Recent content by nandan

If what I say above is correct, then another experiment can be imagined. Two photons generated by SPDC with broad spectral power density are made to fall on two input ports of a beam splitter with a delay between them which is much greater than the temporal coherence of two photons. Therefore...

Thanks a lot Marc for your detailed reply. I understand your point that individually the two photons have low coherence both spatially and temporally but due to entanglement of two photons, if you post-select one photon in a narrow momentum or spectral state, then the other photon will have high...

What is the coherence time for a pair of entangled photons produced in a nonlinear crystal? Is it related to coherence time of the pump photon? Also, if we say that the coherence time of the two photons is T, then does it mean that the two photons can interfere with each other even if their...

In fact there are some papers using multi-wavelength sources e.g. PHYSICAL REVIEW A 88, 053842 talks about one such setup. I believe that in this paper authors should have carefully explained what kind of detectors are being used e.g. eqn. 2 suggests that slow detectors are used even though this...

Yes. That is exactly what I am saying. For computational part in computational ghost imaging to work, the randomly varying phases of the source lasers have to be averaged over. In this regard, it is completely different from conventional ghost imaging. And I am surprised that not enough has been...

But in that case the intensity profile recorded in each image will be different due to the time dependent phase differences of the N different components of the source lasers. Such a fluctuating intensity pattern (due to phase fluctuations of lasers) cannot be calculated from just the phase...

That is precisely my point. The temporal resolution of the detector is important. It makes a difference to the final result as well. In conventional ghost imaging, the temporal resolution of detector can be chosen to be faster or slower than the coherence time of source laser(s). However, in...

I understand your point. But what I am trying to convey is that the physics involved in conventional and computational ghost imaging is different (at least in my opinion). And that this difference can lead to different results as I have tried to explain using two component source. And if the...

You are right when you say that an absolute additional phase will not make any difference to say a double slit interference pattern. But, if this additional phase is a time varying quantity, then it can make a difference. Since the fields from the two slits generally travel different distance to...

If the image is taken in time interval which is much smaller than the coherence time of the lasers (here the phase fluctuations of lasers are more important since the phase from SLM is held constant in one frame). If however, the image is acquired over a timescale longer than the coherence time...

If in computational ghost imaging, the correlation is calculated between average intensities (for each spatial phase realization of SLM) of bucket and scanning detectors (since the intensity data is acquired over the time for which each SLM phase profile is maintained to be constant), then the...

Thanks a lot @Cthugha for your replies. If I understand correctly, what you are saying is that the intensity correlations between bucket and scanning detectors are calculated between average intensities at these two detectors for each phase realization of SLM. If that is the case and the laser's...

But since the input laser beam also has some phase fluctuations, the total phase after passing through the SLM should also have similar phase fluctuations over and above the phase added by SLM. Will this phase fluctuation not affect the coherence time of resulting beam? Also, is there any...

In pseudo-thermal ghost imaging using a laser beam passing through a rotating ground glass plate, the temporal coherence is important since the intensities in both scanning and bucket detectors have to be measured within the coherence time of the beam. However, in computational ghost imaging...

light is a special case .no mater what speed of light cannot be more than what it is.its a relativity concept.