Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.

Questions tagged [optical-materials]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
1
vote
1answer
139 views

Reflectivity of metallic surfaces

Can someone please point me to an academically verified web resource/page that tabulates the Reflectivity of various metallic surfaces like gold, silver , aluminum, etc.? I have found a list on ...
0
votes
0answers
127 views

Calculation of Phase Delay of a Curved Planar Dielectric Waveguide (i.e., bend)

I am working on a very phase sensitive planar dielectric waveguide device and I need to calculate the phase delay induced by a bend of some radius, $r$ and of $\phi$ radians for a give planar ...
5
votes
1answer
187 views

Optical Retroreflectors: How Are the Faces So Accurately Righted?

This question is about Optical Retroreflectors (corner cubes) and how the extreme precision in their manufacturing is achieved. I suspect there is interesting basic physics involved, which is why the ...
4
votes
2answers
716 views

Is the visible light spectrum from “red-hot glass” at least close to Blackbody Radiation?

Briefly, for visibly transparent materials like glass, you can see through then even while they are glowing red hot. Most glasses have plenty of absorption in the IR, so there is plenty of absorption ...
0
votes
1answer
74 views

What medium could I use for a laser pointer to hit and illuminate an entire area behind it?

I'm in the planning stages of making a fun project for my nephew which will allow a wood gun with a laser pointer attached to 'shoot' at a target area. The target area will most likely be a piece of ...
0
votes
1answer
46 views

Material that reflects only a certain polarization?

Do materials exist that (significantly) reflect one polarisation of light and transmit all others?
2
votes
2answers
602 views

Why is this laser beam being scattered(and not)?

I was shining a laser beam through a liquid filled test tube(an ester particularly),and I found this phenomenon rather intriguing.Have a look. Now when I passed the laser straight through the upper ...
2
votes
2answers
2k views

Diameter of a lens vs Diameter of the circular Aperture of the lens vs Aperture of the lens

I was reading about resolving power in which it is said that "a is the diameter of the circular aperture or the diameter of the lens, whichever is smaller" . So, I don't understand how are they not ...
2
votes
2answers
4k views

Magnification vs Magnifying Power [closed]

I've read it a lot of times. But I've not been able to get around magnifying power and magnification of a simple microscope and the difference between them. Can someone explain?
0
votes
1answer
76 views

physics of color in glints

Below, I show zooms on the glints on 3 materials: (clean) metal blade, stainless sink, artificial leather (but same effect shows on human skin). Only the sink was under artificial light. What I'm ...
1
vote
2answers
241 views

Doubt on Transmittance

I have a thin film deposited on a glass substrate, when I measure transmittance (T) of it ,should I use glass or air as the reference glass or air? and why? Regarding these points: for bare glass $T=...
1
vote
1answer
330 views

Are there any CO2-Laser notch filters? [closed]

I'm searching for a notch (band-stop) filter (like [1]) for a 10.6 $\mu$m CO$_2$-Laser and I have yet to find one. Is there some physical reason such filters don't exist or is there just no demand? ...
0
votes
2answers
50 views

Enhancing of EM waves through a materal or waveguide

I'm wondering whether there are materials for which an incident EM wave would behave as $\vec E(z,t)=\vec E_0 e^{\kappa z}e^{i(kz-\omega t)}$ where z describes how far from the surface the fields are ...
0
votes
1answer
39 views

Which coefficients are needed to numerically obtain transmission spectrum?

I'm using Omnisim program. I would like to obtain transmission spectrum of certain material so I have created two polynomials: one representing real refraction coefficient and one representing ...
6
votes
1answer
267 views

Why is $\textbf{D}$ the response to $\textbf{E}$?

In the text Wooten, equation 2.69 shows $\textbf{D}$ being the response to $\textbf{E}$ with $\epsilon$ as the response function: $$ \textbf{D}(\textbf{r},t) = \int d\textbf{r}^{\prime} \int dt^{\...
2
votes
1answer
260 views

Why is GaN better than Si as a substrate for ZnO thin film?

in an attempt to grow a thin film using ZnO, I found many researches use silicon as a substrate and others use GaN. by further research I found that GaN is preferred than silicon but I don't know the ...
0
votes
0answers
39 views

Lower Threshold optical beam limiter?

