Optics is the study of light, and its interaction with matter. It includes topics such as imaging systems, fiber optics, lasers, quantum optics, and more.

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Could you use polarization filters to make a privacy screen?

I remember seeing that brusspup video where the polarization filter on the monitor was removed and put it in his glasses, causing only the wearer to see the screen. (, and) I was thinking, would ...
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57 views

How does one calculate how big something has to be, to be seen at a given distance? [closed]

Ignoring curvature of the Earth. How do I calculate the size an object would need to be in order to appear to be approx 1cm tall at a given distance?
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30 views

Focus correcting screen [closed]

With the rapid approach of VR, and being someone who's always needed glasses! I have been curious about this for a while. Is it possible to correct the focus of a lens by adjusting the image on a ...
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33 views

How does magnification work in lensless optical setups?

In my optics classes, I have only ever seen magnification defined in conjunction with the thin lens equation. However, in a lensless optical setup such as lensfree in-line holography, how does one ...
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97 views

Converting Stokes Parameters to Jones Vector

How do you convert a Stokes vector into a Jones vector? I am only concerned about fully polarised light, and I need to convert the Stokes parameters (or the azimuth and ellipticity angles) as measured ...
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83 views

How come lenses alter the path of photons?

From what I know, photons are theorized particles and believed to be massless (just energy) and travel at the speed of light. How come a lens, which is an object made of atoms, can bend a light path? ...
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43 views

Does light influence transparency?

Let's consider this thought experiment: There is a sheet of a (more or less) transparent material. On one side of the sheet there are two light sources illuminating one spot on the sheet. The sources ...
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22 views

Diffraction pattern in the image plane?

Consider the setup below: In all cases the relationship between $u_o(x_o)$ and $u_f(x_f)$ is given by a Fourier transform. My question is, when is the same true for the relationship between $u_f(x_f)...
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57 views

Why does narrower slit give a wider diffraction pattern in single slit diffraction?

I was reading on this website and it said that one of the characteristic of single slit is narrower slit give a wider diffraction pattern but why? http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/...
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43 views

Can a biconcave thick lens ever have a positive focus? I.e. if both sides have radius of curvature -/+R?

Since a thin biconcave lens has a negative focus, can a thick biconcave lens with a certain thickness have a positive focus if both sides have the same (magnitude) radius of curvature?
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50 views

How can I change the divergence angle of a single mode fiber

For my project I use the end of a single mode fiber as a "transmitter". I need to set the divergence to 20 micro radians. Is there an equation how to calculate the divergence and the necessary optics ...
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56 views

Why rainbows form around flashes?

I read that to see a rainbow, your back must be towards the sun, and you have to look at roughly 42 Degrees from the imaginary line to spot the red band. But many times, me and many of my friends see ...
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70 views

Why does Diffracted Light cone diameter change in relation to angle of light beam?

I have a question about light diffraction. Take a look at these images of the Pantheon oculus. Now what I don't understand, in the first picture, the light is coming in from overhead and forms a ...
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39 views

How do we call in English scientific terms the Fermat's principle about back and forth light traversal?

We know that the path followed by the light from point A to point B is independent of the direction of propagation of light. This is what is called in French "le principe de retour inverse de la ...
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84 views

When is a negative focal length used in optics?

I'm getting confused with conventions. I was wondering if this logic is correct: If an image appears on the same side of an object, then we use a negative focal length for determining information ...
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47 views

Michelson interferometer

I'm reading about an experiment done with this piece of equipment. The aim is to measure the thickness of a piece of plastic. They use white light, so the central fringe in the interference pattern, ...
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90 views

Speed and multiple images

Why an object (or something else) create multiple images of itself when it is moving fast? An earphone spinning in circle for example.
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50 views

What are the right signs? [closed]

This is a question provided in my book: An object of height $2\ \mathrm{cm}$ is placed at a distance of $2.5f$ from a concave mirror where $f$ is the focal length. Find the height of the image. ...
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45 views

pinhole in projector screen

Consider a conventional slide projector projecting a properly focussed static image from a photographic slide onto a conventional screen, with a second screen placed a short distance behind that one. ...
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54 views

What is the physical interpretation of Power Spectral Density (PSD) in optical tweezer?

For the calibration of an optical tweezer, the PSD of position values are plotted. If it follows a certain behavior having two regions - free diffusion and potential limited regions, then the trap is ...
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59 views

Optics Diffraction Grating Plot

I was unsure whether to post this in physics stackexchange or mathematica stackexchange, so I posted it in both. I'm trying make an intensity plot for a diffraction grating that contains 100 lines/mm....
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68 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? ...
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59 views

Are there Non-conformal maps encountered in Physics?

We always encounter Conformal maps in Physics, may be they are easier to study, but are there Non-Conformal transformations encountered in Physics anywhere? if they are encountered, where are they ...
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192 views

How to interpret the complex index of refraction?

The index of refraction which represents how much light gets refracted when entering a medium is defined as $$n = \frac{c}{v}$$ I have seen it stated in several places, such as here, that we can ...
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37 views

What sizes are detectable from 1m using a fairly good cmos camera?

