Optics and Photonics - Science topic

I was wondering if the problem has to do with the introduction of Time as a fourth dimension. In the metric introduced by Minkowsky in his paper SPACE AND TIME, with the complex plane, it is possible, to define a minimum Basic Systemic Unit, based Euler's relation that has the most remarkable property of remaining the same in spite of change, so it is a mathematical expression of a Quantum, so that "spooky action at a distance", is not the point in this case, as a Quantum does not change, as it constituted by two Totalities that cannot be separated, they are joint in the complex plane in a indivisible unit, just as that ancient Taoist Symbol(Yin-Yang) as was found in the Ottawa University in their experiment of with the Quantum entanglement.

For those interested in that experiment about Quantum entanglement in the Ottawa University you can find it:

and here you can find the correspondent paper

Interferometric imaging of amplitude and phase of spatial biphoton states - Nature Photonics

Edgar Paternina

Upcoming Events "CONFERENCES" in Berlin, Germany |October 24-26 2025.

Recently, I have been working on photonic sensors, and my latest project involves an innovative design for a cancer detection sensor using a photonic ring resonator structure in a label-free setup. In biosensors, three key parameters determine sensor quality: Sensitivity, Quality Factor (QF), and Figure of Merit (FOM). My unique optimization approach has resulted in approximate values as follows:

Additionally, the structure achieves an impressive FWHM of 0.003 nm. For comparison, ideal ranges for these parameters typically are:

As the saying goes, “every achievement has its cost,” and there are always trade-offs in design. The high QF and FOM in my design highlight exceptional sensor performance, although the Sensitivity remains within an average range. Given these results, I am interested in feedback from the community—do you think these results are promising enough to submit for publication in journals focused on photonic sensors?

Your insights and suggestions would be greatly appreciated!

I am interested in defining the heterogeneity and similarities among metalenses and their advantages in the current and new applications, and identify some of their future improvements and characteristics.

Which one is better regarding loss, stress, roughness for photonic and optical applications at 1330 nm and 1550 nm wavelengths.

Smart photonics is a new technology that uses the combination of photonics and artificial intelligence. This technology uses light to transmit information at high speed, increase the efficiency of communication and data processing systems, increase processing speed and reduce energy consumption. Smart photonics is used in various fields such as optical communications, optical sensors, data processing, medicine, energy and environment, security and protection, etc. By integrating the power of photonics and artificial intelligence, this technology can significantly improve the performance and efficiency of various systems and devices. What do you think about the advancement of photonic efficiency based on artificial intelligence?

In the structures of combined rings, it is difficult to have completely symmetrical rings due to the delay in response time. Also, it is very difficult to reach a quality factor above 5000 in these sensors due to the wide response pulse width. Can anyone help me in this field (designing the combination of rings) to reach a quality factor above 15000?

thank you

A primary difference between photons would be:

Radio waves (3 kHz to 30 GHz) have lower frequencies of all types of EMR, and their photons carry less amount of energy. Interactions with matter depends on wavelength and energy density and create EM charges with absorption or emission.

Microwaves (30-300GHz) don’t bend (diffract) around hills or mountains, they don’t reflect back from the ionosphere (Micu, 20230). With higher frequency, microwaves penetrate more than RF waves transmit data over wireless networks, to communicate with satellites and spacecraft.

I am wondering what tools people use to design these circuit layout schematics in 3D (as shown below).

I know illustrator can do some of this but what else is used for 3D designs of complex photonic/electronic circuits?

Figure References:

1. https://cemse.kaust.edu.sa/ipl/system-level-applications-integrated-chip-lasers

2. Bogaerts, W., Pérez, D., Capmany, J. et al.Programmable photonic circuits. Nature 586, 207–216 (2020). https://doi.org/10.1038/s41586-020-2764-0

Hello everyone

I'm trying to program the eigenmode expansion method to calculate EM field propagation in photonic integrated devices such as input/output spotsize converters. I wrote a FDFD mode solver and am now trying to normalize all the optical modes found by the mode solver. There are no problems with guided modes and some unguided modes (I use integration by trapezoidal rule, the limits of integration are defined by calculation window). Could you recommend some articles or books where I could find information on how to numerically normalize all the modes that FDF modesolver finds, or some practical recommendations?

Thank you and have a nice day!

optical losses

need a brief answer wrt the question mentioned above

I am looking for lumerical script code for generation of such large data set for deep learning of Photonics devices.

