Questions tagged [geometric-optics]

The subfield of optics in which light propagation is approximated in terms of rays. It mainly includes reflection and refraction on surfaces.

Filter by
Sorted by
Tagged with
-2 votes
1 answer
31 views

Derivation for the formula of number of images formed by two inclined mirrors [closed]

I just can't memorize the formula without its clear derivation!! It would really help if someone derived it clearly!! The i have listed the formula and they are correct too, but without its proof! Its ...
user avatar
0 votes
1 answer
32 views

How do objects across a flat surface appear distorted?

Imagine looking at an object after a planar interface. It can be proven that if angles are small, $y'=y\frac{n_1}{n_2}$. Steps are easy but this result confuses me and I'm not sure to have understood ...
user avatar
  • 193
0 votes
1 answer
25 views

Specular and diffuse reflection at the same time

if we know that tomatoes absorb all the light and reflect the red diffusely, how can we see the reflection of all the light specularly at the shinnig point? there isnt an absorption of other colors at ...
user avatar
0 votes
1 answer
32 views

Phase difference and path difference relation confusion

If two light waves of same wavelength reaches the point $ P$, then what is the relationship between path difference and phase difference? In many books I have seen that they assume two 1-D equation ...
user avatar
1 vote
1 answer
43 views

What is the minimum size of an object to cast a shadow on the entire Earth?

When I fly up(don't ask me how), I see how my Sun's shadow on Earth is getting bigger but dimmer as the Sun's light is reflected from other objects. As I flew higher and higher in the direction of the ...
user avatar
  • 1,889
1 vote
1 answer
33 views

General criteria for whether or not a mirror will form images

The most general form of a mirror in one dimension is a differentiable function $f:\mathbb R \rightarrow \mathbb R$, for which $f(x)$ determines the vertical position of the mirror at displacement $x$ ...
user avatar
  • 245
0 votes
0 answers
9 views

Change in temprature inferior needed for a mirage

I would like to calculate the change in temperature needed to get an inferior mirage effect. I want to derive $\frac{dT}{dz}$ and am given the Gladstone-Dale relation for the refractive index $n(z)-1=...
user avatar
1 vote
0 answers
26 views

Could you please suggest physics textbooks that discuss object velocity and image velocity pertaining to spherical and plane mirrors?

I have seen texts such as Zemansky's University Physics or Halliday Resnick's Physics (fundamentals and the older edition) etc. do not contain discussions on object velocity, image velocity (and their ...
-1 votes
0 answers
54 views

In geometric optics, why must a reflective surface be "smooth" rather than just $C^1$?

Smoothness of a surface tends to imply that a surface is $C^\infty$. However, all optics I encounter, it only seems strictly nessecary for a surface to be $C^1$.
user avatar
0 votes
7 answers
493 views

How we can distinguish objects separately, even if light rays from them are getting mixed up in space surrounding them?

I am a high school student and I am very confused in one thing in optics (ray optics) which I think is the most basic thing but didn't find any answer on internet, before I ask let me present one ...
user avatar
1 vote
1 answer
45 views

How to find the index of refraction of a glass cube with limited information?

This is a problem from my textbook that I've been struggling to solve: A ray of light from a laser pointer is incident on the "upper" surface of a glass cube at the angle of 70°. The ray ...
user avatar
  • 13
2 votes
1 answer
22 views

Difference between Myopic Eye and Normal Eye with ray diagrams

So I have a problem where i am getting confused what happens when an object is placed in front of a myopic eye. Also I have another problem ie. why the image becomes blurry if it is formed beyond the ...
user avatar
0 votes
1 answer
85 views

How to determine aberrated wave front at exit pupil of a lens system using ray tracing?

I am working on building a very simple optical simulator for my workflow. I am stuck at a point where I am trying to simulate the impact of diffraction on a lens system that has geometric aberrations. ...
user avatar
1 vote
2 answers
48 views

How does paint of two color mix to form one of new color?

Suppose I take bit from two paints of different color and I smudge both on the same spot on a piece of paper, I will get a new color. What exactly is the physics behind this?
user avatar
0 votes
0 answers
26 views

Can a tall chain of mountains rise, apparently like the Sun, if watched from a plane approaching the mountains?

Assuming you are in a passenger plane that flies at 11000 meters having a speed of 1000 km/h, and pointing to a chain of mountains 5000 m tall, is it possible to see the chain rising from below the ...
user avatar
1 vote
1 answer
82 views

How does viewing through two eyes give us a sense of depth?

