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

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120
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8k views

Why do sunbeams diverge even though the sun is much more than a few kilometers away?

Consider this picture of sun beams streaming onto the valley through the clouds. Given that the valley is only (at a guess) 3km wide, with simple trigonometry and the angles of the beams, this ...
2
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3answers
125 views

Does polarization remove any of the fields completely?

A light is made up of electric and magnetic fields oriented perpendicular to each other. Can polarization lead to the removal of any of the fields completely?
0
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1answer
798 views

Ways to measure the focal length of a convex lens with only natural sun light [closed]

What are the common ways to measure the focal length of a convex lens with only natural sun light?
0
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2answers
191 views

Gaussian beam modelling, location of the beam waist?

In reference to the specifications of a laser diode below: http://www.thorlabs.de/thorcat/11900/L780P010-SpecSheet.pdf I wish to be able to model it as a gaussian laser beam. I understand there is a ...
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1answer
125 views

Does the distortion of an image depend on the location of the object with respect to the mirror?

A mobile phone lies along the principal axis of a concave mirror with its distorted image, as shown in Fig. How do we actually figure out the formation of such images? The answer says: "The image ...
2
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0answers
43 views

Ray tracing a three-way intersection

I've been studying ray tracing in media with linear velocity-depth functions. One of the key concepts I've come across is the ray parameter, and in particular the idea that the ray parameter is ...
0
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0answers
197 views

Gaze tracking with the pupil-glint response how does the geometry work?

I am struggling to understand the geometry behind the pupil glint response (see above) (With only one light source). I understand that you use the glint to find the corneal centre (Centre of corneal ...
0
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0answers
24 views

Does dispersion take place in our eyes? [duplicate]

What do we see if a single ray of white light falls in to our eyes ? Doesn't it undergo dispersion ?
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2answers
71 views

Object inside the eye

What will be the image seen to us if an object is placed in between the focus and pole of our eye lens ? I guess no image will be formed.
2
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0answers
76 views

how can a lens combination take virtual object to the second lens?

When two lenses are in combination. what logic is it to take the image of first lens (which is not formed in real) as a virtual object to the second lens ?
0
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0answers
212 views

Geometric optics question

This question appeared on this site Q17: here A concave mirror is broken into two parts and these parts are separated by a distance if 1 cm. The focal length of the mirror is 10 cm. Find the ...
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0answers
99 views

Using aluminium foil as a reflection for UV at 240nm [closed]

Will aluminium foil or sheeting reflect UV light at 240nm being used as a disinfection cell for bacteria in water.
1
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1answer
173 views

Issue on sign convention with optics

I have a problem understanding the sign conventions used in the equations that describe the imaging properties of mirrors - in particular, when and why should I use a positive or negative number for ...
2
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2answers
278 views

Interferometers and Earth's motion relative to the Aether

Why was the Michelson and not the Fabry-Perot interferometer used to detect the motion of Earth relative to the Aether? Maybe the Fabry-Perot was used but we all know that the most famous experiment ...
1
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1answer
305 views

Ray diagram of infinity well

An infinity well works on the principle that when two plane mirrors are placed in front of each other an infinite number of images are produced thus creating an illusion.I am a bit confused about it's ...
2
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1answer
368 views

Good resource for geometric optics

I'm looking for a good resource (preferably a book) on geometric optics. I am thorough with the basics (the mirror formula, lensmaker's formula, thin lens formula, etc). What I want is something that ...
3
votes
0answers
158 views

Why isn't Zemax showing a tilt on the wavefront on my telescope design?

Attached is a Zemax file Zemax File for an afocal telescope system. When i tilt the field by an angle of 2 degrees (In green) I would expect a wavefront tilt at the "Image " plane, however when I ...
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0answers
41 views

Increasing the volume of a object in a photograph

I have two images which look like this --- These images are two views of a calibration object --- the white die that you see hanging in the middle. The problem is that, the die is too small and ...
1
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0answers
191 views

Two thin lenses in contact [closed]

Two thin lenses with same focal length are in contact. what is the resultant focal length? Options a) f b) 2f c) f/4 d) 4f My Answer By both plotting the light ...
1
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2answers
274 views

light ray undergoing total internal reflection thrice inside a prism

Can it ever be possible that a light ray going inside a triangular prism of refractive index n having refracting angle A undergo total internal reflection thrice before emerging out? Note:I know it ...
1
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1answer
187 views

Wavefront sensor specifications Shack-Hartmann

Why is the dynamic range of Shack-Hartmann wave-front sensors (As seen in the first image below) quoted in wavelengths and not in angles? I thought that one of the most important aspects of the ...
1
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0answers
49 views

Can multiple lasers be concentrated in a circular area using some optical arrangements?

