Bragg-induced orbital angular-momentum mixing in paraxial high-finesse cavities

Nonparaxial electromagnetic Bragg scattering in periodic media with PT symmetry

The evolution of a pair of resonant Bragg modes through a medium characterized by a complex one-dimensional $\mathcal{PT}$-symmetric periodic permittivity is thoroughly investigated. Analytic solutions of Maxwell's equations are derived beyond the paraxial approximation to investigate the periodic energy exchange that occurs between the Bragg modes for the Hermitian lattices as well as for complex lattices. Three regimes defined by the symmetry breaking point are discussed: below it, above it and at it. These regimes are determined by the existence of four real eigenvalues in the symmetric pha…

Ultra-low-loss nanofiber Fabry-Pérot cavities optimized for cavity quantum electrodynamics

We demonstrate the fabrication of ultra-low-loss, all-fiber Fabry-Pérot cavities containing a nanofiber section, optimized for cavity quantum electrodynamics. By continuously monitoring the finesse and fiber radius during fabrication of a nanofiber between two fiber Bragg gratings, we are able to precisely evaluate taper transmission as a function of radius. The resulting cavities have an internal round-trip loss of only 0.31% at a nanofiber waist radius of 207 nm, with a total finesse of 1380, and a maximum expected internal cooperativity of $\sim$ 1050 for a cesium atom on the nanofiber surf…

高应力Si3N4反射膜与腔体布拉格镜单片集成

High-Stress Si3N4 Reflective Membranes Monolithically Integrated with Cavity Bragg Mirrors

本研究提出了一种高应力Si3N4反射膜与腔体布拉格镜单片集成方法，实现了高Q因子的光力学器件，适用于精密传感和量子光子学。

High-finesse Fabry-Perot cavities with bidimensional Si$_3$N$_4$ photonic-crystal slabs

Light scattering by a two-dimensional photonic crystal slab (PCS) can result in dramatic interference effects associated with Fano resonances. Such devices offer appealing alternatives to distributed Bragg reflectors or filters for various applications such as optical wavelength and polarization filters, reflectors, semiconductor lasers, photodetectors, bio-sensors, or non-linear optical components. Suspended PCSs also find natural applications in the field of optomechanics, where the mechanical modes of a suspended slab interact via radiation pressure with the optical field of a high finesse …

Aberrated optical cavities

Optical cavities are an enabling technology of modern quantum science: from their essential role in the operation of lasers, to applications as fly-wheels in atomic clocks and interaction-enhancing components in quantum optics experiments, developing a quantitative understanding of the mode-shapes and energies of optical cavities has been crucial for the growth of the field. Nonetheless, the standard treatment using paraxial, quadratic optics fails to capture the influence of optical aberrations present in modern cavities with high finesse, small waist, and/or many degenerate modes. In this wo…

Tunable open-access microcavities for on-chip cQED

We report on the development of on-chip microcavities and show their potential as a platform for cavity quantum electrodynamics experiments. Microcavity arrays were formed by the controlled buckling of SiO2/Ta2O5 Bragg mirrors, and exhibit a reflectance-limited finesse of 3500 and mode volumes as small as 35lambda^3. We show that the cavity resonance can be thermally tuned into alignment with the D2 transition of 87Rb, and outline two methods for providing atom access to the cavity. Owing to their small mode volume and high finesse, these cavities exhibit single-atom cooperativities as high as…

非线性铌酸锂微腔中的超快光学门控

Ultrafast optical gating in a nonlinear lithium niobate microcavity

在高精细度非线性铌酸锂微腔中利用飞秒脉冲实现超快腔内光学门控，通过和频与差频生成实现腔内状态的按需读出与飞秒级控制，为量子态存储与光物质相互作用实时操控铺路。

Frequency splitting of polarization eigenmodes in microscopic Fabry-Perot cavities

We study the frequency splitting of the polarization eigenmodes of the fundamental transverse mode in CO2 laser-machined, high-finesse optical Fabry-Perot cavities and investigate the influence of the geometry of the cavity mirrors. Their highly reflective surfaces are typically not rotationally symmetric but have slightly different radii of curvature along two principal axes. We observe that the eccentricity of such elliptical mirrors lifts the degeneracy of the polarization eigenmodes. The impact of the eccentricity increases for smaller radii of curvature. A model derived from corrections t…

Optics of spin-noise-induced gyrotropy of asymmetric microcavity

The optical gyrotropy noise of a high-finesse semiconductor Bragg microcavity with an embedded quantum well (QW) is studied at different detunings of the photon mode and the QW exciton resonances. A strong suppression of the noise magnitude for the photon mode frequencies lying above exciton resonances is found. We show that such a critical behavior of the observed optical noise power is specific of asymmetric Fabry-Perot resonators. As follows from our analysis, at a certain level of intracavity loss, the reflectivity of the asymmetric resonator vanishes, while the polarimetric sensitivity to…