A research field within general optical physics concerned with light and its material interaction: where light is modelled by full quantum mechanical description.

learn more… | top users | synonyms

1
vote
1answer
30 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 ...
1
vote
1answer
11 views

The DLCZ Protocol

I have been reading the article review for Optical Quantum Memory (http://arxiv.org/abs/1002.4659) when I came across this section about DLCZ protocol. I don't understand about Beam splitter. For what ...
7
votes
3answers
172 views

Runge Kutta Method for a Lindblad Equation

I am solving a Lindblad equation for a dissipative Harmonic Oscillator. My Hamiltonian is time dependent, My Lindblad Equation can be written as \begin{equation} ...
0
votes
1answer
543 views

Stark effect in two level atomic, laser-driven system?

In a two level atomic system (Rabi oscillating problem) the perturbative potential is oscillating / sinusoidal because it comes from the electric field from the laser. Now stark effect is the ...
0
votes
0answers
43 views

What is the transpose of the displacement operator? [closed]

How do we calculate the transpose of this expression? $$ \hat{D}(\alpha) = \exp \left( \alpha \hat{a}^\dagger - \alpha^* \hat{a}\right) $$ What is the simplified result? Displacement Operators: ...
1
vote
2answers
36 views

Why does a single mode fibre have a cutoff wavelength?

I earlier had a doubt based on ray theory that light must reflect and so all wavelengths should propagate through SMF. This Q/A Single-mode fibers and ray-theory of light does specify that we have to ...
1
vote
0answers
26 views

Radius dependence of Energy levels of spherical Quantum dots

I have frequently read in articles that the energy level of spherical quantum dots depends on radius. We simply match the wave functions inside and outside the particle and find the intersection of ...
0
votes
1answer
55 views

Ultrafast photon detectors

Are there already photon detectors that can resolve the shape of photons in the time domaine if it looks like below where the two humps are separated by a time of the order of femtoseconds? What I ...
0
votes
2answers
24 views

If I have created a polarization-entangled photon source, would I be able to create a qubit?

In my laboratory, I have already obtained a polarization-entangled photon source. It was created via the Spontaneous Parametric Downconversion process of 2 BBO crystals. The next question is that ...
0
votes
1answer
16 views

Optical devices for micro meter photons?

Are there all the common optical devices like beam splitters, mirrors, polarizers, fibers, etc for photons with a wavelenght in the range of micro meters? If so, how broad can the bandwidth be for ...
2
votes
1answer
45 views

Paraxial wave equation solution?

I am looking for a worked solution to the paraxial wave equation, since most sources just say that clearly Gaussians are solutions but they do not explicitly show so. This equation is equivalent to ...
0
votes
0answers
26 views

Two-photon absorption and 3rd order susceptibility

I am referring to introduction of Section 12.5 Multiphoton Absorption and Multiphoton Ionization (Page no. 550 of Nonlinear Optics, Boyd-3rd edition) where it has been said that the two-photon ...
4
votes
2answers
50 views

What is the difference between surface plasmon and surface plasmon polariton?

I'm trying to understand this reading article linked below and I still don't know how to explain this simply, without need to derive everything mathematically. Can someone just write here how do SP's ...
3
votes
1answer
149 views

First order coherence through double slit

The state $$|\Psi \rangle = |0\rangle + \sum_j \int d\omega f_j(\omega)\hat{a}^\dagger_j (\omega) |0\rangle $$ is coming from a far field and incident on a double slit setup. Here j is the index of ...
3
votes
2answers
589 views

Is single photon perfectly monochromatic?

Now, we do have equipment to generate single photon at a time, and LASERs are nearly monochromatic. While typing the question, am realizing that successive photons in case of single photon ...
1
vote
0answers
20 views

Cut angle for BBO type I SPDC

I am using an old BBO crystal, which is not designed for spontaneous parametric down conversion, to see whether I can generate converted photons of 800nm from 400nm. I used a photon avalanche detector ...
0
votes
1answer
80 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 ...
22
votes
4answers
322 views

Why doesn't a typical beam splitter cause a photon to decohere?

