Cavity Definition and 260 Threads

Homework Statement Calculate the Q value for a krypton laser with λ=0.569 microns, 0.568m cavity and mirror reflectance of 100% for the rear and 52% for the output window. Homework Equations For a laser cavity=> Q=(4πL)/(λ(1-R1*R2)) The Attempt at a Solution Q= (4*π*...

Homework Statement If I have a solid sphere of radius R and charge density +\rho \, C/m^3 and I then remove a smaller sphere of radius b and is a distance a from the center of the larger sphere, what is the electric field inside the cavity? I get an answer which I think is right. I've look...

Hi, I am a graduate student with a background more oriented in high energy physics and cosmology but switching to light and matter interaction, more specifically cavity QED and quantum optics. I need to have a working knowledge on those topics, being able to read state of the art articles and...

Homework Statement A conductor, maintained at a potential V, contains a spherical cavity of radius R. A point charge q is placed at a distance a ( a < R)from the center of the cavity. Find the potential of the electric field in the cavity . Homework Equations I was considering using...

Hi In cQED and the Jaynes-Cummings model, three parameters are usually introduced which describe the atom-cavity system: The radiative lifetime γ, the cavity linewidth κ and the pure dephasing rate 1/T2. However I am not that familiar with the latter parameter. Basically I guess it describes...

Hi, I calculated the electric field of a sphere of radius r with a volumen density charge \rho and also it has inside of it a spherical cavity and its center is situated in r/2 with radius r/2, so I calculated the electric field of the sphere with the cavity inside and I get E=\frac{\rho...

The electric field in a cubical cavity of side length L with perfectly conducting walls is E_x = E_1 cos(n_1 x \pi/L) sin(n_2 y \pi/L) sin(n_3 z \pi/L) sin(\omega t) E_y = E_2 sin(n_1 x \pi/L) cos(n_2 y \pi/L) sin(n_3 z \pi/L) sin(\omega t) E_z = E_3 sin(n_1 x \pi/L) sin(n_2 y \pi/L)...

Hello, How does an external cavity laser produce ultra narrow line width when it's larger cavity should reduce the free spectral range and thus introduce more longitudinal modes? Thanks.

Homework Statement You are given a 10cm Cube of aluminum with Density of 2700kg/m is submerged in water and the weight in water is 13N. If a cavity exist how big is it? Homework Equations The equation i used were B = V * P_water * g to find buoyancy. To find the enclosed cavities i...

Hi there people I'm going through some old notes and have become a bit confused... I'm looking at the energy density of e.m modes in a cavity I have that (energy in the range ω to ω+dω) = (mean number of quanta per mode) x (energy per quanta) x (number of e.m modes in the range ω to...

There is a spherical lead ball with a spherical cavity. It is heated. The size of the cavity increases. Why does it do so? Also, does it matter what happens to the cavity if it is not present at the centre, but rather a little removed from the centre? Will it remain spherical?

If a conducting sphere having a cavity inside it is placed in an electric field then what will be the field inside the cavity?And is there any charge induced in the cavity?I have many doubt about it give a good discussion about it.. :confused:

Hi Consider the case of a charge placed inside the cavity in a metal. Let the charge be at A. Assume that the cavity is some weird geometric shape so that one point on the inner surface of the cavity is closer than some other point. Let point B on inside wall be closer to the location of...

Homework Statement We are given an infinitely long cylinder of radius b with an empty cylinder (not coaxial) cut out of it, of radius a. The system carries a steady current (direction along the cylinders) of size I. I am trying to find the magnetic field at a point in the hollow. I am told that...

Homework Statement Suppose that a particular x-polarized cavity mode is described, at time t = 0, by the state |ψ(0)> = (1/√2)(|n> + |n+1>) Find |ψ(t)> for t > 0. This is best done in the Schrodinger picture. Evaluate the expectation of the electric field operator Ex and the uncertainty...

Hi Does anybody know of a good book on cavity QED? It seems that most books only have a small part of a couple of pages covering the subject. Niles.

Homework Statement Consider a sphere uniformly charged over volume, apart from a spherical off-center cavity. The charge density is ρ, radius of the sphere is a, radius of the cavity is b, and the distance between the centers is d, d < a-b. (a) Find the total charge and the dipole moment...