We would like to implement a very fast beam limiting, so far google search shows that the common threshold ranges is in 1J/cm^2 or more, this could take seconds to activate as our laser ranges from 1 ...
1
vote
1answer
51 views

Material that changes transparency when lased from side?

I am into photonics research, and have been searching about this topic in vain, but almost nothing from Google shows up. So i turned here for some light. Do you guys know any material that changes ...
0
votes
1answer
76 views

What are the physical optical limitations photonic metamaterials can offer?

Modern technology has introduced new photonic metamaterials that can extend optical properties beyond what standard materials can offer. For example a negative index of refraction is now possible ...
0
votes
1answer
54 views

Why is Al2O3 so popular in plasmonics?

I've tried to find my own solution for this question and found out that It is cheap It is an insulator It efficiently absorbs UV Are there more properties that makes it so popular?
5
votes
1answer
321 views

Why does aluminium-on-glass mirror work without distortion?

I have read an article about glass (zerodur) with low thermal expansion coefficient. It is mentioned that large casts of such glass are covered with reflective layer of Aluminium and used as mirrors ...
1
vote
1answer
92 views

473 nm light through a single mode fiber designed to operate between 1500 and 1600 nm

Can we send light with 473 nm through a single mode fiber designed to operate between 1500 to 1600 nm spectrum? The radius of the fiber core is 4.25 micrometer, NA=0.12 and the single-mode cut-off is ...
1
vote
0answers
518 views

About Powell lens

I am a Post graduation student and I am doing a project on the conversion of a Gaussian beam into a flat top beam using optical components. I have found that the best component to do the same is a ...
4
votes
1answer
212 views

Why does the refractive index not mirror the Lorentzian peak shape of the absorption index?

In the characterization of materials, there are many methods used: One of them is infrared spectroscopy. In a lab we saw the indices of refraction and absorption of a certain (semiconductor) solid ...
3
votes
1answer
553 views

Why grating is an essential part of a monochromator?

From looking at these two images, it appears that the dispersed "rays" of the reflected light could be manipulated just as well if the reflecting mirror would be turned to a fixed angle. So why is ...
1
vote
0answers
54 views

Why does a glass acts like a mirror in viewed at an angle? [duplicate]

There is a conference hall , glass door parallel to my desk. whenever the door is open, I can see reflection of images perpendicular to the viewing angle. But when the door is closed, I can’t see any ...
1
vote
2answers
253 views

Crystal field in diamond

The crystal field effect occurs in ionic crystals and causes a splitting of the magnetic quantum levels of the cation. The magnitude of the splitting may be roughly computed by obtaining the potential ...
0
votes
1answer
2k views

Emissivity of vacuum for radiation heat

What is the heat radiation emissivity of vacuum? For air as well? What is the difference? I understand that the vacuum has reflectivity of 0, So what is the other two values are in $$ reflectivity + ...
2
votes
1answer
668 views

Plasma frequency

I have a neutral plasma and I need to solve Maxwell equations given the charge and current densities on the plasma. In order to do it I need to know the electrical permittivity $\varepsilon$, I've ...
1
vote
0answers
730 views

How to calculate the Gain of EDFA amplifier? [closed]

I have co-propagating pump laser and tunable optical signal and I want to measure the Gain of EDFA Amplifier from the Optical Spectrum Analyser (OSA). I have measured first the signal power without ...
1
vote
0answers
55 views

What is the principle behind the use of one LASER for optical pumping of Rubidium in presence of magnetic field?

How can we use a single LASER for optical pumping of rubidium in the presence of magnetic field as the zeeman levels are degenerate in the presence of magnetic field and how to decide upon the ...
0
votes
2answers
274 views

Is there a (cheap) optical resonance demonstration using visible light?

I'm looking for a impressive, inexpensive lecture demonstration of optical standing wave resonance. Preferably visible light. Can anyone suggest such a demo?
0
votes
1answer
183 views

Defects of smart glass (electrochromic glass)?