Does anyone have the PDF manual of the Till Photonics Polychrome IV monochromator? We cannot find the manual online and we would really appreciate any help!

photonics integrated circuits (PIC) theories and practices are very highly recommended in P.R.China right now. Can someone kindly raise some courses, materials and other stuff related to the subject?

Thanks.

I am looking for a FAB that can make InP based photonic integrated circuits based on provided custom design, please help me to find one?

Somewhere in china or asian countries will be better

We have an open postdoc position

Regards

I am working on topology optimization for photonic devices. I need to apply a custom spatial filter on the designed geometry to make it fabricable with the CMOS process. I know there exist spatial filters to remove the pixel-by-pixel and small features from the geometry. However, I have not seen any custom analytical or numerical filters in the literature. Can anyone suggest a reference to help me through this?

Thanks,

I use Fujikura CT-30 cleaver for PCF cleaving to use for supercontinuum generation. Initially, it seems like working fine as I could get high coupling efficiency (70-80%) in the 3.2um core of PCF. However, after some time (several hours) I notice that coupling efficiency decreases drastically and when I inspect the PCF endface with an IRscope, I could see a bright shine on the PCF end facet, which is maybe an indication that the end face is damaged. Also, I want to mention that the setup is well protected from dust and there is no chance of dusting contaminating the fiber facet.

Please suggest what should be done to get an optimal cleave, shall I use a different cleaver (pls suggest one) or there are other things to consider.

Thanks

As you know, the refractive index of a specific material is a function of wavelength. This phenomenon is called dispersion. The Sellmeier equation is an empirical formula for calculating the wavelength-dependent refractive index of a particular transparent medium. For common optical material, the refractive index is computed with 6 sellmeier coefficients (B1,2,3 and C1,2,3). Unfortunately I couldn’t find these coefficients for CR-39, or allyl diglycol carbonate (ADC), in databases that are available in literature (even in Schott Glass and Ohara catalogues).

Hi there!

I have a question:

What is the best photonic network on chip simulator which has a good manuals and learning and community?

best

Yasin Asadi

Hello everyone, I need some channel models MATLAB code to simulate my Underwater Visible Light Communication algorithm. If anybody has some models then please provide. thank you.

Here you can talk and share your idea and experiences on network on chip simulators in any fields like Wire, Wireless, 2D, 3D, Photonic, etc.

feel free to ask questions and share ideas.

what is the best simulator in this field and what makes it better than others?

when we introduce a defect layer in the middle of the photonic crystal (binary, ternary, or any other structure) a resonant mode appears somewhere within the photonic bandgap. I have noticed that the FWHM of these resonant modes decreases as the number of cells in the photonic crystal increase! Anybody knows why!

Hi, I am new to this and trying to design a waveguide at 850 nm. So I simulated the structure in Lumerical for different core sizes. These three graphs(attached) are the results I got for mode 1( which I think is a fundamental mode). How do I conclude the result, should I choose the core size for which TE fraction is 1? How TE/TM ratio and other parameters will affect the optimization process? Also I'd like to know how optimization process will differ for single mode.

Thanks for reading. I really appreciate any suggestion.

What are the advantages of using SiO2 substrate over Si substrate for monolayer graphene in photonics?

Both for 1330 nm and 1550 nm

I am currently trying to simulate a THz metastructure in CST studio using the frequency domain solver. I would like to know if it possible to change the field strength of the incident radiation. TIA.

As a result from the collaboration with Fabrice Raineri at Centre de Nanosciences et Nanotechnologies, Sylvain Combrié and I are proud to introduce the first Optical Parametric Oscillator made of a 20 by 5 microns photonic crystal cavity. With a power threshold as low as 50microWatt and a combined slope efficiency approaching 50%, it might stimulate new results in the field of integrated photonics, including quantum technologies. You can find details here:

Marty, G., Combrié, S., Raineri, F. et al. Photonic crystal optical parametric oscillator. Nat. Photonics (2020)

https://rdcu.be/ccydc

“The interaction of a field with a thin scattering layer corresponds to multiplication with a diagonal matrix“

Original from：Wetzstein, Gordon, et al. "Inference in artificial intelligence with deep optics and photonics." Nature 588.7836 (2020): 39-47.

What effect does the height of the dielectric rods on the photonic crystal (three dimension) have on the photonic band gap? (Could height cause high displacement in the photonic band gap range)

What effect does increasing the radius of the rods in three-dimensional mode have on the band gap gap?

