Optical Definition and 640 Threads

I'm wondering about the Kerr Optical effect as described on wikipedia: http://en.wikipedia.org/wiki/Kerr_effect Are there limits to the range of parameters at which the effect starts to break down? What λ values and E values does this formula apply to?

Hello I am preparing a lesson on refraction and I've come across a confusing point. In a book I have read, it was said that the optical density of a material is proportional to the refractive index. That is, the greater the optical density, the greater the refractive index. I have however...

Homework Statement Problem: An object 2.0 cm high is placed in front of a diverging lens of focal length 1.8 cm. The object is 2.7 cm from the optical centre of the lens. Questions: 1) Where is the image located with respect to the focus and the optical centre of the lens, qualitatively? 2)...

Hi, I'm wondering if there's any possible way to do voltage gating to a sample while observing it with a microscope, in order to measure its optical properties while changing its electrical parameters. Thanks

If I have a 45 degree linear polarized light which I then circularly polarize using a 1/4 wave plate and put this through an optical rotary crystal and then using the equivalent 1/4 wave plate but in the reverse oriention, will I get back a 45 degree linear polarized light? Put another way...

Consider a Newtonian reflector telescope: As you can see in the image, the little secondary mirror inside the main tube is supported by an X structure called 'spider'. The four "legs" of the spider, called 'vanes' by astronomers, are actually thin stripes of high-tensile material, usually...

Hi, I am curious to know if there any passive (or simple active) methods to convert a very coherent signal into an incoherent one? I suppose I would need to find a way to chirp the signal and a non-linear medium might be one method. Any ideas? Thanks narra

Hi, I was wondering what the trade-offs were in having an optical gain (say with EDFA) compared to electrical gain (say with a PIN and transimpedance amplifier) of an optical signal. Thanks.

Hi all, I have only one spectrometer and 2 different light sources. I need to measure the optical power of the light sources. The spectrometer has a resolution of 8 nm. I measure the spectrum of each light source. And then calculate the optical power by integrating over the spectrum. My...

Can you advise me a free software that allow to draw rays passed throught system of thick lenses (preferable in 3D)?

Optical theorem says that total cross section proportion to elastic scattering amplitude in the forward direction.Then if the target is absolutely reflective ''mirror''(in the case of quantum mechanics:scattering potential=infinity(r<a) and de Broglie wave leng limits to 0),in this case the...

If you had to classify the above material under one of the below material categories which would it be? a) Ceramic b) Composite c) Metallic d) Polymer.

If we take a narrow aperture(such as the one used in the double slit experiments) and attach a length of optical fibre to it, surely now we know the position (confined by the width of the fibre) and also the momentum(defined by the direction of the fibre). How does the uncertainty principle...

According to the derivation of acceptance angle the first step is, The condition for Total Internal reflection(TIR) is sin(i)≥n2/n1, where i is angle of incidence in the core, n2= refractive index of the cladding and n1=refractive index of the core. sin(i(c))=n2/n1, where i(c) is the...

Optics would predict that objects appear bigger in size as higher the redshift and the density should be the same independent of the galaxys redshift. As far I know this is not supported by observations. Anybody has an explanation please? sdgs_cat

Ultra cold atom is achieved by laser cooling. For optical lattice, it is achieved by the interference of counter-propagating laser beams. What is the relation between Ultra-cold atom and optical lattice? Why do people load Ultra-cold atom in optical lattice? Thank you for your answer.

I 'm thinking to study about photonic and optical science, I always like the property of light and I want to study at the university Arizona. I want to know what is the good and bad side of this career because I am deciding, am I choosing a right career? Thanks.

Hi, I'm new on the forum and I would like to start with a question. I've searched for a reply in old posts with no success. If you can help me to find an answer I'll be very glad. Talking about optical modes inside a waveguide. If a waveguide support two different modes, say TM and TE mode...

How does reflection work in non-metals and metals? If you take, for example, a polished brass surface (or whatever really) and an incident photon, is the photon being absorbed and re-emitted by an atom at the surface of the reflective brass? If so, how is it that the re-emitted photon is...

What is an "Optical Mode". I've been reading a lot of solar cell articles, especially those having to do with nanophotonics. There is a term that I keep running into, 'optical mode', but I've yet to find an explanation that I can visualize or understand. What exactly is the "mode" being used...

can anyone please explain this property of silicon: An excellent oxide as the low-refractive-index cladding material. thanks

Hello, I use a 10x infinity objective as a condenser in a optical trap setup. The collimated forward scattered light is then focused with a 40mm lens onto a QPD. This is the imaging techqnique. There is also BFPI, and I am not clear on this method. My understanding is that I need to image the...

So my Google skills must be getting rusty because I can't find any good information on what Optical Engineers exactly do. I've narrowed it down to design optical systems.. and that's about it. I don't know the job prospects (are they in demand? are they too niche?). I don't really know what...

I am trying to gain a better understanding of physics outside of my classes. As such, I decided to buy myself an optical prism to learn more about the spectrum of specific light sources, light filtering, etc. I just received my prism in the mail today, but am severely disappointed. When I was...

Hi guys, Please suggest a good introductory books for Structural Geology and Optical mineralogy, thanks :)

I can't figure this out/find the answer. Why are acoustic phonons very low loss (i.e. earthquake P and S waves), but optical phonons die out rapidly? Thanks, Joel

Homework Statement We know that all meso compounds are optically inactive but is the reverse true? Are all optically inactive compouds meso?

