Fresnel Definition and 125 Threads

Homework Statement Unpolarized light hits a flat glass surface, 37.5 degrees to the surface's normal. The reflected light's polarization is investigated with a polaroid. The relationship between the max and min value of intensity from the polaroid when it is rotated is 4.0. What is the index of...

In Feynman Lectures on Physics (you can find it online), chapter 33 of volume 1, the author derives Fresnel's formulas for the coefficient of reflection in an unusual way by making considerations about the different possible polarization of light. In this way he derives the squares of the...

Homework Statement For poisson's spot to be observed, how accurately circular must the stop be? How is the argument for the Poisson's spot changed if the light is either; white or spatially incoherent? Homework Equations The Cornu spiral for the circular aperture. The Attempt at a Solution...

Hi, I have a very simple test bench set up with a HeNe laser, followed by a spatial filter, then an Iris and then a couple of lenses. I can observe many fresnel rings on my image plane. Changing the size of the iris, and its distance changes the number of of rings. I would like to know why...

I was trying to determine the best oxide thickness and material for maximising the contrast of one atom thick material layer on top of silicon chip. Using Fresnel equations I was able to do plot the contrast with respect to oxide thickness and wavelength, but alas, contrast seems to be sometimes...

I have seen in many textbooks that the following Fresnel Equation \frac{n_t{cos(\theta_i)} - n_i{cos(\theta_t)}}{n_t{cos(\theta_i)} + n_i{cos(\theta_t)}} and then they say that via Snells Law we get the following equation \frac{tan(\theta_i - \theta_t)}{tan(\theta_i + \theta_t)} I can see that...

I would like to see the difference between Fraunhofer and Fresnel diffraction with a homemade setup. Has anyone achieved this? In this example, it seems that the main components are a He-Ne laser, a short-focal lens, a pinhole and an adjustable aperture. I have some doubts about the possible...

Hi all, Could you please help me understand the Fresnel integral and Green's functions? Could you please explain the Fresnel integral and/or Green's function like you would to at least a first-year undergrad? I have the goal of learning/gaining an intuition of the Fresnel integral and...

Homework Statement Please let me know if this kind of posting of exact problems from a textbook isn't allowed; if that's the case I'll delete it immediately. From Boas's Mathematical Methods in the Physical Sciences, Third Edition: The Fresnel integrals, \int_0^u sin (u^2)\,du and...

Hello, So my dad and I took apart our old TV that had a Fresnel lens inside. Unfortunately there is a crack near the edge due to a billiard ball accidentally being dropped on it. I was wondering how much this crack would affect the lens' ability to focus the sunlight into a point. When we...

Hello, 1. Homework Statement [/b] http://imageshack.com/a/img17/2531/gu44.png Uploaded with ImageShack.com[b] I'm trying to prove this but i didn't succeed Homework Equations The Attempt at a Solution For the t I multiplied by sin(θt) in the numerator and denominator and used...

Hello, I'm working with an automotive headlamp and I was asked to simulate a projection of this lamp onto a wall 25 feet apart. I know I need to use a Fresnel lens as a collector to achieve this, however I have many questions: 1. How should I choose the right Fresnel lens? 2. I need to...

Homework Statement Plane monochromatic light wave with intensity I 0 is incident normally on an opaque screen with a circular hole. What is the light intensity I of the screen at the point for which the hole: a) is the first Fresnel zone, the inner half of the first zone, b) made ​​equal...

Homework Statement Use the Fresnel Equations to prove that light incident at θp=1/2*∏-θt results in a reflected beam that is indeed polarized. Homework Equations N/A The Attempt at a Solution I cannot find a Fresnel equation that has θp in it. And even if I did, I wouldn't know...

I quote a unsolved question posted in MHF by user poorbutttryagin on February 5th, 2013.

Hi, I have an issue with the Fresnel amplitude coefficients. I know they are given in two versions, for s-polarization and p-polarization. A version for unpolarized (randomly polarized) light is available for the power coefficients - it's just an average - but I could not find such an expression...

Homework Statement A friend of mine asked me on the Fresnel approximations earlier, and I couldn't really remember many of the details other than it was an approximation for spherical waves based on the Taylor series. So basically I had to look it up in a textbook. One of the exercises...

