Optical Definition and 640 Threads

The main evidence for the existence of dark matter is the flat rotation curve of galaxies, and high peculiar velocities of galaxies in galaxy clusters. The mass eclosed in a radius R is derived from the Keplerian equation M(R) = v2R/G . Also we know about the existence of gravitational...

Hello. Is there a way to calculate properties of a gas, given only it's composition? I.e. let's say i want to know what would a planet look like with an atmosphere of a mix of 50% gaseous sulphur and 50% gaseous mercury, at 500*C and surface pressure of half that of Earth. How would i go about...

Are there any real world uses for optical cavities. Optical (or laser Cavities) description: where lasers continually bounce off two reflecting mirrors.

Hi guys~ I have a question about lock-in detection method that commonly used in optical spectroscopy experiments, for example, the optical pump-probe reflectivity exeperiments on some semiconductor surfaces, or kinda like that. Usually, the sinario is: you use laser pulses, divided as pump and...

Homework Statement Describe what optical astronomers would consider the properties of an active galaxy and also describe what radio astronomers would describe as the properties of an active galaxy and explain how two sets of astronomers came up with these differing conclusions. Homework...

Hey all, does anyone know a link where I can find a c# implementation of a neural net that does OCR WITHOUT using libraries, I feel that OCR is a nice way to learn how neural nets classify data. Any help appreciated, thanks.

If we use 2 lasers with selectable light intensities as input, with each level of intensity corresponding to decimal number. Like level 0 intensity - decimal 0 (MIN) level 1 intensity - decimal 1 level 2 intensity - decimal 2 ... level 9 intensity - decimal 9 (MAX) and directly shine both of...

Hi, I'm trying to put together materials to demonstrate the Faraday Effect. I need to locate the supplier of some flint glass (glass with lead oxide or similar materials increasing the Verdet constant), that I could use in my lab. I had found this from Mansion Schools...

I’m looking to demonstrate destructive optical interference using a laser pointer. I’m splitting the beam with a prism and projecting the beams onto one point on the wall. Somehow I’m failing to get any effect, however. Setup: 1. I’m using a static laser pointer, a prism and a handheld mirror...

Homework Statement An optical fiber is one way to guide light efficiently from one point to an other. It is currently used for data communication: it offers low loss and very high bandwidth, ideal for the requirements of the internet. Generally, we can describe an optical fiber as a medium with...

-Hello everyone. At school, I studied about convex lense and concave lense. They are very interesting, we learned about how lights would be after going through the lense. But what I want to ask is how we can calculate the distance between optical center and focal (I means focal length). Focal...

Isaac Newton had an optical theory of gravity which you could make work with the light like corpuscles Newton never knew of, namely neutrinos So said my physics Professor once ... I wish there was a forum for discussing Newton's optical gravity theory, I think it could help explain ( the...

Caustics are singularities in the optical field: http://en.wikipedia.org/wiki/Caustic_(optics) I took this photograph of caustics created by the sun reflecting off of moving water today- The spatial pattern of spots is related to the (local) slope of the water: Each dimension in this image...

Homework Statement Given a "new type" of optical fiber (index of refraction n = 1.23), a laser beam is incident on the flat end of a straight fiber in air. Assume nair = 1.00. What is the maximum angle of incidence Ø1 if the beam is not to escape from the fiber? (See attached file for...

It says you can not change with lenses the value L - radiance. Below I have an example where it proves that you can or where am I wrong? (I made L for 2D case, in 3D case everything the same - L2>L1)

lets say someone had an idea for a fully optical computer; that had a optical cubic processor, that refracted and reflected signals. into a optical "motherboard" (except it was not a flat board, more of a rectangle), how would one go about writing a language for such a thing (lets say a base 8...

An optical low pass filter is supposed to blur the image using birefringence. I took out an optical low pass filter from a digital camera where it is used for anti-aliasing purposes. The filter looks just like a piece of glass. I pass a diode laser beam through it and look at the beam spot on...

I have a CW laser system, the optical detector receives a pulse width modulated signal and converts it to an analog signal. Both the source and detector have 32 channels and I would like to know what the analog signal power is, I thought maybe I could use the RMS voltage received on the...

I understand this that when an object is kept at focus of convex lens, then image is formed at infinity. So when we keep a convex lens above plain mirror and move object needle on the principal axis of convex lens and see a coinciding image with needle on lens and measure distance from lens then...

Hi I am looking at the problem of optical absorption in direct gap semiconductors. It seems like the perturbing Hamiltonian is an oscillating perturbation , ie. an electromagnetic wave. Why can't the problem be treated as the absorption of a single particle , ie. a photon ?

can you please let me know if this sentence is true about optical systems or not? "Diffraction may limit the resolution achivable by an optical system" Thanks.

Homework Statement A diverging thin lens and a concave mirror have focal lengths of equal magnitude. An object is placed (3/2)f from the diverging lens and the mirror is placed a distance 3f on the other side of the lens. Using Gaussian optics, determine the final image of the system after two...

Hi everyone. On these days, by watching solar panels and similar stuff, I just thought about it, and why they take such a wide surface to produce energy, and why their output is often low, as we all know. By navigating here on the internet, I've just seen a device called OPO (Optical...

Greetings, After getting some training I have access to my universities SEM facilities and I would like to image CDs and DVDs with it(, I know that these consist of many layer which may not be transparent to the e-beam so they might need some preparation. Does anyone have any idea? I am...