Hello everyone! What materials are used for making optical filter glasses? I bought this: http://www.alibaba.com/product-gs/495852853/Digital_Camera_lens_43mm_950nm_IR.html and took its transmission spectrum. So, it reminds me a transmission spectrum of CdTe. But a-CdTe is more...

I'm trying to understand how optical circuits behave. In particular, if they can interfere "across time". Consider this optical circuit: Suppose that it is completely isolated from the outside world (until we check it), and that the detectors are time-insensitive (they record IF a photon was...

I've been looking on journals and textbook, as well as internet. Does anybody know if there is an equation to find out the value of direct optical band gap and indirect optical band gap? What is the difference of optical band gap, direct optical bandgap and indirect optical bandgap? also...

I'd like to know why a ray of light passing through the optical center of a convex lens does not get refracted at all. According to my knowledge, a ray of light will not get refracted if the angle of incidence is zero i.e. it is along the normal. With this in mind, I see how a ray traveling...

Homework Statement So the problem states that we have a (+) enantiomer of a coumpund with an optical rotation of 50*. If a pure sample containes 42% of the (+) enantiomer and 58% of the (-) enantioimer, what is the optical rotation value. (By * i mean degrees) Homework Equations I'm not...

Hi, When we use an optical microscope, how do we roughly calculate the illuminated spot size on the sample ? Also what is the light power on that spot? And what if I change to fluorescence microscope(epi illumination)? Cause the illuminating light go through the rear side of objective to...

Hi guys :) I'm designing an automatic soap dispenser, in which the soap particles contain phosphors. These will emit visible light in the presence of UV light. I intend to have a small UV light source underneath the dispenser. Thing is, its really bright in bathrooms, and its tricky to see...

Hi, A colleague of mine at work has this idea of using a focusing lens to focus the visible light into a optical fiber and guide it to some destination, e.g. room with no windows. I have no experience in optics, or in QED (only some "layman" knowledge of monochromatic light and its...

Homework Statement I need to find the refractive indexes of the core and cladding of an optical fibre by using the specs found here http://www.photonics.byu.edu/FiberOpticConnectors.parts/images/smf28.pdf Then I'm suppose to calculate the Numerical aperture and compare it with the one listed...

Optical traps for refractive colloidal particles (latex) of around 1 micron always employ a laser ligth tipically of 30 mW or even less. I have never seen a report of an optical trap using a non-laser light source. I wonder if is possible to build a non-laser light optical trap and if not why. I...

If an ultrashort optical pulse has a complex wavefunction with central frequency corresponding to a wavelength = 585 nm and a Gaussian envelope of RMS width of 6 femtoseconds, how can I calculate how many optical cycles are contained in the pulse width? Homework Equations The Attempt...

I was solving the following problem, and I've got confused at the second question http://img407.imageshack.us/img407/7921/43545856.png 1) An object is put at the center of curvature C of a convergent lens. Where is the image? Calculate by gauss equation. It's obvious that the image is in...

Hi! I have the following problem: the optical tweezers attract beads but when the beads get to the trap, they are repelled. Furthermore, when once in a while a bead gets trapped, it goes out of focus. The tweezers are coupled to an inverted optical microscope. They are made with an IR laser...

Homework Statement Hi I have a question regarding the force that it used in Optical Molasses. The force is generally given by F = \frac{\hbar k}{2} \frac{s_0}{1 + s_0+ (2\delta/\Gamma)^2} where s0 is the saturation parameter. The force saturates to F = \frac{\hbar k}{2} It is normally said...

I have an image taken with a camera. I know the f/#, focal length, CCD characteristics, and an approximate distance to my scene. I computed the modulation transfer function but I am trying to map the pixel space to cy/m and having trouble. I essentially want to determine the cutoff spatial...

Hello, I am trying to determine the band gap of an amorphous material (a glass sample) and I read that you can do this from the determination of the optical absorption edge. From this kind of measurements you fitt an equation of the type (αhν) = B (hv-Eo) 2. my question are: 1 - is it...

Hi, new to the forums, nice to meet you folks, etc. Today the English wikipedia featured a picture of Tracy Caldwell-Dyson in the cupola of ISS(http://en.wikipedia.org/wiki/File:Tracy_Caldwell_Dyson_in_Cupola_ISS.jpg). In that picture the arc of Earth/space boundary is visibly distorted at...

Homework Statement In the attachment below, a ray of light undergoes total internal reflection in an optical fiber such that the angle θ between the ray and the interface is 47°. Assuming the fiber is surrounded by air, what is the minimum index of refraction necessary for this to occur...

Of course we all know the standard symbols to use when drawing electrical circuits, but is there an analog for optical setups? I'm working of a poster and most of the symbols I'm using are just boxes with labels next to them, or just lines for mirrors and lenses.

Hi. I am new to PF. I am an incoming high schooler with an interest in astrophysics, and a friend and myself are working on building a telescope (not a very sophisticated one, just one that can reveal the craters of the moon and the satellites of Jupiter). I am curious to know if any amateur (or...

Assume you have a sinusoidal 500THz function generator and assume you have a compatible antenna. If you feed the signal to your antenna, is optical phenomena observable ?

Homework Statement 1. I have been recently wondering how is data stored on and retrieved from optical devices like CDs, DVDs, and Bluray. What makes these different storage types different from each other? 2. Why will a silver mirror not show a reflection when you sand the surface with...

I have been recently wondering how is data stored on and retrieved from optical devices like CDs, DVDs, and Bluray. What makes these different storage types different from each other? Why will a silver mirror not show a reflection when you sand the surface with very coarse sandpaper? Is it...