2
votes
1answer
56 views

A beam of light, traveling around a planet

Some time ago, I happened to have found one problem: The refractive index of the planet's atmosphere decreases with height above the surface under the following law: $$n=n_0-\alpha h$$ ...
2
votes
2answers
43 views

does the positon of the virtual image change when I change position?

I placed a box in front of a plane mirror I looked at the image and smudged a bit of Vaseline on the mirror as a mark to indicate where I thought where the virtual image was. After that, I ...
2
votes
1answer
39 views

Optical signal filters

Are there any optical filters which filter the signal's frequency and not based on the wavelength of the light? So what I mean is, if I have a modulated/pulsating light signal riding on a large DC ...
0
votes
0answers
35 views

What is a good textbook to learn how to ray trace light through an optics system in 3d?

I can do 2d problems easily, but I need to learn more to do a 3D ray trace. Can you guys point me towards a textbook? I'm having trouble dealing with the normal and incident rays in 3D
0
votes
1answer
32 views

Highly diminished image of an Object placed at Infinity

Consider an object at infinity. The rays coming from it are parallel to each other. Let one of the parallel rays pass through the focus $F_1$ of a thin lens, and let a second ray pass through the ...
0
votes
0answers
14 views

Obtain scale factor by coordinates from the camera projections

I have a following optical system: 3 cams (left and top, which is orthogonal to the left, and right, which is parallel to the left and orthogonal to the top) and the 2 cubes in the 3D-space with ...
0
votes
1answer
8 views

How to create crystalographic orientation map from indexed Kikuchi bands?

Can somebody explain a detailed procedure, of producing orientation maps? I need to implement this into a software. Right now im able to transform EBSD pattern to probabilistic Hough space, get lines ...
0
votes
1answer
24 views

Is there a way to calculate how a point source would be imaged in a system with spherical aberration?

I want to create a picture like this for the system I am building. (Source: WP page on spherical aberration) Can someone point me towards a book were I can learn to calculate this pattern on an ...
2
votes
1answer
40 views

Determinant of ray transfer matrix

Quick question on the wikipedia entry for the ray transfer matrix, which is defined : where $x$ is the distance of a point from the optical axis and $\theta$ the angle that the beam profile at that ...
5
votes
3answers
409 views

Will a prism widen a monochromatic beam?

The representation of the experiment which demonstrates that white light consists of many colors, invariably shows that the beam of white light is broadened inside the prism and is some what more ...
0
votes
1answer
50 views

Phase and amplitude information of an image

By applying Fourier Transform to an image we can get its magnitude as well as phase spectrum. A magnitude spectrum describes how various frequencies are attenuated and accentuated in that image but ...
0
votes
2answers
55 views

Image formation at surface of water

Consider a lake full of water which has an object immersed in it. Now, if an observer was at the surface at a sufficient distance so that the light ray from the object is internally reflected, should ...
5
votes
3answers
839 views

reflection at intersection of 2 mirrors

Consider 2 mirrors which intersect at an angle. If we draw a light ray intersecting the mirrors at their point of intersection, how will it reflect? What will be the normal at that point?
4
votes
0answers
60 views

Blonde hair looking green at certain angle

I have a friend who has blonde hair. And when look at an oblique angle, there's a tinge of light green in her hair. I've heard that the copper ion in pool water can make blonde hair green, but her ...
1
vote
0answers
38 views

Beamsplitter and Dielectric Mirror

Among two optical components. One is a Nd:YAG Laser 50/50 Beamsplitter and the second one is a Dielectric Mirror see pictures. Both of them almost looks like the same. If the specification is not ...
3
votes
2answers
66 views

Plano-convex lenses

When the spherical side of a planoconvex lens is towards the source we will see reduced aberrations normally we use it for the beam collimation. When we use two planoconvex lenses configuration why we ...
4
votes
1answer
134 views

Reconciling total internal reflection and the evanescent Wave

I understand that light is guided in a dielectric waveguide via total internal reflection. My question is regarding the origin of power contained in the evanescent field traveling along the direction ...
0
votes
0answers
76 views

Difference between the increase in optical path due to refraction and that due to reflection

If we place two glass plates of refractive index n and each having thickness t,on the way of a light ray the increase in optical path becomes (S2P-S1P)=2(n-1)t due to refraction through them,and the ...
1
vote
1answer
226 views

Why do we need screen to see real images?

