Recent content by Daz

Hi Pattarasak, If you do a google search for the Hong Ou Mandel experiment you will find many explanations of the way to construct a unitary matrix representation of the beam splitter in quantum optics.

Homework Statement It takes George 45 minutes to install a bollard in the street but it only takes Alex 30 minutes to do the same task. They work together as a team. If George and Alex install 7 bollards in 2 1/2 hours how are they going to get home? Homework Equations R = G-W Where R is...

8/15 I was surprised by a few that I got wrong.

No, it is not solely because of one thing (acceleration / deceleration of electrons, etc.) and you will not get a “continuous distribution of radiation” from a cold gas. As you correctly observed earlier there are a variety of mechanisms contributing to the observed spectra, whether that be...

I suppose that I should have pointed out that it is possible to get very, very close to the ideal black body curve and in fact it gets easier as the object gets hotter. That is for several reasons: (1) the “things” with which the light interacts (electrons, vibrational modes, etc) will follow...

Hi, I don’t think you will find an ABC model for GaAs devices. As I understand it (and I’m way rusty on this) the ABC model is an empirical model to describe the performance droop in nitride-based devices. As far as I’m aware GaAs devices don’t exhibit a performance droop and if they do it would...

I think there’s a misapprehension here that gases emit black body radiation. They do not. I suspect that the OP’s misapprehension that they do stems from lax terminology; some people write “black body radiation” when what they should really have written is “thermal radiation.” In fact, nothing...

Also, I'd like a reference for this bit, as that contradicts what I always thought.

Yes, I’ve noticed that CMOS sensors don’t saturate in the same way as CCDs where you tend to get vertical white streaks in the image as the charge overspills along the read-out line. But I guess they do something similar, nonetheless. This is one of the reasons why mega-pixel cameras require...

I too have seen this occur. It happens with CCD detectors where each pixel is essentially a potential well with a finite density of states. If the incident light intensity is high, the individual colour pixels saturate and charge starts spilling over into adjacent pixels. It’s called white-out...

This is a very current research area. Try a google search for "optical rectenna" - there are numerous articles available on-line describing things similar to what you are trying to achieve.

Single-crystal silicon. This particular piece is a ten-nines wafer or 99.99999999% pure :

As an interesting aside, that article about fire from the moon isn’t technically accurate, because the radiation we receive from the moon isn’t completely thermal. If it were, it too would have a Lambertian distribution and the moon would look like a Lambertian sphere. It would look like this...

What this boils down to is the fact that both black bodies are extended sources and radiate with a Lambertian distribution. What that article calls conservation of étendue is what most of us call the Lagrange invariant. Very crudely, it says that in a first-order optical system the product of...

Phys Rev Lett. Are tweeting snippets of the paper "until their servers are back online." (Obviously overloaded by us lot trying to get a peek!) https://twitter.com/PhysRevLett