What Does 0.1 Expected Photon Per Pulse Mean in Quantum Cryptography?

[phonon44145]

Maybe a stupid question, but anyway. The paper "Experimental Quantum Cryptography" by C. Bennettet al. discusses laser pulses of 0.1 expected photon per pulse. What does that mean physically? Is it that 90% of laser pulses are not pulses at all, containing no photons and thereby no energy? Or are these pulses real in the same sense as wave function is real and the photon wave function can collapse into anyone of the pulses? Or is it that each pulse is a Schrödinger Cat superposition between emitted and non-emitted photon? If it can be of any help, another paper on the same topic (S. N. Molotkov, "Integration of Quantum Cryptography into fiber-optic telecommunication systems") claims that laser radiation(coherent state) has Poisson statistics in the photon number. Thanks in advance.

 

[Julian Blair]

I don't think that this is a stupid question! because I have a similar question involving Rabi oscillations of state probabilities induced by photons or parts of photons. Since this tread is do old, I'll post my question as a new thread.