Is there an uncertainty between amplitude and phase in an EM wave?

[fxdung]

Is there an uncertainty between amplitude and phase in classical quasi-monochromatic light?(E(t)=a(t)cos(phi(t)-omega_0*t))If it exist, what is the relation between classical and quantum uncertainty(delta I* delta phi>=1/2)?

 

[Dale]

Is there an uncertainty between amplitude and phase in classical quasi-monochromatic light?

Why would you think there are any classical uncertainty relationships at all?

 

[fxdung]

Because if we have a delta omega,then amplitude and phase are variant(the EM wave is not coherence any more?)

 

[DaveE]

I think you need to make a distinction between experimental measurement uncertainty and uncertainty in the definition of the waves involved. Theoretically waves, in the classical sense, each have a well defined frequency and phase. Of course in the real world, you may have more than one wave, or a non-linear system where the wave parameters change wrt time, or the inability to measure the difference.

 

[atyy]

https://books.google.com.sg/books?id=l-l0L8YInA0C&source=gbs_navlinks_s
Introduction to Quantum Optics: From the Semi-classical Approach to Quantized Light
Gilbert Grynberg, Alain Aspect, Claude Fabre
Section 5.3.6, p366: "In the limit of macroscopic fields, for small quantum fluctuations, phase and photon number look like complementary variables in the usual sense of quantum mechanics."

 

[vanhees71]

This refers to coherent states of large intensity and is well approximated by the classical limit of the em. field.

 

[PeterDonis]

"In the limit of macroscopic fields, for small quantum fluctuations, phase and photon number look like complementary variables in the usual sense of quantum mechanics."

Note that this refers to complementarity between phase and photon number, which is not the same as amplitude.