Recent content by Qiao

I we can only guess right? Since it's impossible/hard(maybe hawing radiation?) to get any information from a black hole.

@DrSteve Thank you for the suggestion. I didn't stop and think on what I was asking was actually quite personal and rude, my apologies.

So I've been thinking of continuing after my MSc degree to do a PhD. But I have trouble getting a good feel on research groups of quantum optics and nanophotonics in the world. So my situation is: I life in the Netherlands and I have a good feel on most research groups in the country, but I'm...

It is sort of a basic telescope setup. Except I don't expect go to get my function back when if I use a concave lens + convex lens.

I assume i is just √-1? Then: |a>< a|(|a>< a |) =|a>< a|a>< a | = |a>< a | |a>< a|( i| b><a |) = i|a>< a| b><a | = 0 i is just a number and numbers be moved to the front, back where ever you find convenient.

I always saw imaginary time the same way as the imaginary number, you always use it in your derivations up until the end where you just rotate back to real time where you so somehow get the physical answer you needed. Just like that you alway take the absolute value of a function to remove the...

"The Feynman Lectures on Physics Vol.1" by R. Feynman Chapter 15 (basic knowledge of calculus and algebra is sufficient) For more in depth on the Dirac equation "Modern Quantum Mechanics" by J.J. Sakurai chapter 8.2 (quite some knowledge of linear algebra and Einstein notation needed otherwise...

actually, I've thought about this some more with the following thought experiment. Take a concave lens, put an object on the left focal plane, next place a convex lens so that it's focus plane is at the virtual image plane of the concave lens. So now the second lens should in principle do...

Thanks. So then I would assume that if the object is at focus distance "f", the image plane with a perfect Fourier transform of the object will be at "f/2". I concluded this by drawing a quick ray diagram.

Hey, I was wondering, since for a convex lens the Fourier transform of a fields is in their real focus plane. Is it for a concave lens that the Fourier transform of a field is in the virtual focus plane? I can't find any book or paper that talks about how concave lenses work in terms of...

Thanks, I'll try that. I've also managed to get oscillation using a cylindric lens, but only in the axis where the beam is unfocused. But the intensity profile is still very ugly with higher order interference patterns.

The SLM is placed in the front focus plane of the first lens then there is a second lens afterwards with a shorter focal distance w.r.t. the first lens. Then a camera is placed at the end such that the camera is in both the back focal planes of both lenses. So to answer the question, it's placed...

Hi, I'm working with a Digital Micro-mirror Device type SLM and my goal is to convert my laser from a gaussian to flat-head intensity profile. And then the tricky part is to make the beam oscillate up and down on the camera using just the SLM. Apparently I was to naive to think that moving my...

Hi, I'm Qiao a 25 year old experimental physics student. My main interests right now are ultra cold gasses(specifically Bose-Einstein condensates) and interaction between light and matter.