In many experiments in quantum mechanics, a single photon is sent to a mirror which it passes through or bounces off with 50% probability, then the same for some more similar mirrors, and at the end ...
0
votes
2answers
39 views

the frequency of the white light

A white light, as we all know, is composed of seven lights VIBGYOR. Each of the component lights has distinct frequency ranging from one value to another. So, when the photons have wavelength of 600 ...
2
votes
2answers
81 views

Normalization of photon wavefunction and beam splitters

I am having trouble with the normalization of photon wave functions, when passed through a beam splitter. Let me define the single photon state as $$|1\rangle = \int \text{d}\omega \phi(\omega) ...
0
votes
1answer
74 views

Photon detection rate for pure / mixed states coming from single mode point source

Let the pure states be in superposition of horizontal and vertically polarized basis states. They are arriving at the point detector one at a time. So, a pure state is $|\Psi\rangle = \alpha|V\rangle ...
3
votes
1answer
40 views

Off-diagonal terms of the Husimi $Q$ function?

The Husimi $Q$ function of a quantum state $\rho $ is defined as $ Q (\alpha)=\langle \alpha \vert \rho \vert \alpha \rangle $, where $\alpha = (x, p) $ is a phase space coordinate and $\vert \alpha ...
2
votes
2answers
55 views

Mean free path of a photon in a fiber

Is there a way to calculate, or a reference table I can to look up which provides the average distance a photon travels before it encounters an electron and is absorbed or re-emitted in a fiber optics ...
0
votes
1answer
53 views

Omega-frequency or pulsation?

I'm reading a book about optics in English. However, I speak a different language and have a problem with distinction. What does $\omega$ mean? $\omega=1/T$ or $\omega=2\pi/T$ What is the ...
0
votes
1answer
36 views

Conservation of probability in Jaynes-Cummings model

I was reading about Jaynes-Cummings model. I've studied Bachelor level QM. In the interaction picture the solution with rotating wave approximation and initial conditions $C_g(0)=0$ and $C_e(0)=1$ is ...
0
votes
0answers
22 views

coincidence counting by stanford dual sr400

I am an amateur of experimental physics, and I would like to use a Stanford dual sr400 counter to make the photons coincidence counting to see quantum optical effects. Right now I am about to set up ...
2
votes
0answers
38 views

Electron momentum distribution and wavefunction in momentum space

Does there exist any relationship between the electron momentum distribution used in above threshold ionization and the wave function in momentum space? In other words, starting with the wavefunction ...
0
votes
0answers
12 views

Temporal coherence in Computational ghost imaging

In pseudo-thermal ghost imaging using a laser beam passing through a rotating ground glass plate, the temporal coherence is important since the intensities in both scanning and bucket detectors have ...
1
vote
0answers
27 views

Continuous Variable Entanglement Measure for the Statistically Mixed State

Can anybody tell me, which is the best entanglement measure for the Continuous Variable Entanglement of a Statistically Mixed State ? I have read that Schmidt decomposition is not valid in this ...
1
vote
1answer
222 views

In terms of covariance matrices, are partial measurement and partial trace equivalent?

Partial measurement and partial trace There is a connection between a measurement of a part of a system and tracing this subsystem out. Say, we have a system composed of subsystems $A$ and $B$ in a ...
0
votes
0answers
37 views

Polarizing beam splitter

I'm searching for basic literature or papers introducing the action of polarizing beam splitters with single photons. Unfortunately the most books and papers only focus on usual beam splitters. The ...
2
votes
2answers
33 views

Photon dispersion in an optical fiber

What is the law of spatial dispersion of a photon in an optical fiber? Say I have a femto second photon ($\lambda$ around $700\,\text{nm}$) with gaussian shape ($\sigma = c\cdot 1\,\text{fs}\approx ...
0
votes
0answers
17 views

Numerical Computation of Linbald Equation

Can anybody suggest me a good algorithm for the time evolution of the reduced density matrix using Linbald equation. My Hamiltonian is time dependent. I am aware about Qotoolbox and Qutip. I have ...
8
votes
1answer
271 views

A moderate introduction to Hanbury Brown Twiss interferometry in particle physics

For astronomy, as originally invented, the Hanbury Brown Twiss interferometer is good for finding the angular diameter of stars and is not a rapidly fluctuating observable like the amplitude in ...
3
votes
1answer
32 views

Color of macroscopic objects on molecular level

Macroscopic objects either reflect, or transmit, or absorbs electromagnetic waves. Assume now we have, say, a red apple exposed to the usual white light. The red light is apparently reflected from ...
3
votes
2answers
43 views

Are all fluorophores dipoles?

