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
20 views

Has anyone developed tunable notch filters in the visible RGB wavelengths which have very fast response times?

I am interested in whether the combination of a spectrometer and a tunable notch filter with notch frequencies at the visible red, green and blue wavelengths which have very fast response times could ...
1
vote
0answers
33 views

Rotating a Gaussian Beam

I need to see how the phase fronts of two gaussian beams interact when they intersect with each other. The two beams are tilted towards each other so that they intersect each other at their respective ...
1
vote
0answers
19 views

Optics - Derivation of Linear Magnification of Lens without Sign Convention [duplicate]

In some posts in this forum I've read that sign convention in optics is useful for making formula memorizing easier, and that we have to use sign convention again while applying the formulae to ...
2
votes
1answer
30 views

Reflection from multiple thin films: accounting for lost light due to small surface area

I have a problem similar to reflection of multiple thin films. I have light coming in from medium 1 and I want to find the total reflected intensity after being reflected inside 2 layers. However, I ...
0
votes
0answers
9 views

Transmission of porous membrane with vertical cylindrical pores

There is some porous dielectric membrane with strictly vertical cylindrical pores. I would like to find theoreticaly optical transmission spectra of this membrane, depending on the bulk material ...
8
votes
3answers
3k views

Why does the sky look black in pictures taken from the summit of everest?

In pictures taken from the summit of Mount Everest (such as this one), the colour of the sky is a very dark blue or even black in some pictures. I remember from my own experiences of hiking in the ...
0
votes
1answer
45 views

Helicopter wings

Why do the propellers on helicopter appear to be so slow when the propellers is going at full speed? Can you please explain this particular optical illusion to me?
2
votes
1answer
36 views

Fringe Pattern Brightness for Young's Double-slit experiment

Perhaps I have missed something in my notes, but I have noticed when looking at different sources that some textbooks/sites state that the fringe brightness for the young's experiment is the same for ...
1
vote
1answer
54 views

Does this photograph portray double muon impact with nanogold atoms?

1PHOTO 1: Macro-photograph of an NIH/FDA TEM of a nanogold dark stained biological sample projected onto Silver Halide (AgX) photographic gel paper. On June 10 I questioned if PHOTO 1 ...
0
votes
0answers
10 views

What kind of mirror do i should use for rear projection? [on hold]

i have around 11 inch to make a rear projection for a 94 inch screen. i have tried with a convex mirror (half dome mirror) but the aberration is too blurry on the sides, so i don't know what kind ...
1
vote
1answer
56 views

Black holes: Behaviour of light near an event horizon

Electromagnetic waves travel mostly in vacuum medium, in outer space, but sometimes in gaseous media, such as in gaseous atmospheres involved in nebulae. If electromagnetic-waves come anywhere in the ...
11
votes
2answers
1k views

Car headlights glass - why such uneven shape/texture?

Why does the glass on my car's headlights have such a strange shape/texture? Are there physics-based explanations or insights for these features? Wouldn't it be better if it was just transparent and ...
0
votes
1answer
84 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 ...
3
votes
0answers
38 views

Output of a beamsplitter with photon number (Fock) state inputs

Given a beamsplitter drawn below, where $\hat{a}$ and $\hat{b}$ are input modal annihilation operators, transmissivity is $\tau\in[0,1]$, and output modal annihilation operators are ...
2
votes
1answer
23 views

Color in Different media

When a light wave passes from one medium to other, the wavelength of the light wave changes and the frequency remains constant. If then color of the light waves depends on changing wavelength or ...
1
vote
2answers
49 views

Frequency difference of absorbed and emitted photons?

In a transparent medium, how does the frequency of incoming light compare to the exiting light? I thought it was the same, but doesn't there have to be an energy difference in two electron states in ...
0
votes
0answers
12 views

Short clips with transcripts about interesting physical phenomena [closed]

I want to use of some interesting short clips with their transcripts at physics related to fundamental physics or quantum mechanics or physical phenomena. Can any user guide me?
2
votes
1answer
43 views

Relationship between Polarizability and Conductivity

I've seen in the literature the relation: $\sigma (q,\omega) = \frac{i e^2 \omega}{q^2}\chi(q,\omega)$ where $\sigma$ is the conductivity and $\chi$ the polarizability. However my attempt to derive ...
5
votes
2answers
298 views

How would an X-ray mirror work?

I was wondering if light can be reflected how can someone reflect X-ray of what material does it need to be made of and is its design completely different to that of our original mirrors? Does this ...
0
votes
0answers
28 views

Deriving the Laguerre–Gaussian equation [closed]

How does one derive the Laguerre–Gaussian equation? $$ x\frac{d^2y}{dx^2}+\left(1-x\right)\frac{dy}{dx}+ny=0 $$
0
votes
1answer
24 views

Trouble understanding phase matching equation

consider a 2nd order non linear optical material, i.e. a material in which it holds that $ P = \epsilon_0 E + 2dE^2$. In the Born approximation, the non linear contribution to the polarization density ...
2
votes
3answers
146 views

Is it feasible to detect light emitted from planet earth 2,000 years ago by reflection from an object situated 1000 light years away?

