Abstract

The enhancement of fluctuations near a critical point is a common feature of transition phenomena. However up to now most of the interest was concentrated towards the amplitude of the fluctuations but little attention was paid to the phase properties of the response signals. Following an experiment by Bocko and Battiato on a p-n junction diode (Phys. Rev. Lett. 60, 1763 (1988)), we have investigated phase sensitive noise deamplification near a period-doubling bifurcation in a laser. In fact the quadrature response of a driven nonlinear system, a CO₂ laser with an intracavity modulator in our experiment, presents reduced fluctuations while the in-phase component is amplified as expected for the signal itself.

© 1992 IQEC