Which property is responsible for optical density In media

Hi, I am familiar with drawing rays through a lens. But when a few lenses are put together, things become confusing to me. For example, if a first positive thin lens at 0 forms a real image 10cm away, what would happen when we put a second positive thin lens, say at 5cm along the optical...

Hi I was working on delay-lines and I wanted to know if a pulse is delayed by 10 pulse lengths through a delay-lines than what is the corresponding storage bit for that delay line. Thanks

Homework Statement 2. Homework Equations 10 Log[10](g/mW)= GdBw The Attempt at a Solution I have attached a document of my approach to this question. I would like to know if my approach is correct? Thank you for your assistance

I am trying to understand the conditions for an optical resonator with unsymmetric reflectors, i.e. the focal lengths of the two reflectors are different. According to wikipedia (http://en.wikipedia.org/wiki/Optical_cavity#Stability) 0 < (1 - L/R1)(1 - L/R2) < 1 is the equation that will...

I need this information for a simulation I am working on that involves optical photon detectors. Specifically, I need a rough figure for how many photons a photon detector would register per second if I were to place it in ambient light from the sun. I realize that this number depends on the...

Hi all, Are there any good softwares for drawings schematics like this? I need to make and insert such images in my thesis report.

Hi guys, I was just wondering if any macbook pro owners have successfully converted the optical drive into an area to hold an SSD. I am planning on keeping my current HDD and adding the SSD. Please let me know how it went and how much it affected the performance. (2012 MacbookPro non-retina)...

Technically I'm supposed to have a total of 8 optical modes but only 4 of them were seen in a solid (by spectroscopy). So I suspect there's some degeneracies and symmetries involved, but I don't know which ones. I have two sets of assigned degeneracies: frequency; degeneracy set 1; degeneracy...

I see the term o"ptical frequency" in some articles. From Wikipedia I read that it means the whole EM spectrum. But something says to me it may be only the visible part of the spectrum. Now, which definition is correct? Thanks

Question Find out the total number of possible isomers with molecular formula C6H12 that contain a cyclobutane ring. Attempted Solution In Compound 3, Optical Isomerism is possible (geometrical isomerism is also possible but is neglected due to presence of optical isomerism) about both the...

It is said that a non-linear optical device may convert light into its higher order components. So what is the highest efficiency of the conversion? Can a non-linear device convert all input light into its higher order frequency? Thanks.

I'm stumped as to how many optic branches (modes) are present if there are X number of molecules in a unit cell and Y number of atoms in each molecule. I know that each individual atom has 3 degrees of freedom and more generally in a single unit cell, there are 3 acoustic branches (modes) and...

I'm searching for a week from now and can't find out difference between optical and geometrical length in optical path. Can anyone explain or give me idea or how can I find it out?

Hello colleagues So I've been trying to make head and tail of a paper concerning coherence holography. As I see it, it involves a sound understanding of the Van Cittrt Zernicke theorem I have linked the paper below, and I was wondering if someone could explain the physics going on behind and...

Hi all, I am wondering in the 3D optical transfer function as shown below: http://www.purplebark.net/mra/research/votf/otf-sliced-volume.png The m and n axes represent support of lateral spatial frequencies and the s axes axial. If we were talking about a microscope then it has what's called...

I'm confused about optical low pass filters (found on CCD imaging devices). As I understand it is a double layer of birefringent material which in effect splits light into 4: (2*25%) green, 25% red, and 25% blue (for a standard bayer matrix). The part I'm not sure about is if all 4 fall on the...

Can anyone tell me how to convert electrical lan signals into optical signals for wireless transmission via LEDs like they use it Li-Fi systems.

Homework Statement i can't understand why the optical path diffrence is 2nt+0.5λ. why is it so? the 0.5λ is due to the path difference change of 180 degree of when it is reflected lower ray when it is reflected from the lower glass surface... why there's also phase change of 2nt. since both...

Homework Statement for diagram 2 , i just can't understand why S1P -t + ut (upper ray ) is longer than the lower light ray (S2P) , ? if I take S2P minus ( S1P -t + ut ) , then i would get mt t (thickness ) is negative , which is indeed wrong! so it has shown that optical path of the upper...

Homework Statement In this question, when S2 is covered with a very thin glass, the fringe move toward Y . why is it so? Homework Equations The Attempt at a Solution

hi, What is the difference between radial polarization and optical vortex? thx http://en.wikipedia.org/wiki/Radial_polarization http://en.wikipedia.org/wiki/Optical_vortex http://en.wikipedia.org/wiki/Angular_momentum_of_light http://en.wikipedia.org/wiki/Orbital_angular_momentum_of_light...

I am trying to figure out a method for using optical tweezers to manipulate individual atoms into new meta-material structures. I understand this would require a very complicated process. I thought of some general steps this process might use. This is roughly what I think it might require...

Hey there. My goal is to understand the origin of the main forces that keep together an optical lattice created by two identical counter-propagating laser beams. I quote a small excerpt about the forces in optical molasses with high intensity, which I'm having trouble in understanding...

Wow! A physics forum! Here's the device I filed a U.S. patent for, so I'm wondering what to do next? http://www.youtube.com/watch?v=wYgfRzxc-Hs I've talked to the chair of my physics department and he said the amount of light arriving at each pixel is very small. CCDs are becoming...

I have a long tube (aout 30 cm) with a convex lens of diameter 7.5 cm on the one end and a small hole of diameter 2 cm on the other. When i shine a light through the hole and let it pass through the lens, i get a flowery pattern on the wall, looked very strange to me. There is a maxima in the...