Homework Statement No specific question, I'm a greenhand to waves, so when it came to sound cavity, I was just confused how the teacher(in the video lecture,I'm not a physics major) can distinguish which side is a node and which is an anti-node, it seems too fast for me, could anyone give me a...

Hello there, could anyone help me with a certain basic problem in relativistic QM? What would be the wave function of a photon (or generally a particle with zero rest mass) in a spherical 3D cavity, having potential energy V=0 within the cavity and V=k outside the sphere (k>0)? I have been...

Hello everyone, Recently I have been studying cavity resonators. I noticed that all cavity resonators have air in them, but I was wondering what the effects would be if something other than air was used? For the sake of simplicity let's say we put a dielectric material in it with a...

There's a metal plate with a circular hole/cavity in it. Consider its width negligible. Now the plate is uniformly heated. Textbook says that size of hole/cavity increases along with the dimensions of the plate. But my intuition says dimensions of cavity should increase and size of hole/cavity...

Hello guys, I've been trying to solve Maxwell's Equations in a laser cavity, with length L. However I cannot... I've searched over the net to find a proper solution but I couldn't. I started by taking a field E(x,y,x,t)=E0 e(x,y)e-jw te-jb z. I take the phasor E(x,y,z)=e(x,y)e-jb z and...

Homework Statement This question has already been asked before. The electric field inside a spherical cavity carved out of a larger sphere is uniform which I have derived. What I don't really understand is that if you construct a gaussian surface inside the cavity, it wouldn't enclose any...

Homework Statement Assume that there is a single blue photon in a cavity of the size of 10 micrometers. The total energy of oscillating electric fields due to this photon is one half of the photon energy. A. Estimate the magnitude of the electric fields associated with this single photon...

If EM waves are pumped into a resonant cavity at it's resonant frequency will each incoming wave add it's energy to amplify the wave(s) in the cavity? I know that if you pulse a light source into a circular wave guide and you pulse the light source each time the light wave returns to it's...

Hi, I am trying to calculate maximum E-field strength in a rectangular waveguide cavity resonator at 1.6GHz. The input power is 200W while the resonator should wsupport TE101 mode. cavity dimensions are 0.131mmx0.65mmx0.134mm (WxHxL) having lossy walls made up of copper with conductivity of...

It is perfectly possible to derive, for instance, the Maxwell distribution of speeds in a heuristic way with only two things: 1. The Gibbs hypothesis, which says that to count the number of states at speed v you take all the points in phase space between v and v+dv in velocity space. This...

This is an excerpt from my textbook. Could someone please help me understand why the line I highlighted in yellow is true? Thanks! :)

Homework Statement The polarization charge in the surface of a spherical cavity is -\sigma_e \cos\theta ,at a point whose radius from the centre makes and angle \theta with a give axis Oz. Prove that the field strength at the centre is \frac{ \sigma_e}{3 \sigma_e} parallel to Oz. If the...

Could a cavity magnetron be done in reverse in a way so that the em waves would interact with the magnetic field and give electrons energy to jump from a cathode to an anode and would any resonant frequencies be involved? I've read some where that this is why metal articles should not be put...

Homework Statement The polarizatiob charge on the surface of a spherical capacitor is -\sigma_e \cos(\theta), at a point whose radius vector from the centre makes an angle \theta witha given axis Oz. Prove that the field strength at the centre is \frac{\sigma_e}{3 \epsilon_0}, Homework...

Hi all I have a revision question I am having some trouble with A cold room has a wall measuring 5.2m by 2.5m. The wall is constructed of 120mm thick brick on the inside, a cork layer 80mm and a 30mm layer ow wood in the outside. the inside temperature is -4ºC and the outside temperature...

Our sound will be like "Donald Duck" if we inhale helium gas and the explanation from web is because" The cavity resonances which determine the vocal formats would be raised by the higher sound speed,"(http://hyperphysics.phy-astr.gsu.edu/hbase/sound/souspe.html). Why cavity resonance raise as...

Homework Statement Suppose there is a cavity inside a metallic conductor...And say a chrge q is placed inside it...Now a charge -q is induced on the inner metal surface and a chrge q appears outside... Homework Equations The Attempt at a Solution Now i have two questions ...

