Optical parametric oscillators (OPOs) are known to induce non-classical spatial correlations in the transverse profile of emitted light beams. We show how intracavity photonic crystals modify their stability as well as quantum fluctuations improving squeezed states.
The effects of an intracavity photonic crystal in a multimode optical parametric oscillator are studied, with a special focus on quantum fluctuations. The capability to either stimulate or inhibit the spatial instability, lowering or increasing the parametric threshold, allows to control the intensity fluctuations and correlations. A significative quantum noise reduction and an increase of the range of squeezed quadratures are found above threshold where spatial Einstein-Podolsky-Rosen entanglement and inseparability are found.
We show how to control spatial quantum correlations in a multimode, degenerate, type-I optical parametric oscillator below threshold by introducing a spatially inhomogeneous medium, such as a photonic crystal, in the plane perpendicular to light propagation. We obtain the analytical expressions for all of the correlations in terms of the relevant parameters of the problem and study the number of photons, entanglement, squeezing, and twin beams. Considering different regimes and configurations, we show that it is possible to tune the instability thresholds as well as the quantumness of correlations by breaking the translational invariance of the system through a photonic-crystal modulation.
We show how to tune quantum noise in nonlinear systems by means of periodic spatial modulation. We prove that the introduction of an intracavity photonic crystal in a multimode optical parametric oscillator inhibits and enhances light quantum fluctuations. Furthermore, it leads to a significant noise reduction in field quadratures, robustness of squeezing in a wider angular range, and spatial entanglement. These results have potential benefits for quantum imaging, metrology, and quantum information applications and suggest a control mechanism of fluctuations by spatial modulation of interest also in other nonlinear systems.
Optical parametric oscillators (OPO) have been extensively used in the continuous variable quantum optics community as a resource to produce non-classical states of light, including squeezed states or entangled beams. In this paper, general description of multimode OPOs is presented, show that they are able to produce a very wide variety of multimode quantum states of light, and give techniques to measure or separate them. The description applies equally to the spatial and temporal configurations, which are experimentally studied in lab.
The Optical Parametric Oscillator (OPO) has been one of the most versatile source of non-classical states of light.Usual configurations of such devices are a macroscopic second order nonlinear crystals inside an optical cavity.Recently the use of silicon photonics techniques allowed the implementation of high quality factor microcavities and OPOs which include several technological advantages over usual configuration as a small size, bigger bandwidth, CMOS compatibility, facility to engineer the dispersion properties and compatibility with commercial optical fiber communications.Nevertheless Contents vii 4.3.2.2 Three Modes Correlations . . . . . . . . . . . . . . . . . .4.3.2.