Isolation of Axi-symmetrical Optical Resonator Modes

V. K. Ablekov, Vadim S. Belyaev, V. P. Vasil'ev +3 more

Aleksandr V. Karpenko, S. P. Vyatchanin

We develop a multimode quantum model of optical-axis misalignment in a simplified representation of the differential mode of an Advanced LIGO interferometer. The system is described as two coupled optical resonators corresponding to the signal extraction cavity and the arm cavity. Analytical expressions for the mode-mixing coefficients are derived, establishing a direct connection between geometrical perturbations of optical elements and multimode optical dynamics. Using the developed formalism, we investigate the influence of optical-axis misalignment on quantum-noise-limited sensitivity and injected squeezed states. We show that misalignment between the signal extraction cavity and the arm cavity leads to significant sensitivity degradation, frequency-dependent rotation of the squeezing ellipse, and a reduction of the observable squeezing in the fundamental spatial mode. At the same time, the injected squeezing is not destroyed but redistributed among coupled spatial modes. The resulting mode coupling generates quantum correlations between the fundamental and higher-order modes and leads to spatial-mode entanglement verified using the positive partial transpose criterion. Our results demonstrate that optical-axis misalignment should be treated as a coherent multimode quantum process rather than as a simple optical loss mechanism.

Stephen Lynch

O. N. Gadomskiĭ, Yu. V. Abramov

A nanostructural object consisting of two atoms is proven to contain two or four dimensional resonances depending on whether these atoms are identical or different. Each of the atoms is characterized by linear isotropic polarizability and contains one isolated resonance. The frequency of the dimensional resonances considerably differs from the resonance frequencies of the isolated atoms, and the effective resonance polarizabilities of the atoms in the nanostructure approximately coincide with the resonance values of polarizabilities of the isolated atoms. It is shown that, in the nanostructure consisting of two different atoms, two of four resonances have a negative dispersion. It is also shown that the nanostructural object has an induced anisotropy in the case of a fixed position of the object axis relative to the direction of incidence of the external wave.

Vincent Ginis, Ileana-Cristina Benea-Chelmus, Jinsheng Lu +2 more

Optical resonators are optical components with numerous applications in modern physics and technology [1]. Indeed, they can provide spectral selectivity of optical signals and increase the intensity of light in a small volume of space. For these reasons, among others, they are important components in devices such as lasers. Resonators can also be used for frequency doubling, sum and difference frequency generation, optical parametric amplification and optical isolation. They have a wide range of applications, including chemical, biological and thermal spectroscopy and optical communication networks. In addition, resonators provide an ideal platform for studying and controlling quantum mechanical interactions.

Robert John Collins, Joseph A. Giordmaine