@abdulmohamed9754 8 ай бұрын
Love the video! Im a phd student working on these topics with superconducting devices. we just measured 3dB vacuum squeezing, and has been a pain to wrap my head around the intuition of these experiments. Its really nice to see this in the optical domain and helps my understanding. Thanks for taking the time to make this video. Would love to see a video on transmission theory if you're able to do on
@rijoraju7133 7 ай бұрын
Hi there, I recently started working on BHD and squeezing. I have done the BHD for my laser and now I want to measure the vaccum noise of my laser source. Can you tell basic experimental procedure to measure vacuum noise of a laser source and which equipment is right to record it. As you state in your comment, if u have done the vacuum squeezing, I think you can help me with this one.
@shwifty123 8 ай бұрын
Epic speedrun! That was a one semester course (sort of) in 30 mins. Thanks!
@GeoffryGifari Жыл бұрын
sounds like homodyne detection of the quadrature of the vacuum state can be used (as one alternative) to measure the value of Planck's constant
@AndrewMacRae 10 ай бұрын
It would be interesting to try - you'd have to have a way to evaluate the photo-current in a way that wasn't referencing Planck's constant in the first place. Fun idea to work out!
@dibyendujana192 2 жыл бұрын
Can you please make two videos explaining coherence of light and squeezed state in a elaborative way .i can not get the intutive ideo from my advisor.i am doing a project theoretical quantum optics .please make a video to make my understanding clearer. Thank you sir.
@GeoffryGifari Жыл бұрын
oh a laser is considered a classical state? this is new to me since i often read about lasers in the context of their generation (population inversion and stimulated emission, treated with quantum mechanics) and their properties of "coherence" (related to quantum coherent state?)
@AndrewMacRae 10 ай бұрын
In the words of Peter Knight (paraphrasing George Orwell) "All states are quantum ... but some are more quantum than others."
@kamilcnar4551 2 жыл бұрын
The labels on the plot after 25:48 should be vise versa. Shouldn't the beating noise correspond to the squeezed light?
@AndrewMacRae 2 жыл бұрын
Oh shoot, you are correct! I'll make a note in the description. Thanks for pointing that out.
@arunsebastian4035 11 ай бұрын
Can I ask some doubts ?
@AndrewMacRae 10 ай бұрын
Of course!
@arunsebastian4035 8 ай бұрын
I am very very sorry for late reply, I started working on BHD and squeezing . But I am struggling with understand shot noise in an experimental context. I mean how to measure the quantum noise and how to differentiate a quantum, electronic, and laser noise experimentally. Can please tell me something about it. @@AndrewMacRae
@AndrewMacRae 7 ай бұрын
@@arunsebastian4035 No worries about the delay. Well there's a lot to say about this in general. In short the idea behind homodyne detection is that it accurately measures the "quantum noise" (meaning the expectation value of the quadrature of the field) if electronic noise is sufficiently low and the balancing is precise enough to subtract the classical laser noise. 1. Electronic Noise: This is what you measure when there is no light at all on the detector (i.e. no local oscillator). This is typically measured as a variance of a trace on a scope in the time domain, or on a spectrum analyzer to see the frequency domain picture. This should be much lower than the variance when a local oscillator is present. 2. Laser Noise: From this I take it to mean "classical" or "technical" noise. In fact even a perfect laser is noisy due to quantum noise - this is the "standard quantum limit". When looking in the frequency domain, the BHD with only the local oscillator present is supposed to be this value. This should be white noise - i.e. flat across all frequencies and additionally, should scale as the square root of the intensity. That is, if you 4x the optical power, this noise should double. 3. If 1 and 2 are taking care of, then what you are measuring is the quantum noise.
@bediha Жыл бұрын
"we assume things either spherical cows or simple harmonic oscillators " 😂yesss... everyhting in physics is simple harmonic oscillator
@TheBigBanggggg 7 ай бұрын
If you're an experimentalist, why don't you show us anything?
@jacobvandijk6525 6 ай бұрын
An experimentalist not able to show any experiment concerning the theory he is dealing with is like a religious preacherman.
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