I'm not entirely sure if this is meant to be in the "advanced physics" section, it's for my undergraduate degree anyway. Homework Statement A conducting sphere of radius R, carries a total charge of q. It is surrounded by an electrically neutral conducting shell with an inner radius, a, and...

Suppose we had an uncharged solid spherical conductor with radius R, and some spherical cavity of radius a that is located b units above R, where a+b<R. If we place a charge inside the cavity at the center, how would you quantitatively express the E-field lines outside of the conductor?

hello I am a new member in this forum , and I want to learn well with you...sorry I speak little English,so I use google traductor , i speak french , but with french unfortunately there is a little information! now what is a cavity resonant ? and how to write equations for field within...i...

The rms EM field within a cavity resonator, excited in a single resonant mode by a current probe of fixed rms amplitude, is known to rise linearly with time; eg. http://www.jpier.org/PIER/pier78/15.07090605.Wen.pdf", sections 5.2, 5.3, fig's. 6, 10. (Normally it is a fixed driving voltage...

Homework Statement I am trying to find the force acting on a charge placed a distance r0 from the center of a spherical cavity of radius a. The entire cavity is immersed in a dielectric material, epsilon2. Homework Equations The Attempt at a Solution Here's my quandary: I can find the...

How to calculate the fraction of stimulated photons that escape from a laser cavity with alpha=0.1 cm^-1 length of cavity=1mm refractive index of laser cavity=3.2 the photons are assumed to be escaping into air so approx refractive index is 1. Im assuming that alpha is some sort of...

Hi, I'm here for help and hope somebody could give a hand on this because I'm noob in this. I'm now constructing a MATLAB program to find Electrical field and potential within a square grid mesh with square cavity inside. like the picture above. I only manage up to this...

So I'm about to construct a TE102 microwave resonator from folded copper sheeting. I'm planning to fold a U shape and join it to the last side with silver solder. Is this going to work well? I'm planning on making good physical contact through accurate folding, and then securing the pieces...

Hi, I'm having trouble understanding where the formula (appearing in my notes or Wikipedia) comes from. One can read on Wikipedia: The phase difference between each succeeding reflection is given by \delta = \frac{2 \pi}{\lambda}2nlcos\theta Where n is refractive index inside cavity, l...

Homework Statement I got this problem (Sectional image of a cylinder): http://img715.imageshack.us/img715/3448/cylinder.jpg Besides that I know that the cylindrical conductor is infinite long, and the same is the cavity. And through the conducting material there is a current density that is...

Homework Statement A charge q is uniformly distributed over the volume of a solid sphere of radius R. A spherical cavity is cut out of this solid sphere, and the material and its charges are discarded. Show that the electric field in the cavity will then be uniform, of magnitude...

we know that vector potential in a resonator satisfies the equation \intA(\lambda)A^{*}(\lambda^{'})dV=4\pic^{2}\delta_{\lambda\lambda^{'} So how about in cavity of arbitrary shape? Does this equation still valid? Thanks!

Homework Statement Use the divergence theorem to find the outward flux of a vector field F=\sqrt{x^2+y^2+z^2}(x\hat{i}+y\hat{j}+z\hat{k}) across the boundary of the region 1\leq x^2+y^2+z^2 \leq4 Homework Equations The Gauss Divergence Theorem states \int_D dV \nabla \bullet...

A uniformly charged sphere (center 0,0) with radius 2a and volume charge density \sigma has a cavity within it (center 0,a) with radius a. Show that the electric field within the cavity is uniform and Ex=0 Ey=\frac{a\sigma}{3\epsilon} where \epsilon is the permittivity of free space. Hi, I...

One of my professors made an X-band cavity resonator by putting together, end to end, two X281A coaxial waveguide adapters (n-type) with cut center pins. It works pretty well - but I need some more information. Does anyone know where can I find some more information on this setup...

Homework Statement I have : Spherical conductor of radius=x; Spherical conductor has a inner cubic cavity of side = b; inside the cubic cavity we have a charge = y; the surface of the sphere has a charge density = z; I need to calculate the electric field at some point g, where g>r...