As we know that concave mirror forms a real image when object is placed beyond focal plane. This image can only be seen if a screen is kept at the point of intersection of rays(sharp image).If any ...
2
votes
2answers
81 views

Calculating the rainbow angle

I've read that the angle for viewing a Primary Rainbow is between 40-42 degrees. How would I go about showing this? How would I calculate that angle from scratch? I figured that Snell's Law and the ...
1
vote
1answer
104 views

Numerical aperture of a lens

Using a laser setup, I was asked to determine the aperture of a given lens and then use some geometrical arguments and compare the theoretical value from the manufacturer and the experimental value. ...
4
votes
0answers
41 views

How does a microscopes optics expose defects in the users vision?

I've got cataracts in both eyes. My vision is correctable to 20/30, so the cataracts are essentially a non-issue in daily living. But when I use a microscope, which I do daily, (binocular, zoom ...
0
votes
1answer
109 views

Magnification in compound microscope

I was studying about compound microscope here I don't see why we multiply linear magnification of objective with angular magnification of eyepiece. Shouldn't it be both angular or both linear? Can ...
3
votes
2answers
621 views

Fermat's principle to prove the law of reflection

Fermat's principle tells that a light ray will follow a path from point $A$ to point $B$ so that the optical path length of this path is an extremum over neighboring paths. I wanted to use this ...
-1
votes
1answer
61 views

Determining a person's sight from his speech [closed]

Suppose we meet a person wearing glasses.Can we determine whether the person is short-sighted or long-sighted? However,due to courtesy,we are not allowed to ask him to try the glasses and in general ...
2
votes
2answers
104 views

Basic geometric optics question - how come we don't have to have exact focus to capture objects clearly?

The top frame of the image below shows an image formed on the screen (at right) of an object (pencil on the left) located at some distance $D$ from the lens. The lens focuses all the light rays ...
1
vote
3answers
182 views

Is there any optical component that uniformizes the incoming light?

Is there any optical component in existence that uniformizes randomly pointing rays?
3
votes
2answers
107 views

Is it possible to focus the sun in such way?

Imagine the sliding part of the mirror is controlled by computer and opens on intervals. Is it possible to increase the power of the beam by making it bounce between the mirrors thus going through ...
2
votes
2answers
104 views

Why would the reflection of a lamp by a bowl look like a heart?

I have this bowl roughly the shape of a circular truncated cone, and the lamp shines on the bowl at an angle. The reflected lamp light hit the bottom of the bowl and created a light ring that looks ...
2
votes
2answers
518 views

Fresnel distance and Geometrical limit

I read about the geometrical limit of wave theory. The source from where I read had a slightly different explanation to provide than here(The more rigorous answer is too complicated for me to ...
1
vote
1answer
42 views

Is it possible to build an optical system that increases the perceived surface brightness?

So is it possbile to build a system from lenses and mirrors that can make faint gas nebulas brighter or can be used as nightvision? If you increase the size of the aperture of a telescope it will ...
0
votes
1answer
146 views

Image formed in a compound light microscope

I am trying to understand whether the image formed in a compound light microscope is at infinity or not. I get conflicting answers everywhere I look.
3
votes
1answer
67 views

Why is there no dark band below a rainbow?

I've read articles about Descartes' theory of the rainbow and I can understand why there is a dark band of about 8 degrees (Alexander's band) between the primary and secondary bows: for all the water ...
1
vote
1answer
377 views

how does the mirror equation works and what lead to using of sign convention?

