Tagged Questions

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.

3answers
374 views

Why does shining a laser into an iPhone camera create these shapes?

When I shine a laser light into an iPhone 6 camera I get these weird shapes: The shapes are in no way in the background behind the laser. What causes these to appear? I know about typical lense ...
1answer
163 views

Interference of LED Lights

I have read that colored LED lights are nearly monochromatic. Does this mean that they could be used in double slit interference?
2answers
6k views

Why are gold mirrors yellow?

Why are golden mirrors yellow? Do they add a yellow component to the spectrum or absorb non-yellow components? If they absorb, then why are they used in telescopes being imperfect? If they add a ...
2answers
260 views

Is it possible to calculate the dimensions of ANY object in a picture having at some known distance an object on know dimensions?

Is it possible to calculate the dimensions of ANY object in a picture having at some known distance an object on know dimensions? I'm thinking about the scenario where someone is holding a smartphone ...
0answers
27 views

Converging rail tracks

When we look at parallel rail tracks, it appears to converge at a certain angle. Let us say the width of the tracks is d and the height of the eye is h. Assuming one stands in the middle of the tracks,...
0answers
29 views

Lens-Mirror systems and conservation of specific intensity

This came out of a discussion I started yesterday and a related discussion I found. I'll recap the problem quickly: Consider two blackbodies, with surface areas $A_1$ and $A_2$ and temperatures $T_1$ ...
0answers
34 views

Thickness of glass sheet with Michelson's interferometer

I've got a question, are we able to calculate the thickness of a glass sheet by using Michelson interferometer experiment ?
1answer
898 views

Way of measuring thickness of a glass [closed]

Imagine you have a laser pointer and a glass. You don't know the refractive index of the glass and you just have Wavelength of laser! How can you measure the thickness of glass? (I have some idea but ...
2answers
129 views

Appartus for Young's double slit?

I am wanting a full description of an apparatus used for Young's double slit (not necessarily the one that Young himself used though), which takes monochromatic light (though not laser light) and ...
2answers
118 views

Video of light passing through water

How is this possible? https://www.youtube.com/watch?v=EtsXgODHMWk Video shows beam of light travelling through water. I was under impression that Einstein's equations showed that light speed is ...
1answer
240 views

Why does circularly polarized light break time-reversal symmetry?

I've encountered some interesting paper on 2D materials where authors use circularly polarized light to break time-reversal symmetry to split energy levels. Here you can find the paper: Valley-...
0answers
16 views

What is micropulsing in optics?

I've seen this in a presentation, but I am not quite sure what it means. Is it simply emitting light in a sequence of very short pulses?
2answers
166 views

What is really a light ray? [duplicate]

I've been studying geometric optics and I'm still a little confused with this idea of light ray. In the book I'm studying everything is being done starting from Fermat's principle which states that ...
5answers
5k views

If a lens focuses all incoming light to a point, how do we get 2D images?

How do lenses produce 2-dimensional images, if a lens bends all incoming rays of light to intersect at the focal point? Shouldn't this produce a single dot of light on a screen placed at the focal ...
3answers
3k views

Calculating light's lateral shift in a glass slab

I have tried to compute light's lateral shift after passing through a glass slab In terms of the incidence angle $\theta_1$, the slab thickness $d$ and the refraction index $n$, I have found that ...
2answers
103 views

1answer
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 (...
0answers
175 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 ...