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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Does “converge” mean intersecting and producing image when we are taking about convex lenses?

After reading the chapter on convex lens, I saw several places where "converge" is used. In the very beginning of the chapter, my book says "converging lenses bring light together". So I thought ...
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47 views

What is the frequency of the color black?

Our eyes don't see light; they detect vibrations in the 400-800 THz range that we call color. Since our eyes can detect the color we call black, what is its frequency?
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What is the wavelength of the light and how far away from the central maximum are the first and second maxima? [on hold]

A single, monochromatic light source is shined through an etched, flat prism with a slit separation of 0.025mm. The resulting interference pattern is viewed on a screen 1.25m away. The third maximum ...
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What is the small angle measurement from the central maximum to the first maximum? [on hold]

Two thin slits with separation of 0.0200mm are placed over monochromatic red laser of wavelength 632nm. What is the small angle measurement from the central maximum (zero degrees, in-line with source) ...
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30 views

What is the total internal reflection?

From what I read, it sounds like when a light ray passes from one medium to the other, if the critical angle is reached so that the refractive ray is at 90 degree with the normal, the light ray does ...
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517 views

Why does an image form at the intersection of light rays?

If image is simply what we see, then why, when light rays bend in the atmosphere, enabling us to see the sun, is there no intersection of rays? The concept is strange. I can not relate it to ...
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12 views

How are aberration levels measured?

I was reading reading the paper: Predicting subjective judgment of best focus with objective image quality metrics when I come across this statement: Through-focus visual acuity (VA) was ...
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10 views

When to use lateral magnification vs angular magnification?

What is the essential difference between lateral and angular magnification (like why do we need to use both and when do we use which)? Also, is there a relationship between the two magnifications?
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42 views

Why is the index of refraction different for different wavelengths? [duplicate]

The index of refraction can be written as $$n=\frac{\lambda_v}{\lambda_m}$$ where $\lambda_v$ is the wavelength in a vacuum and $\lambda_m$ is the wavelength in the medium. I’ve been told that since ...
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1answer
22 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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59 views

General proof of formulas of geometric optics?

In most lf textbooks formulas of geometric optics like lens maker formula and base formula for that are proven (or rather verified from my point of view) by taking specific case (ray diagram) and ...
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28 views

Visible wavelengths of air fluorescence data - needed for school demo laser telephone design

I'm seeking information about fluorescence in visible wavelengths (390-700nm) of any of the main constituents of air ( $ N_2, O_2, CO_2, H_2O, CO, etc. $) that can be excited with a (hopefully ...
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51 views

Red light in the depths of the ocean

I've read that fish in the deep ocean tend to be red because it makes them look black for other fish, thus reducing their chance of being eaten. Why do they look black?
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46 views

Optics phenomenon with my glasses?

When I look through my glasses toward the extreme left, a very odd and intriguing phenomenon occurs: The border of everything I see is lined with a hazy blue lining on the left and a hazy yellow ...
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16 views

Can I use an optical long-pass filter as a short-pass filter if I just collect the reflected light?

The transmission spectrum filter of long-pass filters are often better shaped than short-pass filters because long-pass filters are often specified for use in a very broad region from 200nm to 2200nm. ...
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15 views

White light polarization by ground\sky

Why does light from the sun gets a slight (horizontal) polarization after bouncing from the ground? And same question for light which is scattered from the sky. Thanks.
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166 views

Why are mediums always represented as straight and parallel lines in Ray optics?

I have been reading Ray Optics lately and I always see that the interface between mediums are always represented as Straight lines in ray diagrams. There is no mention that they are considering an ...
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1answer
23 views

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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21 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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1answer
23 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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31 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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1answer
45 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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1answer
54 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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17 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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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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19 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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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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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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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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37 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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1answer
26 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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1answer
39 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? Update: How can I draw ...
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1answer
31 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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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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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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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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21 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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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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1answer
63 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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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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28 views

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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1answer
39 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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1answer
35 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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2answers
58 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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2answers
73 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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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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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? ...