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

15
votes
0answers
242 views

Are the fast axes on Thorlabs quarter-waveplates mislabeled?

Some members of my lab are performing a polarization-sensitive experiment where they need to use a quarter-waveplate (QWP) with the fast axis in a specific direction. In the process of carefully ...
8
votes
0answers
97 views

mode-locking a laser on prime-powers' frequencies

Being rather a theoretician than an experimental physicist, I have a question to the community: Is it experimentally possible to mode-lock a laser (fixed phase relationships between the modes of the ...
5
votes
0answers
89 views

Optical mode leakage through a layer of gold

The geometry of my semiconductor device is given below. The blue regions are gold, the grey ones - gallium arsenide (n-doped to $2.9 \times 10^{15} \mathrm{cm^{-3}}$). The dimensions are μm, i.e. it ...
5
votes
0answers
181 views

Suntan: UV absorption vs daytime

I guess that these questions were being asked by many people on the Northern Hemisphere during this summer (and other summers) and someone may give a nice, coherent answer. The general question is how ...
4
votes
0answers
98 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 ...
4
votes
0answers
57 views

Light, Fourier Transforms, Spherical Harmonics

Mathematically, I'm having trouble understanding where we can use what with light. I read somewhere on this site that Huygen's Principle is effectively just taking an expansion of a wave onto the ...
4
votes
0answers
68 views

Blonde hair looking green at certain angle

I have a friend who has blonde hair. And when look at an oblique angle, there's a tinge of light green in her hair. I've heard that the copper ion in pool water can make blonde hair green, but her ...
4
votes
0answers
44 views

How does a microscopes optics expose defects in the users vision?

I've got cataracts in both eyes. My vision is correctable to 20/30, so the cataracts are essentially a non-issue in daily living. But when I use a microscope, which I do daily, (binocular, zoom ...
4
votes
0answers
76 views

Optical Bloch Oscillation

I have a doubt about how the optical Bloch oscillations happen in a 1D photonic crystal. I try to explain: in a photonic crystal with discrete translational symmetry in one direction I superimpose a ...
3
votes
0answers
44 views

Entanglement g-2-experiment - Which components do I need?

I would like to measure whether my source emits entangled photon pairs. To that order I want to build a g-2-experiment, which measures photon coincidence counts as a function of time delay between ...
3
votes
0answers
64 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 ...
3
votes
0answers
74 views

Mathematical approaches to atmospheric refraction

Understanding atmospheric refraction, particularly of ultraviolet, and into the blue part of the visible spectrum is of great interest to me. Although, I have a strong background in trigonometry and ...
3
votes
0answers
89 views

Superposition principle and polarization

I am reading an optics book (Physics of Light and Optics by Peatross and Ware) that asserts this: A beam of light can always be considered as an intensity sum of completely unpolarized light and ...
3
votes
0answers
119 views

Maximum-Entropy Method deconvolution implementation?

I am looking for an implementation of the Maximum Entropy Method for image deconvolution, ideally in MATLAB or Mathematica. I'm trying to reconstruct an image from fringe visibilities, as is often ...
3
votes
0answers
232 views

Pockels effect/Kerr effect

In Pockels electro-optic effect, change in Electric field produces change in refractive index/ birefringence. Moreover this effect becomes electric field squared in the case of Kerr effect. If we ...
3
votes
0answers
1k views

How does autorefractor work?

Autorefractors are being used by eye opticians for eye diagnosis. I searched internet for articles and wiki page as well but I wasn't satisfied. I am interested to know how do they actually work. How ...
3
votes
0answers
50 views

SHS Interferometer and diffraction limit

I'm currently researching Spatial Heterodyned Spectrometers (SHS) and I'm a bit at a loss understanding the influence of the diffraction limit. I'll be measuring a diffuse visible light source with ...
3
votes
0answers
135 views

Bandgap Spacing in Photonic Crystals

I am doing some self-study on photonics and have encountered the following question: We know that amorphous electronic crystals such as amorphous silicon have a bandgap. Can amorphous photonic ...
3
votes
0answers
67 views

A problem concerning the change of temperature and spectrum of a filament

The spectrum of a filament has been given before, the left one having the lowest temperature, the middle with a medium temperature and the right one with the highest. My question is this: Why does ...
3
votes
0answers
183 views

Is it possible to calculate the work function of a metal with basic lab equipment?

ive been given a problem in physics, its to prove if a lump of metal we have been given is real gold or not. one way to to do it would be to work out its density, which is fairly easy, mass/volume. ...
3
votes
0answers
80 views

Optics: finding total power of a syste, including wavelength

Specifically I need to create an ABCD matrix given 2 radii of curvatures, the thickness of the lens, type of glass (BK7) and a given wavelength. I will have to figure this out eventually, so help ...
2
votes
0answers
35 views

What is the relation of scattering, extinction and absorption cross sctions with scattering parameters?

In optics and electromagnetics, they frequently calculate the extinction, scattering or absorption cross sections of a single particle (e.g. a sphere). Scattering cross section which is the ratio of ...
2
votes
0answers
32 views

Why isn't Zemax showing a tilt on the wavefront on my telescope design?