I haven't ordered a CMOS camera module yet, but I am planning to use it to detect a small object from ~1-1.5 meters. Just too be specific, say I am using the following CMOS camera (although if you ...
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31 views

Interpretation of different values of antibunching

When the frequency resolved second order correlation function at zero time delay, $$g^{(2)}(\omega_1, \omega_2) = \frac{\langle a_1^\dagger a_1(t) a_2^\dagger a_2(t)\rangle}{\langle a_1^\dagger a_1(t)\...
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61 views

Can we trap living cells in optical tweezers?

I read that optical tweezers work on the principle of radiation pressure caused due to momentum change of incident light due to refraction from a spherical object. For refraction to happen the object ...
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123 views

Collimated light directly into a multi-mode fiber

This is my question - Will a collimated, incoherent light, consists of a limited angle, that "hits" a multi-mode fiber facet exit the fiber as collimated? (just to be clear, no lens is involved. I ...
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127 views

Smallest object resolvable by optical microscopy

I am wondering what is the smallest object you can resolve with an optical microscope. I am aware of the equation $\delta=\frac{\lambda}{2\textrm{NA}}$ that basically gives you the resolution. $\...
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1answer
84 views

How can the active area of a photodiode increased?

I use photo-diode VTB8440BH. To increase its active area I was thinking to put a lens in front the diode would enlarge its active area. What kind of lens would be beneficial one? I was thinking of a ...
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121 views

Doppler shift from a transversely moving plane mirror

Below is the diagram of the question I have on the Doppler shift of a light emitted from a stationary light source $S$ at an angle $\theta_1$ toward a transversely moving plane mirror $O$ having ...
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142 views

x-ray diffraction of crystals

In explaining x-ray diffraction of crystals, usually the approach is to consider the atoms absorb radiation and scatter it, at some angles constructive interference occur and bright spots can be ...
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103 views

The Thomson scattering optical depth for a photon ar radius r

I am looking to understand some more about the physics of gamma ray bursts. In particular I am looking at the origin of the "prompt emission". Some of the energy associated with this prompt emission ...
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68 views

Transmission of light, sub-wavelength apertures, and cut-off frequencies

I was hoping someone could please explain how the transmission of light through a sub-wavelength aperture in a metal film, at a particular wavelength, changes when the aperture is: i) above cut-off ...
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216 views

is copper a non-magnetic?

I'm working on an optics project that I'm using Fresnel Equation for Intensity. but I've got a question, is copper a non-magnetic ? You know because in Fresnel Equation, for non-magnetic materials ...
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38 views

Recreating an image from a photometer or similar light-detecting device?

I'm thinking if it is possible to recreate an image from data from this kind of device. It is known analog signals theoretically have infinite resolution, but since we use them in discrete systems (...
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64 views

Image formation or Diffraction?

I was watching this video on the YouTube channel Veritasium. In this episode, the host shows people paper containing holes of different shapes in the middle. So there is a paper which has a hole in ...
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329 views

How can we see objects that are so far away? [duplicate]

The HUDF used to be the deepest image of the universe ever taken by the Hubble telescope, the furthest star in this image is 59000 light years away. The star in question: Now Imagine a light ...
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66 views

Power of several focused laser beams on a small surface

After viewing this: My Homemade 40W Laser Shotgun Will the initial 40W power of the diodes beams be roughly transferred to the targeted surface where the 8 beams are focused, or will there be a power ...
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68 views

Patterns in a spinning wheel [duplicate]

Why do we see patterns on a rotating wheel with spokes which seem to rotate counterclockwise or clockwise as and when the wheel accelerates or deaccelarates. What I mean is the patterns like this
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166 views

Reflectivity of Metals - real and imaginary part of k-vector and complex dielectric function

De electric field component of an electromagnetic wave that is traveling in the $x$-direction is given as $$E(x,t) = E_0 e^{i(kx - \omega t)} $$ with $E_0$ the amplitude and $k$ the wave vector. From ...
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27 views

difference between plasmonic wave plates and usual wave plates

plasmonic waveplates are constructed using the generation of surface plasmons. Is there any difference between these plasmonic wave plates and the usual wave plates used in optics, besides the ...
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52 views

Polarization and Reflection [duplicate]

The polarization is a property of waves that can oscillate with more than one orientation. Given this, when the light is reflected from a surface, does the reflection change the property/orientation ...
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1answer
52 views

Plane Mirror as the Screen in Young's experient

If I place a plane mirror instead of the screen in the Young's double slit experiment, what will I see? Will the bands appear on the mirror face?
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80 views

Position dependent refractive index [duplicate]

How to determine the angle of refraction when the medium has position dependent refraction index? Lets say that the angle of incidence on the glassy slab is $\theta_1$ and the ray goes through the ...
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1answer
70 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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44 views

Could satellites achieve orbit using current laser technology

My question is, could we, using current laser technology sufficiently scaled up, launch a lightweight, say a GPS navigation satellite, into earth orbit? The main objection to me is maintaining the ...
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1answer
39 views

Florescents and radio waves

Okay so if you put a florescent light bulb in front of a certain radio, the radio waves excite the mercury inside a causes them to emit UV light which makes the outer coating of the light bulb light ...
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105 views

Could laser speckle patterns be used in diagnosing vision defects?

At the London Science Museum some years back, I saw a device which projected a laser speckle pattern and had a sign explaining that it would appear stationary for people whose eyes were correctly ...
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87 views

Significance of colours in photoelasticity

I already checked similar question at Physics SE, but none gives me a clear answer, also it is a bit difficult for me to understand it from wikipedia as I couldn't find relating material to my ...