With ONE ray, your eye can never determine where the object is. Note that in your diagram, the eye can deduce the line along which the apparent image is, but to make a point, we need two lines! Who ...
user avatar
1 vote
1 answer
40 views

Thin layer of air between lenses in contact

consider the following case for thin lenses Case 1: lens between two different medium applying refraction through curved surfaces two times and subtracting - $$\frac{\mu_{oil}}v - \frac{\mu_{air}}u = ...
user avatar
1 vote
1 answer
38 views

What is the plane of a concave or convex mirror?

What is the plane of a concave or convex mirror? Is it along its principal axis or its area? I am convinced that the plane should be along the area of mirror but i am not sure about it. I tried to ...
user avatar
  • 15
0 votes
0 answers
32 views

Maximum Intensity for Gaussian Beam

So I wanted to find out the maximum intensity for a Gaussian beam for a given aperture $D$ which is valid for near and far field, as a function of distance $z$, wavelength $\lambda$ and initial power $...
user avatar
0 votes
1 answer
34 views

Paradox of light passing through prism and glass slab

When white light passes through a glass slab, Newton's assumption is that a slab is made of 2 glass prisms placed in opposite direction, such that dispersion of both is cancelled out and a white light ...
user avatar
3 votes
2 answers
67 views

What exactly is "dense" in Optical Density?

My book states that: When passing from one medium to another, if light slows down, the second medium is said to be optically denser than the first medium, and if light speeds up, then the second ...
user avatar
0 votes
0 answers
27 views

Image Formation at a Spherical Refracting Surface

I was thinking about refraction at spherical refracting surfaces and what the required conditions be for the formation of a real or virtual image? I thought I could use this formula: \begin{equation*} ...
user avatar
0 votes
0 answers
30 views

Can we apply lens makers formula when medium on either side of the lens is different?

Lens maker's formula, which is $\frac{1}{f} = ({n_{liquid}{-1}}) [(\frac{1}{R}) - (\frac{-1}{R})]$. Can one apply lens makers formula when medium is different on both sides? If NO, why? Should we use ...
user avatar
1 vote
2 answers
88 views

How to understand the polarization rotator using a PBS, a quarter-wave plate, and a mirror?

In optics experiments, I often see the following optics configuration to rotate the polarization of an incident linearly-polarized laser beam. The final reflected beam has its polarization rotated by ...
user avatar
  • 13
0 votes
1 answer
25 views

What is the significance of back focal length in a lens?

I work with C-mount cameras a lot and I've noticed that the lens' manufacturers often list back focal length (BFL) among optical specifications. (That's the distance between the lens' last optical ...
user avatar
0 votes
3 answers
59 views

How does a rainbow show all of its colours?

My question is tied closely to this one, asked a while back on the website. As far as my understanding goes, a rainbow is formed by sunlight undergoing two refractions and a reflection inside ...
user avatar
1 vote
0 answers
70 views

Time taken to travel by light a minimum or maximum?

I'm stuck on the following. We know that the path taken by light to travel between 2 points A and B corresponds to the path which minimises time elapsed. However, from relativity we also know light ...
user avatar
  • 1,317
0 votes
1 answer
43 views

Finding Shift due to Refraction in Multiple Slabs when the object and viewer are in different medium [duplicate]

So, suppose we have three rectangular slabs each of varying refractive indices(R.I.) and thickness. We have a real point object to the left of the first slab and we have an observer to the right of ...
user avatar
0 votes
1 answer
36 views

Apparent Height as a Function of Distance

It's no secret that objects that are far away appear smaller than they actually are. Objects that are closer to us appear bigger than they are. Suppose I observe an object a few metres away from me. I ...
user avatar
0 votes
2 answers
43 views

Can we tell on which side of a lens an image appears?

Suppose I look through a single, thin, converging lens at an object on the opposite side. Depending on where the object is placed, the lens will either produce a real image on the side of the lens ...
user avatar
  • 6,259
0 votes
0 answers
7 views

Development of the incident light transfer matrix on a multilayer structure

I am trying to read an article whose objective is to simulate a DBR (Distributed Bragg Reflector), however I do not understand very well why the matrix that represents the change that light undergoes ...
user avatar
0 votes
0 answers
54 views

How can conservation of etendue be explained geometrically?

I have tried to understand the principle of conservation of etendue, more specifically the limit on concentration, but when I try to reproduce it with this simulator it doesn't seem to work. The angle ...
user avatar
0 votes
1 answer
43 views

Sign Convention in Ray Optics

While solving questions on Refraction due to 2 spherical surfaces the sign of the image formed after the first refraction (here at '$A$') depends whether the image formed is towards left or right side ...
user avatar
2 votes
1 answer
50 views

Geometric optics explanation of lateral (transverse) chromatic aberration

The majority of pictures explaining lateral(transverse) chromatic aberration look like this Here the focal point for red light is shifted closer to the optical axis and the focal point for blue light ...
user avatar
2 votes
3 answers
137 views

How does the combination of lens create a sharper image?