Hello

Why using a radius with 5 μm in the waveguide at photonic integrated circuits while a radius with 7 μm has minimum loss?

Dear All

I lead a special issue in Photonics (SCIE indexed; Impact Factor 2.140).

The aim and scope of the special issue is "Photonic devices and systems". I would like to invite you to submit a paper for this special issue. Your outstanding participation will be interesting for many readers. Thank you!

Cheng-Yang Liu

Associate Professor

Department of Biomedical Engineering

National Yang-Ming University, Taiwan

https://www.ym.edu.tw/cyliu66

Hello Dear Researchers, I am confused about the Difference between Second-harmonic generation and Two-photon absorption? Can anyone describe the two phenomena briefly in the physical picture? What is the difference in measuring them?? Thanks a lot.

#Photonics #Optics #Physics #Nonlinear Optics

Hello,

I have started reading about photonics circuits, and most papers I read about this devices I noticed that they are designed to operate single mode instead of multi mode. But I haven't been able to find why is this the case?

Can someone explain me or refer me to a paper where this is explained?

I have tried to regenerate the result from drude-lorentz model in the article "Ultra-broadband THz time-domain spectroscopy of common polymers using THz air photonics". The dielectric number of PA6(figure 2 below). my result is very similar to the results but are not equal. I have multiplied both oscillator strength and resonance frequency in 2*pi but the damping coefficient has not been multiplied.

in both COMSOL and MATLAB my results are similar but are different from the article. I think the problem must be about the coefficients in table 2 of the paper.

I am trying to model a photovoltaic device using AMPS-1D software. But once I am submitting it to queue, it remains there for infinite amount of time without giving the result.

I couldnt understand what is the problem. Kindly please help me out.

Thank you in advance.

Dear Colleagues,

I'm studying the optical limiting effect in organic material due to reverse saturation absorption. As we know, in reverse saturation absorption, the transmission coefficient decreases as the intensity increases, or the absorption coefficient increases as the intensity increases, resulting in power loss. So, when we increase the laser power to a threshold P0, there are two competing processes: the increase in input power and the power loss due to reverse saturation absorption. If these two processes are in equilibrium, the optical limit curve is horizontal (as in the attached pictures.) However, if the amount of lost power is greater than the increase in input power, the curve must go down at P0. Why in the paper on optical limiting don’t we  see such cases?

Thank you and hoping for your insightful response.      

Hello! Colleagues, what resource do you use to monitor conferences on fiber optics and photonics?

I was trying to simulate a dielectric slab with epsilon=4 and Miu=1 and conductivity =0. My objective is simply to get reflected and transmitted spectra following the Fresnel’s equation for normal incidence. The simulation setup is as follows,

solver: Time domain

boundary condition: along x and y open boundary, at zmax open and at zmin open(add space)

port: waveguide port 1 at Zmin (this port is in the background medium, which is normal or air) and waveguide port 2 at Zmax (on the dielectric end)

Simulation range in wavelength: 1.45 to 1.65.

Wave generating at port1 incidents at the dielectric from the normal/ air medium.

post processing: optical; calculate reflectance, transmittance, absorbance.

Result: absorbance is between 0.9 to 0.93 while reflectance and transmittance are very small.

I can‘t understand why absorbance is so high as the conductivity of the dielectric is zero.

please help me.

BER analyzer parameters meaning.

I want to synchronize two lasers,but one of them has a large intrinsic jitter (Nd:YAG) which is troublesome.

I want some easy ways to reduce that jitter below ps.

I would like either know if injection seeding can reduce this jitter?how?how much jitter reduce will I have(approximately)?

If some one can give me some helpful reference,it would be so nice.

Thanks so much for reading or answering.

Sepideh Ghaffari

How to measure the photonic efficiency of a photoanode in the PEC system?

Has anyone worked with .vws Till Photonic image files in python? Are there libraries or other ways to extract TIFF images from them directly in the script?

Hi ! Good Evening to all :)

As of Im doing my research in photonic studies particularly in study of Optical Microring Resonator of 2D implementation by using the COMSOL Multiphysics 5.5 , I might wanna seek for opinion regarding certain of my result , is it I'm doing it the correct way to design it ? or is it im approaching the correct way to design it ?

Thanks ! :)

Thanks.

