M1L5d_CQ4.txt

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We really need prominently to discuss
quantum noise and short noise, the coherent state.
So just to make sure that we relate--
I will relate later everything to photon number,
because photon numbers intuitive.
You can count.
You can feel the photons, fluctuations of square root.
They immediately tell you Poisson, if it's less
than Poisson, all that.
So I want to make sure we are quickly associating photon
number with coherent states.
So therefore, the first question is,
if you have a coherent state alpha
and you take all the photons with a photodiode
of 100% efficiency, is the number