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

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Is the master equation appropriate for a single system?

The master equation (Lindblad equation) describes the evolution of the density matrix of a system. Since it is a density matrix, so inherently, it describes an ensemble instead of a single system? In ...
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29 views

Light (Laser) operated optical switch

I have searched the web and found that optical switches are activated either through mechanical or electro/magnetics. Making them sort of Optomechanical or optoelectronic switches. Lets exclude ...
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Unitary transformation problem [on hold]

In some of the books of quantum optics, it has been said unitary transformation change the basis along with preserving the inner product. that means, $H'=U^+HU$ where $U=\exp ix_mH/\hbar$ Here, ...
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154 views

Obtain the Lagrangian from the system of coupled equation

In this particular paper, "Interaction between a moving mirror and radiation pressure: A Hamiltonian formulation" by C.K.Law, PhysRevA.51.2537 \begin{equation} ...
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85 views

Thought experiment on light accumulation

Consider an object which is a spherical one-way mirror, and let's call it the "Sphere". For the needs of the thought experiment, suppose that: the Sphere is perfectly spherical the mirror is ...
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Ramsey pulse versus optical pumping: what's the difference?

A Ramsey pulse is a coherent process, where the electronic states of for example an ion (or some other two-level-system) are coupled to a laser field. By tuning the laser precisely, we can coherently ...
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What degrees of freedom (other than polarization) of a photon can be used to store quantum information? [duplicate]

Usually in quantum optics, one uses the polarization degree of freedom of the photon to create and manipulate photonic qubits. This, using various linear optics devices, can be coupled with the 'path ...
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The Longest Storage Time of Electromagnetically-Induced-Transparency-Based Quantum Memory

Do anyone know any paper that demonstrate the longest storage time of quantum memories protocol based on EIT achieved experimentally? I have tried to look for it on Google but find nothing.
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65 views

How to Derive Atomic Hamiltonian and Cavity Hamiltonian?

In a Fundamental of Quantum Optics and Quantum Information book which I am reading, it states without explanation that, in a two-level atomic configuration in a cavity system, the Atomic ...
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correlation function of coherent states

Hey folks, I got a question regarding the correlation function of coherent states. Which of the following states are n-degree coherent, i.e all g_n are equal to one. The first one is something ...
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34 views

Quantum correlation functions of the electric field

the first order correlation function for one mode (up to normalization) is definied as: $$g^{(1)}=\langle a^\dagger(t) a(t+\tau) \rangle$$ The second order: $$g^{(1)}= \langle ...
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Quadrature in quantum optics

I am reading a chapter about Squeezed state, and came across this word, quadrature, which I have never seen before in the book. Here is the quote from that chapter. " A general class of ...
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Recommended books that describe emission and absorption of light and light/matter interactions

Hello I am a Chemical Engineer that has ventured into the field of optics and I was wondering if there is any recommended book/books to understand the maths and also some answered exercises or ...
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38 views

Determining path of light through a nanolens

In the case of light passing through stacked liquids, we can use a ray approximation of the path of light to determine the path taken through each layer of liquid using Snell's law. From all the ...
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26 views

What is the meaning of coherent decay rate and population decay rate?

In quantum optics, especially the part when talking about atom-light interaction, there are two different kinds of decay rate, coherent decay rate $\gamma_{ij}$ where $i$ and $j$ are atomic energy ...
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Quantum optical master equation

In Quantum Noise by Gardiner and Zoller (p. 86f) they derive and write a version of the quantum optical master equation. $ \dot{\rho}_S (t) = -\frac{i}{\hbar} [H_\mathrm{sys} ,\rho_S] - \sum_m ...
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Verdet Constant and optical pumping

While studying Faraday rotation (linear magneto-optic rotation) I came across a fact that faraday rotation can be enhanced. Verdet constant which depends on the wavelength can be enhanced as change in ...
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Creating an arbitrary state of the quantum simple harmonic oscillator

Suppose $\mathcal{B}=\{|0\rangle, |1\rangle, |2\rangle, ... \}$ is the energy eigen-basis of a quantum simple harmonic oscillator. I want to create the state \begin{equation} |\Psi\rangle = ...
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52 views

Does spontaneous emission actually emit in a random direction, or is it measured in a random direction?

When an excited state couples to the vacuum, it has an infinite number of directions of the quantized electromagnetic field to couple to. Does it evolve into a superposition of all those directions at ...
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Quantum beam-splitter matrix

I have seen the matrix for the action on a quantum beam splitter described in one of two ways: $$\begin{pmatrix} t_1 & r_2 \\ r_1 & t_2 \end{pmatrix}$$ (this appears in Quantum Optics by ...
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40 views

Superscript on density matrix

I have been asked in homework to solve the optical bloch equation for the initial condition of $\rho_{22}=0,\rho_{12}=0$. Professor gave a hint of the general equation and let us carry it from here. ...
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decoherency of number states

The meaning of decoherency is: When a nonclassical state, transitions to a classical state. It means that the state lost it's phase information. I can't understand how it happens in number states.
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Is local oscillator light polarised?

If a laser is used as a local oscillator in the homodyne setup does this mean the light it produces is polarised? (I am looking at this from the context of quantum physics and random number ...
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75 views

I want to solve Mathieu Equation $y''(x)+(a−2q \cos(2x))y(x)=0$. How to solve it using Floquet solution?