Can multiple lasers be concentrated in a circular area using some optical arrangements such as using a paraboloid surface? If yes, why do in high laser power systems do they use only 2D arrays of ...
0
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0answers
192 views

Changing light beam direction

I'm using a rotating mirror to reflect a beam of light like that: where A is the beam source, B is the projection of the reflected beam on a surface at a distance y from the mirror, x is the ...
3
votes
2answers
408 views

Shack-Hartmann wavefront sensor concepts, pupil conjugate planes?

I am just starting to looking at the application of wavefront abberommtery to measure abberations in the human eye. I am confused over the pupil conjugate planes, do you use relay lenses to image the ...
1
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1answer
124 views

Fresnel Rhomb Retarder specifications

In my homework I have a Fresnel rhomb retarder and I am asked to calculate the retardance. I have the refractive index in terms of the wavelength(dispersion equation) and the phase difference incurred ...
29
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4answers
3k views

Is it possible to focus the radiation from a black body to make something hotter than that black body?

My previous question wasn't specific enough. I'll try to be more specific. Let's imagine we have a hot body let's say 6000K hot that emits lots of thermal radiation. Let's assume 1kW of radiative ...
72
votes
5answers
8k views

Is it possible to start fire using moonlight?

You can start fire by focusing the sunlight using the magnifying glass. I searched the web whether you can do the same using moonlight. And found this and this - the first two in Google search ...
0
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0answers
301 views

Off-Axis Parabolic Mirror Elliptical Collimated Beam Shape

When you collimate a point source using an off-axis parabolic mirror (OAP) with a circular shape, the beam area of the collimated light becomes more and more elliptical (x-dir. is smaller than y-dir.) ...
2
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0answers
146 views

Why the Caustic of a circle is the most bright curve in the circle?

Caustic of a cirle is the envelope of light rays reflected by a circle, which is the most bright curve in the circle. But why? Here is the picture shows the Caustic of a circle.
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2answers
1k views

How to Ray Trace Chief and Marginal Rays in Thin Lens Systems

Looking at the below images, the chief and marginal ray appear to be modeled just fine. But, those lines don't seem to conform to the rules typically used in thin lens ray traces. An example of ...
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1answer
85 views

why an immersion lens is called so in Ion Optics?

In Ion Optics, an immersion lens is composed of two planar apertured electrodes. My question is why it is called an 'Immersion" lens? I know that an Einzel lense has three or more electrodes. But ...
2
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1answer
565 views

Keplerian Telescope Exit Pupil Location - Whats the Basis for It's Formula?

For a simple two lens Keplerian telescope, this is the formula for the location of the exit pupil: $$z'=\frac{f_2}{f_1}(f_1+f_2)$$ Where $z'$ is the distance to the exit pupil location (i.e. eye ...
1
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1answer
389 views

Problem in ray diagrams in convex mirrors

I just found out about the Desmos online graphing calculator, and it is really a very nice tool. Just while playing with it, I had the idea of creating simulations. I decided to make a simulation of ...
3
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2answers
345 views

Is there a mathematical equivalence between gravitational optics and quantum optics or are they mathematically incompatible theories?

I know that massive gravitational bodies will curve the path that light travels. I think that quantum optical mediums also bend light. I am still confused of whether quantum optical mediums actually ...
0
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1answer
60 views

How to zoom and focus image from object at fixed position on fixed screen?

Suppose there's an object located at some position $x_O$, which emits light in the direction of sensor screen located at $x_S$, and the screen has some lens nearby at $x_L$, which partially focuses ...
2
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1answer
528 views

How to calculate the refracted light path when refraction index continuously increasing?

Suppose an incident light from vacuum ($n_1=1.0$) into some media ($n_2=n_1+\mu\; x^2$) as in the figure below. How to calculate the refracted light path curve in closed form? Update: Try to set ...
2
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1answer
104 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
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2answers
72 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 ...
3
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1answer
75 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
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0answers
54 views

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

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
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2answers
1k 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
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1answer
2k views

Distance between Newton's Rings fringes is does not seem linear

On the outer edges of Newton Ring patterns, the fringes are really close together, and much more uneven. Also, the spacing does not seem to decrease linearly at all as you move from the center. Why is ...
3
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1answer
68 views

Measuring parallaxes from the moon

If one were to measure star parallaxes from the moon, what (if any) changes would you have to make compared to someone making the calculation from earth? What about on another planet in our solar ...
0
votes
1answer
40 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
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1answer
37 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
224 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 ...
0
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2answers
311 views

Ray tracing in a inhomogeneous media

If I have an optical transparent slab with refractive index $n$ depending on the distance $x$ from the surface of the slab, the refractive index can be described by: $$n(x)=f(x)$$ where $f(x)$ is a ...
1
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2answers
200 views

Ion Optics: Electric and Magnetic field. A comparison with Light Optics

When we compare ion optics with light optics, normally we consider electric field. For example Snell's law. $n_1\sin\theta_1$=$n_2\sin\theta_2$. When an electron move from one electric potential to ...
5
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3answers
505 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
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2answers
557 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 ...