Quantum mechanical diffusion of the polarization of a laser

Excess Quantum Noise due to Nonorthogonal Polarization Modes

“…We have experimentally verified the polarization excess-noise factor predicted above. The setup was very similar to that used previously to determine quantumlimited linewidths [15,18]. A He-Xe gas laser was operated on line center of the 3.51-mm Xe transition, the capillary being filled with a He pressure of 1.2 kPa and a Xe pressure of a few Pa.…”

Excess Quantum Noise Due to Nonorthogonal Polarization Modes

“…The setup was very similar to that used previously to determine quantumlimited linewidths [15,18]. A He-Xe gas laser was operated on line center of the 3.51-mm Xe transition, the capillary being filled with a He pressure of 1.2 kPa and a Xe pressure of a few Pa.…”

“…We have measured the fundamental laser linewidth (determined from the width of the first harmonic in the spectra) as a function of the axial magnetic field [19]. For V ¿ A (orthogonal polarization eigenmodes, K pol 1) we recover the usual Schawlow-Townes linewidth [2,15,18]. By dividing all the measured linewidths by the asymptotic linewidth ͑V ¿ A͒ we find the polarization excess-noise factor, K pol .…”

“…jAj͒. The dynamics reduces then to the evolution of the angle of linear polarization u, which is governed by the Adler equation [15]:…”

“…The widths of the peaks in the spectra are proportional to the quantum-noise strength [6,7,15,18]. We have measured the fundamental laser linewidth (determined from the width of the first harmonic in the spectra) as a function of the axial magnetic field [19].…”