Attached is a Zemax file Zemax File for an afocal telescope system. When i tilt the field by an angle of 2 degrees (In green) I would expect a wavefront tilt at the "Image " plane, however when I ...
2
votes
0answers
16 views

Circular diffraction onto uneven surface

I'm trying to figure out how to solve for a surface using a circular diffraction. I have a pinhole diffraction that I'm projecting into a surface and I'm trying to figure out how to derive the shape ...
2
votes
0answers
33 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.
2
votes
0answers
50 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
votes
0answers
54 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 ...
2
votes
0answers
48 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 ...
2
votes
0answers
122 views

Effective refractive index calculation of fiber core

Can someone pls explain what is effective refractive index of fiber core and how to calculate it theoretically? Suppose the fiber core refractive index=1.4446 and cladding refractive index is= ...
2
votes
0answers
39 views

Expectation value for the time of a photon reflection

A photon is reflected by matter (by an electron in empty space). How long does the reflection take? (i.e. is there any infinitesimal time elapsing during the reflection process?), or more precisely, ...
2
votes
0answers
42 views

How is the imaginary part of angular frequency omega related to the imaginary part of the refractive index?

I'm trying to find the attenuation constant (leak rate) $\alpha$ from the imaginary part of the refractive index of a lossy material. I have the eigen frequency $\omega$ for my structure which has an ...
2
votes
0answers
51 views

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 ...
2
votes
0answers
49 views

Is TRUE invisibility possible?

First off, this question may seem highly stupid at first, but it arose from past cartoon memories. In the cartoon Tom & Jerry from the 1940s, there was already hypothesizing over cream that, when ...
2
votes
0answers
49 views

caustics on droplets on glasses formed by streetlights

Suppose you're out at night, and it's rainy, and your glasses are covered by water droplets, and you chance to look at a streetlight. Are the ridged caustics of light seen at the edges of these ...
2
votes
0answers
47 views

Determine laser cavity modal content from beating / interference?

I'm trying to better understand the modal content and dynamics of laser cavities. I'm specifically interested in mode-locking, although this question is pretty general and applies to CW lasers too. I ...
2
votes
0answers
54 views

What is the requirements from an optical lab in terms of darkness

I am characterizing an optical lab and would like to know therefore what are the requirement from a standard optical lab in terms of ambient luminescence. In other words how dark should an optical lab ...
2
votes
0answers
208 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 ...
2
votes
0answers
181 views

Optical Raytracing by using Adiabatic Hamiltonian Method

I'm looking into raytracing a Lüneburg Lens which is a gradient index (GRIN) optical element with a radially varying refractive index: $$ n(\rho)=n_0\sqrt{2-\left(\frac{\rho}{R}\right)^2}, ...
2
votes
0answers
71 views

Laser Transverse/Longitudnal Modes

When we say Laser transverse modes. Is that mean what we will get at the output spot of laser beam ? secondly In practice , what TEM01 or TEMnm means ?
2
votes
0answers
70 views

Collimating and homogenizing a divergent tunable-spectrum light source

I have a light source (Xenon lamp) which has the possibility to be tuned over spectral range of 390 - 740 nm with 1 nm spectral accuracy . Bandwidth at each wavelength is about 20 nm . Output ...
2
votes
0answers
105 views

Line-shape asymmetry in undergraduate Hydrogen-Deuterium experiment

I'm working as an LA (undergraduate TA) for an undergraduate physics laboratory experiment where students test the Bohr model and use reduced mass to determine the approximate mass of the neutron. In ...
2
votes
0answers
116 views

Why is Erbium Doped Fiber Amplifier (EDFA) preferred over Erbium Doped Waveguide Amplifier (EDWA)?

Why is Erbium Doped Fiber Amplifier (EDFA) preferred over Erbium Doped Waveguide Amplifier (EDWA)? The question has been asked from an engineering point of view, but obviously I would also be ...
2
votes
0answers
466 views

How does a Fresnel rhomb work (half and quarter wave plate)?

How does a Fresnel rhomb work (half and quarter wave plate)? I am aware of birefringence, which creates a phase shift of $\Delta\phi=\dfrac{2\pi\Delta nL}{\lambda_0}$. But this doesn't explain how a ...
2
votes
0answers
232 views

How to calculate radiative transition rate of exciton in a quantum dot with specific dimension?

I am writing rate equations for a nanophotonic system including three quantum dots. I need to calculate that radiative transition rates of exciton in ground state in those quantum dots. In the paper ...
2
votes
0answers
65 views

fiber optic second order PMD as an operator on the tensor product Hilbert space

Second order polarization mode dispersion (SOPMD) is a coupling mechanism between polarization and frequency. Take our photon to be the following tensor product: $\psi = \int \gamma_{\omega} | ...
2
votes
0answers
180 views

projective camera: back-projecting a point on the image plane into 3-space

suppose I got a projective camera model. for this model I would like to back-project a ray through a point in the image plane. I know that the equation for this is the following: $$ y(\lambda) = P^+ ...
2
votes
0answers
150 views

Modeling a spray painted polyurethane surface reflection

I'm modeling light interaction/reflection from a fiberglass surface with polyurethane epoxy (that is very reflective) that has been spray painted with a matte black paint. I'm looking for some input ...
1
vote
0answers
17 views

how can a lens combination take virtual object to the second lens?

When two lenses are in combination. what logic is it to take the image of first lens (which is not formed in real) as a virtual object to the second lens ?
1
vote
0answers
30 views

Increasing the volume of a object in a photograph

I have two images which look like this --- These images are two views of a calibration object --- the white die that you see hanging in the middle. The problem is that, the die is too small and ...
1
vote
0answers
23 views

Third-order dispersion of glass

When working with short laser pulses, it is important to compensate the dispersion of a pulse passing through a material because it changes the pulse's shape. The effect of dispersion can be described ...