I want to solve Mathieu Equation $$y''(x)+(a−2q \cos(2x)) \, y(x)=0.$$ How to solve it using Floquet solution? In Floquet solution for integer order of $v$ and $π$ periodicity We have Solution ...
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57 views

Mach-Zehnder interferometry wave functions

Consider the set up below: I have read that in the apparatus the wavefunction is given by: $$|\psi \rangle=e^{i\theta}|c \rangle +i |b \rangle$$ where $\theta$ is the phase added by the phase ...
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44 views

Oberving a photon through double slits

If we send a particle with mass through the double slits we observe a interference pattern. That is of course if we don't observe which slit the particle goes through. If we do then we get two peaks ...
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One-axis squeezing scalling derivation

In a paper by Kitagawa & Ueda Squeezed spin states they give an argument that the minimum variance in one-axis twisting Hamiltonian scales like $V_{min} \propto S^{-2/3}$. I will shortly describe ...
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Associated photon field of a two state system

Given the time-dependent density matrix $\rho(t)$ of a driven two-state system $\mathcal{S}$. How do I calculate the time-dependent quantized photon field that would be generated by transitions in ...
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41 views

Colour of certain objects

How do internal structural bandgaps define object colour? For example, if an object is transparent, are the energy bandgaps in the structure too large for even the 400 nanometer photon to be able to ...
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51 views

In the photon picture, how can light slow down and yet not be absorbed? [duplicate]

Many materials, such as glass, are transparent over some wavelength interval. In the photon picture, as far as I understand it, this is because there are no allowed transitions corresponding to the ...
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114 views

What is the difference between QED and quantum optics?

What is the difference between QED and quantum optics? Once you have QED, you have not only the quantized EM field, but also the interaction between matter and the EM field. So, you should have ...
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Is my window's semi-transparency a consequence of elementary quantum mechanics? [duplicate]

Studying mathematical concepts of quantum mechanics, I have recently become familiar with the classical model of one-dimensional particle being scattered by a potential barrier. As a mathematician, I ...
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1answer
73 views

Entanglement of coherent states

I am new to quantum optics and I am trying to understand whether coherent states of the field could be entangled. Let's consider, for example, a two-mode state: $|\psi^{AB} \rangle = \frac{1}{c} ...
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Is there any review paper on spatial light modulator?

I need a review paper on the various types, principles and characterization of spatial light modulator. But it seems I could not find one. Any one has a good idea?
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How does light manage to change its course at the boundary of two media of different optical densities?

This is a conceptual question. I already know the law of refraction but I need something like an idea of the Physical process from both particle and wave theory standpoints. Why does a ray of light ...
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61 views

Single particle passing through the double slit at a time [duplicate]

In modern experiments, With the classical setup of photons or electrons passing through double slit, the intensity is kept extremely low, such that one can detect a single particle passing through ...
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82 views

Do photons emitted from a LED show bunching?

If photons are emitted from a thermal source, we get photon bunching. For coherent radiation, the detection probability doesn't change after detecting a photon. For single photon sources, we get ...
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When was Electromagnetically Induced Transparency first introduced?

The oldest paper I know regarding this topic was published in 1997 by Stephen E. Harris. But I am not sure if he is the first to introduce this idea. Could you tell me when and by who did introduce ...
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Any suggestion of laser pointer for everyday life study of fluorescence?

I want to buy a laser pointer to study fluorescence in my kitchen. Any suggestion? What kind of laser pointer? What stuff for demonstration?
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Why the plots of a second-order intensity correlation function appear both Bunching and Antibunching?

This second-order correlation function is calculated based on a single atom in a cavity, driven by classical light source,under the condition of two photons resonance. When I plotted it in ...
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Classical and semi-classical vs quantum interferometry

What is the difference between classical, semi-classical and quantum interferometry? How the detectors look like? As far as I know in classical interferometry light is treated as a wave, whereas in ...
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Refractive index for matter waves

What is the relation for a group velocity of matter waves with refractive index of general medium? Google will tell you the answer but majority of them are related to experimental work for a specific ...
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67 views

How many photons are absorbed during Rabi oscillations?

In my understanding, Rabi oscillations are derived using the classical approximation for the electromagnetic field. I don't get how this picture fits with a quantized EM field though. Say you excite a ...
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91 views

Time-dependence of ladder operators in quantized EM fields

My Question Are the operators for the $A$, $E$ and $B$ field to be treated as operators in a Heisenberg description or is their time dependence explicit when performing a textbook EM quantization as ...
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82 views

Phase shift of the displacement operator

According to my professor, the displacement operator $D(α)=e^{\alpha a^†−α^*a}$ can be written, "with a simple phase shift", as $D(α)=e^{i\alpha(a^†+a)}$ which he then proceeds to write as ...
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90 views

How does a laser emit light in a coherent state?

Lasers work by stimulated emission of atomic transitions. Stimulated emission produces two photons which, because the particle number is well-defined, projects the field into a Fock state. However, it ...
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Are the Wigner and Husimi transforms injective?

I am wondering if the Wigner function is injective. By injective I mean, that, for every density matrix $\rho$, there is a different Wigner distribution. The same question applies to the Husimi ...
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How can a photon have a frequency but not a phase?

When a single photon is emitted as a result of relaxation of an electronic energy level, it (the field) is clearly in a Fock state because it has a well-defined number of quanta. By the uncertainty ...
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doppler cooling temperature limit

Wikipedia shows a heating effect that causes minimum temperature achievable in doppler cooling as: "The atom performs a random walk in momentum space with steps equal to the photon momentum due to ...
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Why is the frequency bandwidth of the environment important for Markovianity?

In the derivation of Spontaneous Emission in two level systems in Quantum Optics (be it Wigner Weisskopf or a different approach, such as density operators to find the master equation), one makes ...