Can anyone tell the response time of Kerr-nonlinearity of Silicon and SiO2? And which material have quickest response time?

Various colorimetric assays we use are blue/purple/pink/red but not in green shades. Is there any particular reason for this?

This question is more in regard to the resonant structures used for sensing applications, namely surface plasmon resonance, photonic crystals and guided-mode resonance based devices, etc which all show a spectral redshift on increasing the refractive index of the top region. I don't remember coming across photonic structures wherein the spectral resonant response blueshifts as we increase the top refractive index. Is it possible for a structure to do so? And if not, why?

We want to estimate the accuracy of the Hufnagel Valley (HV) model using measured refractive index structure parameter (C_n²(h)) data.

Does anyone know if there there is any C_n²(h) data publicly available somewhere?

Dear colleagues,

I am investigating the dependence of the number of diffraction rings on the concentration in third order non-linear organic dyes (due to nonlinear refraction and nonlinear absorption). Prof. Pramodini [1] claims that the number of diffraction rings depends linearly on the concentration. However, Prof. Hussain A Badran [2] assume that the number of rings increases exponentially with respect to the concentration. Our experimental curves on aniline blue and Acid blue 29 showed a linear relationship. However, for Oil Red O, experimental curve is not the straight line and the exponential curve. So, is this relationship linear or exponential?

Thank you and hoping for your insightful response.

1.S. Pramodini, P. Poornesh, Effect of conjugation length on nonlinear optical parameters of anthraquinone dyes investigated using He –Ne laser operating in CW mode, Optics & Laser Technology

2. Badran, Hussain A.; Ali Hassan, Qusay Mohammed; Imran, Abdulameer, A Quantitative Study of the Laser-Induced Ring Pattern and optical limiting From 4-Chloro-3-methoxynitrobenzene solution, Basrah Journal of Agricultural Sciences . 2015, Vol. 41 Issue 2, p51-57. 7p.

The very common experiment in optics to demonstrate that light behaves same as the wave is single-slit diffraction.

If we assume that the thickness of the barriers is 0.1 mm, then the length of a slot along the optical axis will be a long route as a green photon will measure it nearly two hundred times larger than its own size.

Now the question is how the photon behaves along with that long route? Does it behave as a particle or wave? If the exit of the slot or a pinhole is causing photon behaves as a wave then why the entrance wouldn't do that? And if we accept that photon behaves like a wave as it enters the single slit or the pinhole, then formally we should apply the Fresnel diffraction equation from the entry of the slot that will lead us to nowhere.

In my opinion, wave-particle duality is leading us solely to some useful approximation but it doesn't talk about reality, as it cannot explain a sort of experiments that unfortunately have been ignored or left behind such as the glory of the shadow, and also the stretching the shadows when they meet each other and so on.

For sure, wave-particle duality is not the end of science and for sure five hundred years later people will not consider the existence as do we do now the same as us that we don't see the things same as our ancestors, so we should be open-minded to be able to open the new horizons.

I need the INTERCONNECT software for simulation of photonics integrated circuits.

Hi dears

I want to do the absorption of a structure for the wavelength range of 280 to 900 with the desired divisions. For example, I want the wavelength distance in this case to be 0.5 nano, in other words, it returns the absorption information every 0.5 nano.

Lumerical(FDTD) apparently does this for random wavelengths. But I want to get the absorption for wavelengths of 280 to 900 nano, at distances of 0.5 nanometers.

In other words, in the image below, I want the value of "value", 0.5 Nano 0.5 Nano change.

Is there a way to do this in Lumerical(FDTD) ?

Thanks in advance for your reply.

Motahari

comment

The analysis of the " Nanocomposites in optoelectronics and photonics " research topic is here

https://www.researchgate.net/project/Research-topic-map-analysis-review/update/5e7dd3deb9f8cd00019a3c26

Notions, subtopics, basic knowledge and articles potentially with novelty

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Срок исполнения 1-4 дня.

Темы для анализа принимаются на почту v.m.kugler urfu.ru

или

прийти Мира 19, Главный учебный корпус, Б-105

Dears,

I hope u r good.

I m looking for papers on optical/photonic waveguides for O band (1310 nm).

Can u plz help in citing a good literature?

Regards

Faisal

Optical chopper is a frequntly used device. It modulates CW signal to pulses. Mathmatically, when a CW signal is converted to pulses, it introduces new frequency sidebands. How is it possiable to generate new optical frequencies in a linear mechnical process? If it is true, what could be the physical mechanism?

