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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How to polarize a laser beam

I'm working on an optic project that I need my laser beam to be polarized. Do you a simple way to polarize my laser beam?
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23 views

Is there a limit to telescope resolution? [duplicate]

Could a strong enough telescope read a newspaper on a planet 1400 light years away, or is there a theoretical limit to the resolution of magnification?
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33 views

Why does normal incidence eliminate the photocarrier effect radiation in this experiment?

Here's a paper in which they use GaAs crystals at a few orientations to produce THz radiation, by means of Optical Rectification (OR). That's actually not what this question is about, though. They ...
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185 views

Is the human eye diffraction limited, or is there another limiting factor?

I know that most problems involving the human eye in my undergrad physics text book tell the student to treat the human eye as a diffraction limited system (ie to assume the only factor limiting human ...
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453 views

Are shadows cast on mirror surfaces?

While moving an object between a light source and a clean mirror surface, its shadow seems hardly visible (at least compared with a non reflecting surface). Is it correct that the shadow is not ...
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382 views

Inside a spherical mirror

imagine standing inside a sphere composed entirely of mirror surface; what does this look like? inside is lit by an invisible light source if each point encounters a reflection of itself, what is ...
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28 views

Imaging and the Electric Field

In this book (pg. 162), it mentioned that conventional lenses only focus propagating waves, thereby creating an imperfect image. In contrast, superlenses focus both propagating and evanescent waves, ...
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35 views

Intensity measurement of light

How can I understand which color my camera is more sensitive to? How do I calculate the intensity from a picture? My understanding: Calculate the value at one pixel and just integrate with total ...
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28 views

Single slit diffraction treated as a differential equation

I want to find the values of electromagnetic fields that result from single slit diffraction. This should be possible by solving maxwell's equations for appropriate boundary conditions. But I'm not ...
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57 views

Deviation on the Diffraction Pattern when not perpendicular

Due to Babinet principle, Diffraction pattern of an opaque .... ( you all know ). here my opaque is my wire. So, I know that if I change the angle between beam and wire ( I mean if I don't aim the ...
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61 views

Why under red light the additive synthesis of primary colors gives white where one primary color is absent?

Under White Light Under Red Light For instance, red & green under red light gives white.
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69 views

Interference of Beams with Different Polarizations

I have read in many places that orthogonally polarized light beams do not interfere. However, I also know that orthogonal vectors, such as force, do affect each other and give a resulting force. So, ...
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84 views

What is the electric field of a diffraction grating?

I'm trying to follow the equations in "Introduction to Modern Optics" by Fowles. He starts out with equation for a single slit of length $L$ and width $b$: $ U_p = C \int \int e^{ikr} dA $ where $U$ ...
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Determining the spatial imaging resolution based on a pinhole diffraction pattern

I aimed a 780 nm/1mW laser at a 1μm pinhole and took a picture of it using a lens and a CCD camera. The magnification of my imaging system is ~25 times. I wrote some code that takes the image of the ...
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60 views

Connection between Polarization and Coherence in optics

It is not completely clear to me how the notions of polarization and coherence, in optics, work together! I quite understand both of them but it's still hard to grasp their deep connection. I'm quite ...
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65 views

Different colors and Metamerism

Given the following graphs: They describe the response for two different colors . In addition that both colors are metamerism. My question is why? how can I prove it? Thanks
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63 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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60 views

Is surface brightness constant as a function of distance?

Well of course it is - the flux drops off as the square of the distance, but the solid angle subtended by the source drops off the same way, so surface brightness is constant, right? Yet other ...
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199 views

what happens inside linear polarizer sheet (at microscopic level) when unpolarized light falls on it?

(1) What happens at microscopic level when unpolarized light falls on a linear polarizer sheet ? i.e. Due to what thing inside polarizer sheet, only those EM waves are passed whose plane of vibration ...
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87 views

Can QED explain this or do I have revert to the classical model of light?

I want to know can QED can explain this image,like why there are someplaces with low light (shadows) like behind the chair, and why there are some places that are bright(rest of the floor). I know ...
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Why doesn't the sun reflect off Earth's oceans from space like a billiard ball?

According to Phil Plait, Earth is proportionally smoother than a billiard ball (http://blogs.discovermagazine.com/badastronomy/2008/09/08/ten-things-you-dont-know-about-the-earth). The water surface ...
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70 views

Diffraction Pattern when not perpendicular

In single slit diffraction, we always assume that our waves are perpendicularly aimed towards the slit. But what if we aimed our waves with different angles ( for example 60 deg)? If we send the ...
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32 views

What is the Refractive Index of a colored wire?

I'm working on a project that I want to compare the amount of reflection of a copper wire when is uncoated and when it's colored with watercolor. and I want to predict the amount of reflection with ...
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157 views

Diffraction pattern without a slit

A few weeks ago, I aimed a laser at a wire perpendicular and interestingly, I saw the diffraction pattern, like the picture below: Why is this happening? I mean, I don't have any slits and I'm ...
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28 views

type of polarization required to generate surface plasmon resonance

The generation of surface plasmon depends on the polarization state of the impinging light beam. If the polarization of the beam impinging a nanosphere is along the z axis then the dipole radiation ...
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How to measure the Intensity of light?

