Questions tagged [photonics]
Photonics is the science of creating, moving, and detecting photons
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Induced Electric field in metasurface
In CST Microwave Studio, for metasurface simulation, the defined electric field for the incident linearly polarized plane wave is 1 V/m. However, the induced electric field for the unit cell of the ...
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Michelson interferometer but with 1 arm (Part 2)
I designed a setup similar to Michelson Interferometer but with one mirror only. So, there is an angle between the 2 rays to the detector:
In order to understand the result on screen, I used (Zemax/...
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Does the creation operators for photons with different polarization commute?
Let $\hat{a}^{\dagger}_{\sigma}$ be the creation operator of a photon with the polarization $\sigma $ towards some reference. What are the commutator relations for the creation operators of a photon ...
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Is luminescence from impact of fast neutral atoms/molecules on a suitable substance known?
Cathodoluminescence is emission of photons by electrons impacting on a luminescent material.
The Rutherford scattering experiments detected impacting helium nuclei on a phosphor screen.
Many other ...
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Photonic classical and quantum computing
How different is the hardware used for classical and quantum photonic computers? Are there any proposals on hybrid platforms? I'm curious why I never heard of both within the same context, except for ...
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How can the inverse of stimulated emission be distinguished from "normal" absorption?
A simple system with two energy states can absorb an incoming photon (of adequate energy) to get excited, and it can relax by either spontaneously emit a photon afterwards or get stimulated by another ...
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Interferometer designed to create diffraction in free space
I designed the following interferometer:
If the light beam -theoretically- is very narrow , will light be diffracted away from point B from QED's perspective?
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Destructive interference pattern perpendicular to photon's propagation direction
I'm studying the interference pattern for light. For example, the following is the interference pattern for double slit experiment:
I'm curious to know if there is an existing interference pattern ...
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What happens if obstacles (walls) been put where destructive interference occurs in double slit experiment?
If photon doesn't have probability to be in dark (destructive interference) area, what will be the effect of adding obstacles (walls) in the dark (destructive interference) area for the double slit ...
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Inconsistency between Jones vectors and Stokes parameters
Plane wave equation :
\begin{equation}
\vec{E}(z,t)=\left| \begin{array}{c}
E_{0}^{x}e^{i\delta_{x}} \\
E_{0}^{y}e^{i\delta_{y}} \\
0 \\
\end{array}\right|e^{i(\omega t -kz)}\quad,\quad E_0^{x,y}
\in\...
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Is IR Emissivity changed by being submerged in fluids other than air?
I am aware that IR emissivity happens in a vacuum, but treating vacuum as the best case rather than the worst case (where there is nothing adjacent to an emitting atom/surface).
Where should I start ...
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Collection efficiency of mirror
I want to compare plane and parabolic mirror for collection of photon from a point source. Intuitively, parabolic mirror focuses all rays from point source and gives parallel rays therefore has a ...
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Encoding information on photon qubit
I study QKD which relies on the single photon as a qubit, on which information is encoded.
There are many protocols which mainly differ on how information (bit) is encoded on the qubit :
polarization ...
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Does the beam image invert on each round-trip through a hemispherical laser cavity?
When one creates a hemispherical laser cavity, using one flat and one concave mirror, does the beam image invert each time it makes a round trip? I know when passing through the focus of a lens/mirror,...
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Tightly-focusing a single photon
I'm curious about the feasibility, both theoretically and experimentally, of tightly focusing (or spatially trapping) a single photon to guarantee its precise targeting. If it’s possible, isn’t it ...
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The expression of photocurrent
Consider an electro-magnetic field represented in phasor notation $E_0e^{-jwt}$ incident upon a photodetector/photodiode, what is the expression of the generated photo-current $I(t)$? Here $E_0e^{-jwt}...
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How to get good visibility in Single-photon_interference?
This question is specific to the experimental quantum optics community. I am attempting to perform a Mach-Zehnder interference experiment using single photons as a source. However, I am encountering ...
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How to rotate the polarization of photons?
What device is used to rotate photons from H to V. Does it change the energy of the photons? I heard about half wave plate?
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Can there be two different physical units (or dimensions) for a same physical quantity?
I was going through this book "Nonlinear optics" by Robert W. Boyd for my postgraduate subject in Nonlinear optics and I came across the different orders of nonlinear susceptibilities. From ...
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Mode Interferometers (MMI) versus waveguide couplers
In Photonics Integrated Circuits Mach-Zender (MZ) modulators are very often used. This design splits one wageguide into two spatially separated waveguides and makes them to rejoin, in order to ...
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Are there any nonlinear crystals or other transparent materials that can produce anti-Stokes, phase matched, frequency shift of laser light?
While some nonlinear crystals can convert incoming laser light into harmonics, thus for example doubling the light frequency, are there any crystals or other transparent materials that can reduce the ...
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Photon as a qubit
I am studying Quantum Key Distribution which relies on photonic qubits, the photon.
Indeed, this one is viewed as a qubit, that is a two state system, just like the
spin of an electron, an atom with ...
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Transmittance of one material through a multilayer
Good morning,
I have the transmittance and the reflectance spectrum of PET (Polyethylene terephthalate) and I also have the transmittance and the reflectance spectrum of PET + Copper (50 nm). I would ...
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Why does Near Infrared (NIR) light allow deeper imaging in biological tissue in Multiphoton Microscopy?
I have been reading this paper on multiphoton microscopy (https://www.nature.com/articles/nphoton.an.2010.2) and I am very confused about something. Here is a quote from the paper:
"The NIR ...
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What is a true delay line and is there possibly a false delay line?
I'm reading "Silicon nitride passive and active photonic integrated circuits: trends and prospects" and one of discussed application of $\rm SiN$ is "true delay line". All the ...
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Missing Scaling Factor of the Electric Field of Hermite-Gaussian Modes
I am currently looking at A. Yariv's book "Introduction to Optical Electronics" 2nd edition. In Chapter 3 "Propagation of Optical Beams in Homogenous and Guiding Media", Yariv ...
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What's the difference between a rhombus lattice and a hexagonal lattice in photonics?
I am learning photonic crystal slabs. I try to figure out what the difference between a rhombus lattice and a hexagonal lattice in photonics is?
All I know is that they have diffefent Brillouin zones,...
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Waveguide allowed modes | Transverse resonance condition
Consider a planar waveguide for example. The guiding index is $n_f$, and the cover and substrate indices are $n_c$ and $n_s$ respectively. Let the waveguide propagate along z, and have a height $h$ in ...
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Effective Refractive index of a mode less than that of the cladding refractive index?
Can the effective refractive index be less than the cladding if the waveguide width is very small. For example for the case of a ~100 nm waveguide.
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Non-Linear Crystals (BBO) splitting photons
So from what I've studied till now about Photon Entanglement is that when we input a photon of a particular wavelength ($\lambda$) into a BBO crystal (a non linear $\chi^2$ crystal), it has a ...