Lately I'm reading about surface enhanced fluorescence. In many articles I can see that fluorophores are called "dipoles". Is it because that they can be modelled by a vibrating electric dipole? Or ...
3
votes
1answer
119 views

Shot noise at high frequencies (can it really be ideal white noise?)

Quantum shot noise (either optical intensity noise or electrical current noise) described by the noise spectral density of $2 e I$ (electrically) or $2 h \nu P$ (optically). So it is white noise. I ...
0
votes
0answers
21 views

Exhaustive list of assumptions for the Clauser-Horne-Shimony-Holt inequality

I am trying to create an exhaustive list of all assumptions which work as the base of the CHSH inequality. Locality - this means an object can be influenced only by its surroundings. So, the events ...
0
votes
0answers
38 views

Proving two forms of atom-field interaction perturbation Hamiltonian are equivalent

In the presence of an electromagnetic field in the dipole-approximation (${\boldsymbol A} = {\boldsymbol A}(0,t)$) we have the two forms $$H_{{\boldsymbol d}\cdot {\boldsymbol E}} = - q {\boldsymbol ...
0
votes
3answers
84 views

What happens when one of the photons in entangled state gets destroyed?

Consider two entangled photons with two mutally conjugate circular polarization. What happens when one photon which is, say, left hand polarized gets destroyed. Will the other photon retains its right ...
4
votes
3answers
679 views

Lasing in a 2-Level system?

What exactly is the difference between 2-Level, 3-Level and 4-Level systems? Why can we not achieve stimulated emission in a two-level system using optical pumping?
4
votes
3answers
362 views

Beam splitters and Mach-Zender interferometers

I have a question (my very first here) related to 50/50 beam splitters as used in the Mach-Zehnder interferometers (see for example http://en.wikipedia.org/wiki/Mach-Zehnder_interferometer). Let's ...
1
vote
1answer
56 views

Do beam splitters work for very broad photons? (frequency bandwidth, spatial extent)

If I send a single photon through a usual beam splitter, is there a limit for the beam splitter to work properly related to the photons broadness in frequency or in space? For example a femto second ...
3
votes
1answer
99 views

Wave function of a photon?

consider a single photon. Since it is not possible to create a photon with a certain frequency it can be characterized by a normalized frequency distribution $f(\nu)$ that is peaked around some mean ...
2
votes
1answer
61 views

What are “parity considerations” in deciding the form of the Hamiltonian?

In "introductory Quantum Optics", by Gerry and Knight, the Jeynes model is considered. In this model of electron-EM field interaction the electron is approximated by a two state system ($\lvert ...
3
votes
2answers
70 views

How is the set of displacement operators best called?

Displacement operators $\hat D(x,p), \ \ x,p\in\mathbb{R},$ follow a composition rule $$D(x,p) D(x',p') = \exp\frac{i(px'-xp')}2 D(x+x',p+p').$$ Because of the extraneous phase factor, the set of all ...
3
votes
1answer
78 views

What low-level process drives a frequency-doubling crystal?

I was reading about second-harmonic generation (SHG) crystals (or frequency-doubling crystals) used to produce green laser light from IR. What low-level process in the crystal is actually driving ...
3
votes
1answer
82 views

Polarization in Lasers and Liquid Crystal Displays

When we talk about Polarization in Lasers we mean placement of the crystal at Brewster angle to block the s-polarization and only the p-polarization will survive. How do we compare the term ...
5
votes
1answer
1k views

What IS reflection?

How does quantum electrodynamics actually explain HOW reflection occurs on a microscopic scale? Note that Feynman's QED lecture series/book is not sufficient, as he only assumes that light DOES ...
0
votes
1answer
25 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 ...