EVERYTHING HERE IS FOR CONCAVE MIRROR Everywhere I see the derivation of the mirror equation is given by placing an object before the focus and then proving similarity of the triangles to get to the ...
-1
votes
2answers
173 views

How many mirrors placed perpendicular to each other shall make a light ray completely reverse its path?

The answer is 3. But according to me 2 shall also work in 2 Dimensions? Does anyone has a theoretical proof?
2
votes
2answers
193 views

How to determine if a optical system is afocal?

I have to come up with a method to measure the focal length of a concave lens that's not in my lab guidebook. So I decide that I will build an afocal system with a convex lens and a concave lens and ...
0
votes
1answer
157 views

Infinite Mirror Face to Face With Infinite Two Way Mirror

If you are in deep space, and there is an infinite plane mirror, and in front of it there is another infinite mirror that is two way, with the see through side towards you, what do you see? Is it the ...
1
vote
2answers
156 views

Refraction of light in medium

Given that the plane $y=0$ separates the vacuum ($y>0$) from the optical medium ($y<0$), I would like to calculate the trajectory of a light ray starting at the point $(x_1,y_1)$ and ending in ...
2
votes
1answer
190 views

Optical Waveguide's “Base Bandwidth”

Consider a dielectric slab waveguide (lossless, isotropic) illuminated transversally from the vacuum (with coherent, monochromatic light). We define the base bandwidth of a waveguide (or optical ...
1
vote
1answer
120 views

How is Fermat's least time principle proven?

How is Fermat's least time principle proven? Or it is what usually is observed and is basis for the theories?
2
votes
1answer
1k views

Analytic solution for angle of minimum deviation?

Consider a simple prism with a prism angle $A$, angle of incidence $\theta_1$, angle of emergence $\theta_4$ and the first and second angle of refraction as $\theta_2,\theta_3$. the refractive index ...
1
vote
2answers
127 views

Good explanation of a real image?

Okay well I've started to study phys chem in school recently and I honestly can't get my head around what a real image actually is I've asked my teacher to demonstrated it but she's quite lazy, and ...
1
vote
2answers
206 views

Calculate the polarization vector on reflection or refraction from a dielectric interface

I am interested in ray-tracing polarized photons. I have code that works very well for unpolarized light. When a ray hits a dielectric interface the photon is either reflected or refracted by ...
2
votes
2answers
155 views

Change of hue near shadows

My brother is an artist and he told me his paintings look more natural when he slightly change the hue (color) of the surface near the transition between shadow and light. Here's three examples: (1) ...
2
votes
2answers
722 views

Why do powers of lenses get added?

In our physics class, we were told that a power of a lens is defined as the reciprocal of its focal length. Also, the powers of multiple lenses get added up. But I didn't understand why this is. I ...
1
vote
1answer
204 views

How mirror equation can explain farsightedness correction?

I have a friend who has just show me his medical prescription for hyperopia (farsightedness) correction and he needs glasses with 4,25 diopters for that, which seemed to be weird for me because I had ...
4
votes
2answers
291 views

Converting indices of refraction

If I know that the index of refraction of a given substance is 1.4 for the average wavelength (say 550 nm), and I would like to know what is the index of refraction with a wavelength of 832 nm, how ...
2
votes
2answers
270 views

Finding the illuminance from a triangular light source

Since most light sources in games are point-like, it's pretty difficult to approximate area light sources with point sources. As triangles are a universal form to represent 3D models (thus area light ...
0
votes
1answer
148 views

Formation on image on screen?

When we first learn elementary geometrical optics, the first thing taught to us is the two broad divisions of the type of reflection.-Regular and Irregular or Diffused. The difference in cause for ...
0
votes
1answer
120 views

Seeing the image as explained by Geometrical optics?

I was thinking about how the human visual system perceives the position of an object. I assume it essentially does this by focussing the incoming rays onto the retina and then judging from the power ...