Two-color continuous-variable quantum entanglement in a singly resonant optical parametric oscillator

Abstract

We apply the input-output theory of optical cavities to formulate a quantum treatment of a continuous-wave singly resonant optical parametric oscillator. This case is mainly relevant to highly nondegenerate signal and idler modes. We show that both intensity and quadrature squeezing are present and that the maximum noise reduction below the standard quantum limit is the same at the signal and idler frequencies as in the doubly resonant case. As the threshold of oscillation is approached, however, the intensity-difference and quadrature spectra display a progressive line narrowing which is absent in the balanced doubly resonant case. By use of the separability criterion for continuous variables, the signal-idler state is found to be entangled over wide ranges of the parameters. We show that attainable levels of squeezing and entanglement make singly resonant configurations ideal candidates for two-color quantum information processes, because of their ease of tuning in experimental realizations

Self-organization, pattern formation, cavity solitons, and rogue waves in singly resonant optical parametric oscillators

“…Equations ( 11) and ( 12), however, tell us that while the pump can be approximated to first order to a constant value A 0 , the idler has to grow along z from its initial value. This is in agreement with previous analysis below threshold where the important noise term is associated with the idler fluctuations at the entrance of the crystal [33]. In the case of SROPOs close to threshold, we can approximate E 0 and E 2 in ( 11) and ( 12) with…”

X-Ray Parametric Down-Conversion in the Langevin Regime

“…The Langevin method is a standard method to describe quantum systems that exhibit loss [11,12]. Several authors have considered the effect of cavity output coupling and included the effect of Langevin terms on PDC [13][14][15][16][17]. The Langevin method has also been used to describe the generation of paired photons by electromagnetically induced transparency [18][19][20][21][22].…”

Single-frequency optical parametric oscillator intracavity-pumped by a visible VECSEL for low-noise down-conversion to 1.55 µm

“…Therefore, the superior low intensity noise of the VECSEL, via combination of actively stabilizing the VECSEL fundamental frequency, as well as their ability to operate free of relaxation oscillations (class A dynamics), enables them to be highly promising pump sources for OPOs for targeting intensity-difference squeezed light. It is also important to note that the sub-shot-noise intensity correlations and squeezing levels of below-threshold SROs match those of DROs, yet with the advantage of a simpler experimental realization [40]. Further to the reduction in intensity noise, a significant reduction in quantum phase noise can be achieved by actively stabilizing the VECSEL fundamental frequency.…”