Homework Statement Derive an expression for the Fresnel Zone Plate's focal length Homework Equations The fresnel zone plate has a transmittance function 1/2 (1+cos (ar^2)circ(r/2l)The Attempt at a Solution Using Eulers formula. this splits into e^(iar^2)+e^(-iar^2) Since the transmittance...

error in defined expression for Fresnel equation in MATLAB (urgent please )?? hi i have code for plotting Fresnel equation but there's something i didn't understand it and gives error >>((( plotopt - plotting option (type 'R' for plotting reflectivity, % 'A' for absorptivity or 'RA'...

So I'm thinking about Einstein's thought experiment in which an observer on a train has a clock that denotes time by bouncing light off a mirror and measuring the time for it to return. The setup is such that for the observer on the train, the light is traveling vertically - strictly...

Homework Statement A homework problem asks me to find the Fresnel coefficient for a linearly polarised plane wave, which is incident under an angle theta, whose electric field vector can be given as: E=Ecos\hat{s}+Esin\hat{p} \hat{s} and \hat{p} are the unit vectors for s-polarised and...

Hi I'm new here so I don't know if I posted in right place but here is the problem. I don't know if you are familiar with antenna theory but I need to calculate radius of 1. Fresnel ellipsoid. It's easy when two antennas are on same altitude but if they aren't there is a problem. If you...

When a ray interacts with a solid if the surface is polished reflection occurs. This is true even if the material absorbs at the specific wave lenght? In other words if the material absorbs at the specific λ, can occurs Fresnel reflection ? Or: Fresnel reflection has always all the same λs of...

Hi guys! Was wondering if anyone was confident with Fresnel equations for a refractive index interface. From what I understand: Assume incoming normal plane wave traveling in z-direction and polarised in x plane. Assume z=0 is the plane that separates two materials: n_1 and n_2...

Hello, whenever I come to the derivation of the Fresnel equations I get stuck on the boundary condition for the component of the E-Field that is parallel to the surface. I know for the parallel components Maxwell dictates that: E_{1t} = E_{2t}. For the parallel incoming light field...

Hi guys, I can't find my notes on Fresnel diffraction and I have my Optics exam on Monday... Does anyone know how to derive F=a2/λL where L=1/z+1/z' I've googled it to death, checked here and tried in Optics 4th edition by Hecht with no luck... I'd really appreciate any help...

need simulate program for fresnel biprism diffraction(urgent) Dear friends I am student learning phyisics (8th term or 4th year) this is my last term and I have optic My teacher told us that he want some programs to simulate some optice expriments like : prism - young expriment - loid...

Homework Statement Hey guys, I am part of a group building a solar oven. It will consist of insulated sides and a glass window on the top. Rather than using reflectors we want to salvage a Fresnel lens from an overhead projector to concentrate sunlight onto the glass window. Part of the...

Hi, I was wondering how come I can get a transmission coefficient higher than one? In the equation at normal incidence: t = E_t/E_0 = 2*n2/(n1+n2) > 1 if n2 > n1 How is it even possible to get a higher electric field amplitude out compared to the one that got in? I'd be very...

Homework Statement A zone plate is to be set up on an optical bench, where it will be used as an enlarging lens. Its innermost zone is to be 0.2250 mm in diameter and monochromatic blue-green light of wavelength 480 nm from a cadmium arc is to be used. If the magnitude of the enlargements is...

Hello everybody, I have a question about the Fresnel equations at normal incidence. My textbook gives the reflection coefficients as: (1) perpendicular polarization rs=( n1*cos(theta1)-n2*cos(theta2) ) / ( n1*cos(theta1)+n2*cos(theta2) ) (2) parallel polarization rp=(...

I want to maximize solar cell efficiency regardless of the sun's angle and so I've been looking at placing Compound Parabolic Concentrator (CPC) over the top of a high efficiency round solar cell. If I come up with a good design then I would like to try and manufacture some of them to see if I...

How could one measure degree of coherence with Fresnel biprism? Hello. I have some questions about the study of partial coherence with a Fresnel biprism. In common text degree of coherence and its relationship to visibility is introduced considering a Young Double Slit experiment. At the...