There's a line in a book which states that the combination of lens helps create a sharper image, but I don't understand how. Does more magnification mean sharper image?
user avatar
  • 21
0 votes
3 answers
74 views

Why image of vertical object is always a straight line and perpendicular to principal axis?

I am a high school student and I am very confused in geometrical optics, In all textbooks the mirror formula is derived by already assuming that the image of any vertical object (perpendicular to the ...
user avatar
0 votes
1 answer
60 views

Concave mirror and convex mirror placed facing each other [closed]

A convex mirror in a concave mirror each of focal length f are placed coaxially. They are separated by 4f and their reflecting surfaces face each other. A point object is kept on the principle axis at ...
user avatar
  • 15
2 votes
1 answer
71 views

Fourier Transform of a Wave Packet [closed]

In the analysis of coherence and interference, I encountered the following expression: $$F(t)=\Re\int_0^\infty\mathrm d\omega e^{-i\omega t}H(\omega)$$, where $\Re$ denotes the real part of the ...
user avatar
  • 91
0 votes
2 answers
45 views

What happens when light gets reflected and refracted at the same point?

Suppose that medium of refractive index n is placed on a mirror (as seen from the image), and the rest of the place is vacuum. A light ray is incident on the common point of vacuum, glass and mirror. ...
user avatar
0 votes
0 answers
25 views

Could a reflective beam expander deteriorate the lateral symmetry of a beam collimated from a single-mode optical fiber?

Background: I am currently concerned with getting a confocal time-correlated single-photon counting (TCSPC) setup ready for autocorrelation spectroscopy (fundamentally: fluorescence autocorrelation (...
user avatar
1 vote
1 answer
57 views

Using a transparent cup of water as a magnifier

When a transparent glass of water is placed in front of a striped background, it appears to produce this “magnified” view of the background in the center of the cup (i.e., the v shaped blue thing in ...
user avatar
  • 183
4 votes
2 answers
98 views

Rainbow reflections from salt crystals

Especially on a sunny day in the winter or spring, I often notice faint rainbows when I look down at the edge of the road by the curb. I am not sure what causes these rainbows, but I believe that ...
user avatar
0 votes
0 answers
26 views

Calculating lens size for head mounted display

I am trying to make a single-eye head mounted display in order to use with Drone - to see video from a drone with one eye and see drone with another one. I have a 2.9" display (size of image is ...
user avatar
  • 1
0 votes
1 answer
37 views

In a ray diagram for a camera the focal point is in between the lens and sensor, is this not wrong?

So I've read when the camera is correctly focused the focal length is the distance between the sensor and lens. But when drawing a ray diagram for the object, lens and sensor the the focal point ends ...
user avatar
0 votes
0 answers
16 views

Image formation by a concave mirror-

I have read that concave mirrors are converging mirrors so they form a real image . Real images are inverted and they are always obtained on screen. Then why we see the image formed by the concave ...
user avatar
  • 11
3 votes
0 answers
38 views

Prism deviation angle for small angles

Consider the following scheme for monochromatic light refracting through a prism, with the deviation angle $\delta$:                                               Let $\theta_1\ \wedge\ \alpha\ll1$ . ...
user avatar
1 vote
0 answers
31 views

Can I use all 4 sides of a polarizing beamsplitter cube as inputs?

The polarizing beamsplitter cube on the following diagram splits non-polarized light in the input a into 2 orthogonal polarizations: p-polarized light is transmitted into the output c while s-...
user avatar
  • 352
0 votes
1 answer
46 views

Proofs for off-axis focal lengths of a concave mirror

I am reading "Fundamentals of Optics" the 4th edition, by Francis Jenkins. The book mentions a conclusion for off-axis concave mirrors: That is, depending on: mirror radius of curvature $r$...
user avatar
  • 257
0 votes
0 answers
32 views

Physics behind the billet split lens method to form the interference pattern and how to accurately do it?

We know that Billet split lens is used to form interference pattern on a screen , my question is consider setup like of cut convex lens being placed symmetrically apart from each other by 2z distance ...
user avatar
0 votes
2 answers
44 views

How can I collimate a laser beam of 100 wavelengths in vacuum?

Before collimating, the beam will have diverged a bit to a radius of 5cm, the range of the wavelengths is 1400-1600nm and I don't want to lose more than 30% of initial power. I'm asking in general how ...
user avatar
  • 1

1
2 3 4 5
25