Recent content by IcedCoffee

Thank you! So when a transmitter has a phase so that the wave it emits interferes destructively with the external field, it would rather absorb the external field I believe?

Thanks a lot! And I guess that explains why the required energy increases linearly with external field.

I'm trying to wrap my head around the energy increment under constructive interference. In short, why does energy increase quadratically when each source emit EM wave that interferes constructively? Suppose we have an array of identical and equidistant sources, each of which span the entire x-y...

There seems to be some difference between "field autocorrelation" and "interferometric autocorrelation" - the latter uses second harmonic generation while the first directly measures the pulse itself. As for the reference, I couldn't find the detailed derivation but I believe taking an...

Intensity autocorrelation uses second harmonic generation from two non-collinear beam. It cannot resolve the fringes of a multi-cycle pulse. Interferometric autocorrelation uses two collinear beam. The generated second harmonics beam is thus collinear with the two beams, and is affected by...

I know that from intensity autocorrelation, I simply need to divide the FWHM by 1.53 for sech2 pulses. But I can't seem to be able to find any reference on how to get pulse width from interferometric autocorrelation signal. Can someone help me?

Found it: https://physicsisbeautiful.com/resources/thermal-physics/problems/4.15/solutions/4.15.pdf/fs8GhQ3hnKFu2t8QkKQPEM/

Here's a picture: Since the entire cavity is in a steady-state, the energy leaving through the circular hole of radius ##\delta r## per unit time must be equal to the energy crossing the hemisphere ##S_2## per unit time. (I guess we are also saying that the medium does not exist between...

In Principles of Lasers by Svelto, while deriving the Planck radiation formula, equation 2.2.3 says $$I_{\nu} = \frac {c_0} {4n} \rho_\nu$$ where ##I_\nu## is the spectral intensity at some hole in the cavity wall (energy per time per area per frequency), ##c_0## is the speed of light in...

I'm wondering what the relationship between blackbody radiation and spontaneous emission is. As far as I know, there are three sources of EM radiation - thermal radiation, oscillating dipole (multipole?), and LASER. And it seems like light emission from an atom can be separated into two...

Thank you for your reply! The Wikipedia page was really helpful too. So can I say that CW analysis of a structure is only valid when the structure's dimension is smaller than the temporal coherence length of the pulse?

I get that a single (optical) pulse is a superposition of continuous frequency components of its spectrum, but I'm a bit confused how Fabry-Perot interference can be interpreted in time domain. In a single-frequency explanation, the idea is that the incident wave goes through multiple...

Ah, I see. It's on a midpoint between two atoms like (2.5, 1.5, 0.5)...

I'm having hard time finding the center of inversion of cubic diamond structure. At first I thought (2,2,2) would be the center of inversion, but (1,1,3), (3,3,3), (1,3,1), (3,1,1) (i.e. four atoms inside the cube) are not centrosymmetric about (2,2,2).

I'm confused about the mathematics that led to the equation 4.5.9. Specifically, I'm confused about what the variables that describe U are. From the equation I think temperature T(through beta), chemical potential (through alpha), V (through E_s) and N (through... restriction on the...