I'm working on a project and I need to measure the Intensity of light( that is appeared on a screen ) in some different places of it to compare them ( in order to compare the amount of reflection ) I ...
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Using reflective optics concepts to focus gas pressure in a vacuum

At very low vacuum pressures the bulk behaviour of molecules can be approximated by non interacting particles bouncing off of the chamber walls: For an monotonic molecule such as He with perfect ...
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219 views

Size of object from its image [duplicate]

If the quality of the camera (i.e. the megapixels) (assume to be $x$) of the camera is known and an object is kept a known distance from the camera (assume to be $d$), can the actual width and length ...
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202 views

What is the visible spectrum to common mobile phone cameras? [closed]

With my iPhone I can see the IR emitter on a tv remote, which could be around 940nm, but I thought cameras generally tried to filter for the human visible spectrum (i.e. sub 700nm). I'm trying an ...
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395 views

Huygen's principle and why can't we see atoms with light

First of all, I'd like to discuss Huygen's principle. In order to explain waves diffraction, it says that every point in a wave front behaves as a source, so the next wave front is the sum of all ...
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3answers
438 views

Do we have a deeper understanding of Fermat's Principle?

Fermat's principle says that light travels between two points along the path that requires least time as compared to other nearby paths. But why this is so? Why can't light follow other paths? How ...
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39 views

Poisson Spot vs. Shadows

In textbooks, whenever I read about the Poisson spot, it involves a disk, and having light waves diffract around it and interfere constructively in the center. At the same time, when I read about ...
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70 views

Question about reflecting telescope

In a reflecting telescopes, light is reflected from a primary concave mirror to a secondary mirror. But the secondary mirror is never placed at the focal point of the primary mirror. Why is that? ...
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84 views

Electromagnetic transfer function

In a paper on the superlens, I came across the term of "transfer function". I understand that the transfer function relates the output to a given input, but I've been unable to find a formula for the ...
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47 views

Does Silver posses a color or Is it colorless reflection? [duplicate]

Why is silver said to have a color whereas water is not? Water is colorless because is allows penetration of light and doesn't reflect a colored wavelength, whereas Silver reflects light from its ...
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Problem on Malus law? doesnt work on certain angles [closed]

if Unpolarized Light falls on two polarizing sheets placed one on top of other. what must be the angle between the characteristics directions of the sheet a) if the intensity of the transmitted ...
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33 views

Get actual object size in mm using camera [closed]

How to get actual object size in mm when we know Object distance, focal length, image width in pixels and camera angle,
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37 views

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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32 views

curvature tensor

I'm reading Tailored freeform optical surfaces, and having trouble in understanding it. Setting: A ray from a source $\mathbf{s}$ aimed at a point $\mathbf{p}$ on the optical surface, the ...
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35 views

Why we see a distant object more closer from us with a telescope?

The side magnification in the image obtained by a telescope its always less than 1, then, Why we see a distant object more closer from us?
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56 views

Is a non reflective display possible?

Can you think of a surface, that emits light, but doesn't reflect any light coming from outside (absorbs it)? Under what circumstances would this work?
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76 views

In a lens the image formed by the first surface serves as the object for the second surface.What is the reason?

When deriving the lens maker's equation I faced the problem of understanding the logic behind this reasoning "image formed by the first surface of a lens serves as the object for the second surface."
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60 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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Optimal wavelength for low IR attenuation under normal atmospheric conditions?

I can't find any good data about the transmit attenuation of infrared light in the atmosphere transmitted horizontally (there is a bunch of stuff detailing penetration of radiation from space, but ...
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28 views

How much UV light do we have on the ground? [closed]

We cannot see it. But suppose each UV photon is replaced by a red light photon, does it make the world look as bright as it is just before the sunrise?
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371 views

Why do we use the index of refraction for yellow light?

When we do problems with optics and refraction, we’re usually given a set of indices of refraction to work with; for example, the index of refraction in air is about 1.00, the index of refraction in ...
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164 views

Re-reflecting in HUD optics

Simple HUD optics design can be described with below image. (source : http://www.mikesflightdeck.com/hud/head_up_displays.html) As you can see, if combiner and colimating lens(after fold mirror) ...
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91 views

Do parallel rays reflecting at a mirror not intersect at one point? [closed]

Let's take a concave mirror with $CP$ as its principal axis. Let's assume that a parallel ray $p$ to $CP$ reflects at $A$ to pass through the focal point $F$. Then, $\angle CAF=\angle ACF$, which ...
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1answer
813 views

Brightness of light sources

I would like to know what determines the brightness of light. I'm confused, After hours of reading, I got these definitions mixed up I need to link them together: Light intensity Brightness of ...
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120 views

Green light on red article

When white light falls on an object the body absorbs all colors of light and reflects some colors of light which we see the object to be.For eg.A red ball reflects red color and absorbs the rest ...