Smart glass is a type of glass that uses electrochromic mechanism to change it's light transmission properties in response to voltage, and it's made by sandwiching certain materials between two panes ...
0
votes
0answers
47 views

What are the factors affecting transparency and color of a substance [duplicate]

What is the reason behind visual properties like color and transparency of different substances? I have always heard that the structure of the substance is responsible for these properties. I always ...
3
votes
1answer
126 views

Optical signal filters

Are there any optical filters which filter the signal's frequency and not based on the wavelength of the light? So what I mean is, if I have a modulated/pulsating light signal riding on a large DC ...
2
votes
1answer
111 views

Optics, What is a Foil?

I was using a program for simulating optical elements; mirrors, gratings, foils, crystals, slits, and zoneplates are what it mentioned. Does anyone know what a foil is in terms of optics? I know what ...
3
votes
2answers
290 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
2answers
1k views

Anodized aluminium reflectivity at 10.6 um

I wonder how I can model anodized aluminium reflectivity in ray tracing-based optical simulation. I know that the parts my company is using are anodized to get covered with a ~20 um (as specified) ...
8
votes
2answers
337 views

What are the current experimental limits on the polarizability of the vacuum?

Many (all?) materials are polarizable at some level; meaning that when we apply an electric field across the material, there is an induced dipole moment $$ \vec{p}=\alpha(\omega)\vec{E}, $$ where $\...
2
votes
3answers
588 views

How can fiber optic image conduits consist of only fiber core, no cladding?

Looking at fiber optic image conduits, I found that they have a packing fraction (the ratio of the fiber core's area to the total area) of 100% (source here). In other words, they consist only of ...
1
vote
1answer
4k views

Visible light through a single-mode optical fiber?

If I understand things correctly, the optical fibers used for (long-range) data transmissions are generally single-mode fibers, transmitting light in the 1300-1500 nm spectrum. Now, could such a ...
1
vote
2answers
190 views

Minimum seperation between two Airy disks as a function of the distance between two point sources of coherent light passing through the same objective

I have two coherent point sources of light, $A$ and $B$, separated by a distance $L$, which I focus down to the diffraction limit using a high-powered objective (e.g. a $\approx 100x$ objective). If ...
3
votes
1answer
179 views

Is it possible to make an optical lense that is an analog to a gravitational lense?

There are many lenses that do all sorts of things. eg. horshoe lenses twist light, meta material lenses can boggle the mind. Is it possible to make an optical lense that is an analog to a ...
2
votes
2answers
220 views

Temperature-induced wavelength shift of optical coatings?

Optical coatings designed for reflection or anti-reflection are made of many thin layers which will expand when heated. What will the effect be on the wavelengths the coating will reflect when the ...
1
vote
1answer
597 views

Electrooptic Tensor, Relating Tensors to Orientations

So I'm trying to gain a better understanding of electrooptic tensors: An example of a quartz electrooptic tensor is given. I know in order to best implement this crystal, in order to get the highest ...
0
votes
1answer
96 views

Creating small polarised scientific lenses?

How would I go about creating small polarised scientific lenses? Thinking 5mm by 5mm, with a light-source behind it for the purposes of reducing (polarised) surface reflection (assisted with a cross-...
2
votes
1answer
596 views

Optical Waveguide's “Base Bandwidth”

Consider a dielectric slab waveguide (lossless, isotropic) illuminated transversally from the vacuum (with coherent, monochromatic light). We define the base bandwidth of a waveguide (or optical ...
0
votes
1answer
437 views

Depolarisation of Light in Optical Fibre

I have a question for which I can't seem to find a solid answer in literature and wondered if anyone could offer advice or reliable references please: How does light depolarise in non-polarisation-...
0
votes
2answers
7k views

What is optical confinement?

What is optical confinement? What is it intuitively? How does this 'optical confinement' affect the performance of a laser?
4
votes
2answers
1k views

Why are there direct bandgaps?

This Question has been bugging me for sometime. Some semiconductors have direct bandgaps and indirect bandgaps. So what causes a direct bandgap to occur? The physics behind ,why there are direct ...