent vs Insulator

Being transparent, can I say that glass is a better insulator than wood. (Reason: In GLASS visible light(lower energy)is not able to excite the electrons in it,so just pass away to other ...
0
votes
1answer
65 views

Total internal reflection for perpendicular incidence

Are there any materials, which give total internal reflection for perpendicular incidence? Here, by this phenomena I mean: no absorption (including for evanescent propagation inside), finite ...
1
vote
1answer
35 views

Lens surrounded by two different materials?

If have a material refractive index $n_1$ then a lens refractive index $n_2$ then another material on the other side of the lens (but in contract with the lens) refractive index $n_3$. How do I find ...
0
votes
1answer
22 views

Intensity for Single-Slit Interference Pattern

In the derivation for the equation for the relative intensity of a single-slit interference pattern in my textbook, there is an assumption that I find a bit fishy. I know this equation works, so it ...
2
votes
0answers
25 views

What property of medium is directly related to light propagation speed in that medium? [duplicate]

Refractive index is used to calculate phase velocity of light in medium, other than vacuum. Recently I had a discussion with somebody claiming that light is slower due to magnetic field of atoms. I ...
1
vote
1answer
32 views

Understanding camera lens and sensor compatibility

When a lens is specified not just by its focal length, but also the sensor format for which it is intended, what compatibility limits does that place on the sensors it can be used with? For example, ...
0
votes
0answers
20 views

Merging shadows [duplicate]

It is a strange phenomenon that when two shadows, say projected on to a wall, approach eachother (for example by moving the light sources closer), at some point the shadows seem to merge as if they ...
3
votes
4answers
62 views

Wave interference

Visualizing the double slit experiment, there are light lines and dark lines. The dark lines I understand are caused by the interference cancelling waves. What I don't understand is where the energy ...
0
votes
0answers
32 views

Diffraction of a thin mirror

I have a question about a particular case of light diffraction. A laser light collides into a "hairline" mirror (I mean a straight line mirror that halves the wavelength dimension), see the image ...
0
votes
3answers
48 views

Image angle illusion [closed]

I am not sure whether this question on-topic here. (please suggest to migrate if this is off-topic) What is the phenomenon/illusion (or something else?) known as where in a photo of a person, the ...