The possibility though remote, is intriguing as we may be able in the future to actually "see" our own planet's history. Though sounding science fiction, if we are able to detect bodies in space that ...
3
votes
1answer
70 views

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 ...
0
votes
0answers
20 views

What is the way to make a semi-transparent object to appear white? [closed]

Can an object appear opaque white to the eye but still be transparent ; i.e. pass light through (like a one-way mirror effect) In other words, is there any other way for an object to appear white, ...
1
vote
0answers
20 views

What happens if we use an optical fibre for light at a different wavelength than the one specified on the fibre?

Say the fibre is for 700 nm, and we shine light at 1064 nm into it. Would it change the mode? The polarisation? The beam shape (i.e. introducing ellipticity in the beam)?
1
vote
1answer
45 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 ...
0
votes
0answers
24 views

Propagation of light from a point source in seawater [closed]

If the light intensity of a point source (480 nm) is 1.09 x 10-8 Wm-2 at a distance of 1 m, what would that intensity be at a distance of 0.005 m in seawater? I have used the Beer-Lambert Law to back ...
6
votes
2answers
87 views

At Interfaces Does Light Have to Accelerate?

First, I'm not sure if photons have to "get up to" the speed of light, or if they are thrown into existence at that speed. I know that they should just be generated moving at their speed, and I know ...
4
votes
1answer
127 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
votes
2answers
173 views

Double-slit expirement fundamentals (half-silvered mirror version)

In the double-slit experiment variation in which 2 half-silvered mirrors and 2 mirrors are used to illustrate the interference of a stream of photons or single photons at a given time step, how is it ...
0
votes
1answer
122 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 ...
1
vote
1answer
31 views

Thin Film Interference in Fluid Dynamics: Many are welcome to throw ideas in here, Please!

It was a few days ago, and there was a very heavy storm(currents were flowing beside the sidewalks as normal). I became intrigued by a thin film of gasoline that got caught in one of the currents. The ...
0
votes
1answer
16 views

How to block coupling between adjacent waveguides?

I have a number of nonlinear waveguides, say six. I don't want coupling between specific two waveguides. Other than keeping them large distance away, what are the other possibilities to ensure no ...
0
votes
1answer
58 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 ...
0
votes
0answers
54 views

Understanding the mathematical formulation of the Faraday effect

The Faraday Effect is a magneto-optical effect which results in the polarisation of light being rotated I would really want to understand the theory of this, but I only have a basic EM knowledge, ...
7
votes
1answer
778 views

How to turn water opaque by pouring the smallest quantity of matter into it? [closed]

Consider a glass of water and a glass of coffee. Their contents differ by no more than a few grams of particles coming from the roasted and ground coffee, yet the former lets almost all visible light ...
4
votes
2answers
2k views

How does the grid on the microwave oven window prevent microwave radiation from coming out?

If I look through the microwave window I can see through, which means visible radiation can get out. We know also that there is a mesh on the microwave window which prevents microwave from coming out. ...
1
vote
1answer
26 views

What will be the effect of placing a light source very close to a photodiode?

What will be the effect of placing a photodiode really close to a laser source and what should be the appropriate distance between a light source and photodiode to get maximum output current?
1
vote
1answer
38 views

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

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
votes
2answers
255 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 ...
1
vote
3answers
77 views

Can light be trapped theoretically?

My question is a little silly I know, but I'm curious to know if a particle of light can be theoretically trapped between two reflective screens. For example once the particle of light has left it's ...
1
vote
1answer
87 views

Has the photon both gravitational and inertial mass?

The theory of relativity shows that the inertial mass of a body increases with the energy it contains; if the increase of energy amounts to $E$, the increase in inertial mass is equal to $E/c^2$, ...
1
vote
2answers
251 views

Why does heterodyne laser Doppler vibrometry require a modulating frequency shift?

On the wikipedia article (and other texts such as Optical Inspections of Microsystems) for laser Doppler vibrometry, it states that a modulating frequency must be added such that the detector can ...
2
votes
1answer
44 views

Total internal reflection and waveguides

I'm looking at a model of a planar dielectric waveguide along the lines of this picture: For the wave inside the $n_1$ dielectric slab to totally internally reflect $\theta_M$ needs to be smaller ...
0
votes
3answers
75 views

Can you explain Fermat's Principle to me?

The textbook(F.A.Jenkins and H.E.White Fundamentals of Optics) states that the Fermat's principle is that the path taken by a light ray in going from one point to another through any set of media ...
3
votes
1answer
48 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 ...
0
votes
1answer
50 views

New focal point of converging light through a concave lens

Suppose I pass rays of already converging light through a concave lens. The rays are equally centered on the lens such that the original focal point is through the lens and centered on the lens axis. ...
0
votes
0answers
32 views

Which Optics textbooks are good? [duplicate]

After September,I will be a sophomore.During the vocation, I am learning optics by myself. And I learn it by reading Ajoy Ghatak's ...
0
votes
0answers
39 views

Frequency of a photon as related to the change of its frequency

I think that bob maybe already, at least partially, has answered my following question: "Is it true or false that the frequency of a photon is not related to the change of its frequency caused by ...
2
votes
1answer
178 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 ...