I am ICP etching AlGaAs Bragg structures using Ar, Cl2 and BCl3.

After etching (typically a few microns), there is material deposited on the surface and sidewalls of my photonic structures. I assume it is something like AlCl3... but I'm not sure.

I want to remove this deposited material as it increases the roughness.

I have tried H2O2, up to ~20% concentration, but this does not seem to help.

Does anyone know what the deposited material is, and how could I dissolve it away?

How can i check that the Circular polarized beam is Right-handed or Left-handed? I use a Quarter-wave plate to make the circular polarized beam. I don't mind any method.

UV-Vis spectrophotometer has a light detector that detects photons by current signals. But the detector itself cannot differentiate between a high energy photon (short wavelength) and a low energy photon (long wavelength). It can only measure the number. However, if we require the irradiance or power per unit area, we have to multiply the number of photons with the energy of the photons. Does the UV-Vis spectrophotometer show the power per unit area or number of photons?

My guess is that it shows the power per unit area because the Mie analytical spectra for plasmonic nanoparticles agree with UV Vis spectra.

What type of PCF is ideal for coherent SC generation for carrier envelope offset measurement of a modelocked laser. As far as I know, for coherent SC generation, PCF should be pumped in normal dispersion regime. Moreover, PCF should have ZD (zero dispersion wavelength) close to pump wavelength. Are there any other conditions to consider. Plz advice.

Hi,

I am trying to perform co-design and co-simulation of the electronic-photonic interface for optical splitter and an electro-optic data modulator. Please help me with the simulation methods that can be used for this purpose.

After recording the speckle contrast, next step is to measure it quantitatively and accurately. I am not sure how many pixels of an image should be considered for its calculation. Speckles were recorded under dark room condition.

It would be great if someone can tell from his/her experienece or recommend me a research paper about this specific issue. I searched but i was unable to find any papers or research work related to it.

Thanks in advance!

Hello dear researchers,

I want to measure the value of the third-order nonlinear susceptibility (Chi3). I have only the third harmonic generation (THG) spectra in photon counts and I know the input power at the sample to be probed. In literature, people used some materials whose Chi3 is already known and after comparison, they gave a rough estimation of chi 3. The other way in the literature was used is the utilization of an additional laser to calibrate the power.

I would like to ask is there any other way to measure the output power or chi 3 value? any simpler way if you know the input power and output intensity in photon counts???

I want to overlap the Cs atom with a nanofiber. I am using two cameras but it is still not clear. So I added an external coil to AH coils to move them flexibly. Now the issue is how to minimize the external magnetic field!!!

We have LG¹₀ beam only and we have to get HG(1,0).

Dear professors and colleagues,

I am going to to study effect of the two photons absorption in Safranin O. Safranin O is organic material, so I think that the power needed to activate this effect doesn't need to be too high. However, the two photons absorption is a third-order nonlinear optical effect, so it is usually implemented with high-power pulsed lasers. I cannot afford to buy high-power pulsed lasers. So, can I stimulate effect of two photons absorption in safranin O by continuous wave laser (808 nm or 1064 nm)? And how much is the required power of laser? I hope the colleagues who have experience in this experiment share me useful information.

I look forward to hearing from you. Thanks in advance.

Yours sincerely.

Dear Colleagues,

I am investigating methods to determine the photodynamic activity of photosensitizers for photodynamic therapy. One of the methods being used is absorption spectrometry. A work concludes that significant absorption of light was shown to be prerequisite but not sufficient for high photodynamic activity. My point of view is: When a photosensitizer absorbs more radiation at a certain wavelength, it will produce more Ros (Reactive oxygen species), i.e the absorption maximum will correspond to the wavelength active photodynamic effect best. However, this point of view contradicts the viewpoint in above work. I look forward colleagues to explain this question.

Thanks in advance.

In the semiconductor laser, I have an equation (attached) that shows the relationship between optical gain and the number of carriers in a laser. In this equation I have a parameter by name of gain cross section.

I want to know the physical concept of that is.

Hi all,

I am attempting to implement 3D finite difference (FD) beam propagation method (BPM) based on alternate-direction implicit (ADI) method.

Does anybody know about how to implement or the formulation of transparent boundary condition (TBC) in 3D FD-BPM based on two step ADI method?

Any suggestions or advice would be appreciated,

Thank you!