Optical Definition and 701 Threads

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...

Optical density of an atomic ensemble and its linewidth Hi I've been thinking about something for a while now. If I take a two-level atom, completely at rest, then I can probe it with a quasi-resonant laser. The absorption of the atom is a nice Lorentzian, nothing fancy here. However, now...

Homework Statement Optical System: Biconcave lens and convex mirror separated by distance 'L'. Object placed 0.40m in front of the lens. Final image is .12m from the vertex of the mirror Lens curvature radii: 0.10m and 0.20m Mirror curvature radii: .12m Calculate the distance 'L'Homework...

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...

Hi all, On p.327 in my second edition of Peskin and Schroeder, I have an expression for the one loop correction to the 4-point amplitude of phi^4 theory: i\mathcal{M}=-i\lambda - \frac{i \lambda^2}{32 \pi^2}\text{[Complicated integral]} Mathematica can do the integral for me, and all that...

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...

Hello, I am wondering... If you have two ethylenediamines (en) oriented in a cis en-en fashion, will they always have an optical isomer? I have not found a case yet where they do, and it would probably save time to assume optically active in an environment presseed for time (such as on a...

First, I hope this is posted in the correct section, and I'm sorry if it isn't. I am looking to create diagrams of optical setups for a technical paper. My mentor recommended using Microsoft PowerPoint, but my diagrams don't compare to those in published papers. Is there a better program...

What is the effect of using other than 1550nm light with an (LiNbO3, lithium niobate) electro-optic Mach-Zehnder modulator? Thanks!

Hi all, I just joined this Forum to get an answer to a question really, it's not for Collage or Uni or anything just a curiosity really. Mathematics isn't one of my strong points and I hope this is in the right section. What I'd like to know is... If an Object is 3 miles away, and this is what...

Hi, fellow physics friends! I'm doing a small interior decoration project in which I need optical image rotation as a component. I know that this can be done (see e.g. http://www.optics.arizona.edu/optomech/papers/swift%201972.pdf for a review paper). I've also seen Half-Penta Prisms sold...

Hi, I'm attending a 50+ Liberal Art college in physics and math, double major, I'm going to be a senior this fall and want to go to graduate school. I have major GPAs 3.81, 3,73 for physics and math respectively and 3.57 overall, GRE 670+800. I also conducted research at ORNL at material...

Hi I am not sure whether the object plane overclaps focal plane in a infinity-corrected optical microscope. Thanks!

Problem with opticalmicroscopy of features near vertical sidewall of very deep trench Hi, I posted my question here: physicsforums.com/showthread.php?t=612780 but there may be more specialists here. Essentially I have a feature right next to a very deep vertical sidewall of the deep...

I just did this lab where I measured the absorbance of nucleic acid solutions and I have to find the concentration (in mg/mL) of each nucleic acid at different temperatures at 260nm. It is given that they have an absorption maximum at 260nm with an intensity of 17 OD (optical density) units/mg...

The starting point for special relativity is the thought experiment. These experiments generally describe two different observations of a single event, and the experiments assume that both observations are true. To be clear: the assumption is that both of the different observations of one...

Hi When introducing optical molasses, the polarization of the counter-propagating beams are never taken into account. Is it really correct that the polarization of the beams are irrelevant, when trying to reach the Doppler-limited temperature? Niles.

HI, I am looking for the ''Physics of Quantum electronics vol.8 chap.5'' I could no where find this book /journal or the conference proceeding . does anybody have an Idea How can find this ? well this is the exact information That I am looking for ...

Whats the job market like for someone with only an undergrad B.S. in say Physics vs EE vs Optical Sci/Engineering? I'm especially intersted in optical design opportunities around North America.

Homework Statement A thin lens of focal length f is used to collimate the light emerging from two different optical fibres. When used with a first fibre of small core diameter and numerical aperture NA it acheives a diffraction limited divergence of θ1 for the collumated beam. Find the...

Hi I am trying to design a three mirror off axis telescope. The free parameters are the offset between the apertures and distance betwen the surfaces. My question is for a system with 'n' elements/surfaces (n=3 in my case) is there a relation between optical path length and focal length of...

If a surface is perceived as being white because it reflects all wavelenghts of visible electromagnetic radiation, how does this differ from a mirror surface which also reflects all impinging light? How is a mirror different from a white surface i) optically and ii) at the level of condensed...

This equation is for calculating what and how was it obtained. E=6(mg/bt3)Rs

Problem: My homework constantly refers to something called the optical path length, L - I'm not exactly sure what this is. It's in the equation below. This question is in relation to astrophysics and dust extinction in the Interstellar Medium. Relevant equations: Dust optical depth, τλ =...

Hi I have a question on AOMs used in a double pass configuration. I understand the motivation for such a setup, but what I don't quite understand is the following: During the first pass, the frequency of the incoming beam is changed from ω to ω+Ω at an angle θB. Then we send the diffracted...

Who can tell me the concept of optical lattice and quantum dot? Or give me an advice of some thesis? Thank you very much.

Hi Say I am looking at an AOM working in the Bragg regime (i.e., only a single diffracted beam). It is easy to show using Bragg's law that the frequency-shift Ω of the diffracted wave is given by \Omega = 2n\omega \frac{v}{c}\sin(\theta) Here Ω is *also* the frequency the AOM is driven with...

Hello Forum, what type of image does an afocal system produce if the object is an extended object? A real or virtual image? Any example? Say a car is located 30 meters away... Thanks fisico30

Hi When the dielectric function of a system is time-invariant, solutions of Maxwell's Equations are separable and they are usually written as (I only write the E-field) E(r, t) = E(r) \exp(-i\omega t) Now, in my book they write an optical field as E(t) = E_0\exp(-i\omega t) +...

Hi. I am going to start my MSc in a couple of months majoring in nonlinear quantum optics. I have a good basic in quantum mechanics, but have never looked at quantum optics before. My topic will be to investigate quantum properties of nonlinear optical coupler but i have problem with the...