Giant subthreshold amplification in synchronously pumped optical parametric oscillators

Abstract

Synchronously pumped parametric oscillators have been shown to have subthreshold giant amplification of such a magnitude that a macroscopic, entirely noise-driven, signal is present at output even when the device is below threshold. In this paper we quantify the magnitude of the amplification factor in terms of some key device parameters. We use non-normal operator theory to find the noise amplification factor (Kreiss constant) and show that the signal amplitude is proportional to it. We also determine that the noise sensitivity depends in a nontrivial way on the group velocity of the three fields

Quantum noise of a Bose-Einstein condensate in an optical cavity, correlations, and entanglement

“…Significant contributions to the photon and particle numbers were found, beyond that of the mean field. The strong depletion of the condensate shows some analogy with the excess noise in lasers [48,49], which was already discussed in our previous work [18]. It is interesting, however, that the huge nonclassical contribution in the autocorrelation of the photonic and atomic operators does not manifest in the entanglement of these variables.…”

The geometrical nature of optical resonances: from a sphere to fused dimer nanoparticles

“…Therefore, large surface fields in nanoparticles and large transient gain and excess noise in macroscopic unstable cavities and dissipative systems [10][11][12][13]h a v et h e same geometrical origin.…”

“…is defined as the Peterman factor [9] that gives the order of magnitude of transient gain and excess noise in unstable cavity modes. Therefore, large surface fields in nanoparticles and large transient gain and excess noise in macroscopic unstable cavities and dissipative systems [10][11][12][13] have the same geometrical origin.…”

Rapid Coherent Optical Modulation of Atomic Momenta via Pseudoresonances

“…Another consequence of non-normality is that the response to an external modulation can be very large even far from resonance, a phenomenon known as pseudoresonance [6,7]. In optics, transient growth has been predicted and observed in systems with non orthogonal modes where it affects the level of spontaneous emission noise [8][9][10] and in optical parametric oscillators [11,12]. A similar effect has been recently predicted in optical cavities filled with Bose-Einstein condensates [13], where excess noise can degrade the condensate and it underpins the response of nanoparticles to an incident field [14].…”