I know fresnel zone is related to ellipsoids but what are these about? I was told they represent most of the energy transmitted by an antenna to another antenna. However, this makes no sense to me. Apparently, the width of the ellipsoid increases if the wavelength does so as well which makes it...

In many books we can find the derivation of Fresnel Equations (TE and the TM reflection and transmission coefficients), but always for the case of a plane wave. How can we go about obtaining the reflection coefficient if the incident light took the form of a beam rather than a plane wave? We...

i am about to do a project on harnessing solar energy using fresnel lens. However, i do not understand how a fresnel lens works. Could someone please clarify how it works (how can it converge light despite having a flat face) and why does it have more converging ability than other lenses?

i want to do a project on solar water purification. I just saw a video on purifying water using fresnel lens. However, i haven't found any information on how one can make a fresnel lens suited to the purpose. So, how does one make a fresnel lens?

Hello :) I search for some specific info about fresnel lenses. I bought few so called "fresnel lenses" to play with light in my photography studio. I have both real fresnel lens (wide) and just magnifical foil (narrow). I want to project some pattern, so I put fresnel lens in front of...

Homework Statement A circular aperture, with diameter 3.1 mm, is illuminated by a monochromatic plain wave. On the screen, which lays 1m ahead, we observe that the center of the diffraction pattern is dark. When we start to move the screen gradually backwards, the center becomes bright, then...

Homework Statement The problem about this is, which Fresnel Equation am I supposed to use? Show that the brewster's angle is \tan(\theta)=\frac{n_{2}}{n_{1}} but which Fresnel equation do you use Problem: Using the correct Fresnel Equation using (plugging in) the transmitted angle...

Hi, I'm doing a question using the Fresnel power coefficients, not the Fresnel amplitude coefficients. We can use MATLAB for this, but we are given a fixed angle of incidence of 45 deg so its really just one calculation, as opposed to an earlier question where the angle varied between 0 and...

Hello, I have a 12x12" fresnel lens and I want to place a 14mm diameter fiber optics cable at the focal point to transport the light ~2.5 ft. Would there be any heat loss? And what percentage of the light would exit the fiber optics? Thanks, Fritz Laun

Homework Statement I've solved this question but I don't understand the conclusion the book says. Question reads: 2 towers(transmitter and receiver), both of equal height(10m) and separated by a distance of 500m. f=800Mhz. Calculate first fresnel zone First Fresnel zone has a radius of...

My first (successful) post, hope this isn't silly/trivial. Also hope this is the appropriate area for optics-related questions. While debugging some code that applies the Fresnel equations to transmission of light through multiple layers of planar media, I encountered an interesting feature...

Hello, all, I am using 9 fresnel lenses (~1x1' per lens) and 9 water blocks for a solar water heater. Each fresnel lens is positioned so that a water block below is heated. A pump is used to pump the water through the system. However, I have one question... I have all of my fresnel...

Fresnel zone radius calculation? this is a bit hard for me to find out the calculation 30 miles between HQ and Intermediate radio station. 19 miles between Intermediate radio station and Harbour Master Building. So, from HQ to Hardbour Master Building is 30miles + 19miles =...

I'm having trouble understanding the reflectivity and transmissivity (the ratios of energy reflected and transmitted through a boundary separating different media). Since energy is proportional to the square of the field, if you have a superposition of two fields at a point, to obtain the...

Hi there, I'm wondering if anyone has any analysis or sources to help me understand how a Fresnel zone plate can be implemented on a curved surface, and the corresponding diffractive efficiency and focal length?? Thanks!

Homework Statement All that is provided can be found through the following link: http://img33.imageshack.us/img33/6343/question2q.jpg Homework Equations No specific equations pertaining to solving double integrals. The Attempt at a Solution Ok, so I know that we cannot...

Hi Everyone, I am having trouble with my Fourier optics. I am trying to simulate Fresnel diffraction using the following form of the equations: Li(xi, yi) = K * magnitude (FT{ P(xp, yp)E(xp, yp) } p= xi/ld ;q= yi/ld) ^2 K = 1/(ld)^2 E(xp, yp) = e^(i*(PI/ld)*(xp^2+yp^2)) P is the...