A high-power spectral beamsplitter for closely spaced frequencies

Resolving closely spaced levels for Doppler mismatched double resonance

In this paper, we present experimental techniques to resolve the closely spaced hyperfine levels of a weak transition by eliminating the residual/partial two-photon Doppler broadening and cross-over resonances in a wavelength mismatched double resonance spectroscopy. The elimination of the partial Doppler broadening is based on velocity induced population oscillation (VIPO) and velocity selective saturation (VSS) effect followed by the subtraction of the broad background of the two-photon spectrum. Since the VIPO and VSS effect are the phenomena for near zero velocity group atoms, the subtract…

Level sequence and splitting identification of closely-spaced energy levels by angle-resolved analysis of the fluorescence light

The angular distribution and linear polarization of the fluorescence light following the resonant photoexcitation is investigated within the framework of the density matrix and second-order perturbation theory. Emphasis has been placed on "signatures" for determining the level sequence and splitting of intermediate (partially) overlapping resonances, if analyzed as a function of the photon energy of the incident light. Detailed computations within the multiconfiguration Dirac-Fock method have been performed especially for the $1s^{2}2s^{2}2p^{6}3s\;\, J_{i}=1/2 \,+\, γ_{1} \:\rightarrow\: (1s^…

Effect of Closely-Spaced Excited States on Electromagnetically Induced Transparency

Electromagnetically induced transparency (EIT) is a well-known phenomenon due in part to its applicability to quantum devices such as quantum memories and quantum gates. EIT is commonly modeled with a three-level lambda system due to the simplicity of the calculations. However, this simplified model does not capture all the physics of EIT experiments with real atoms. We present a theoretical study of the effect of two closely-spaced excited states on EIT and off-resonance Raman transitions. We find that the coherent interaction of the fields with two excited states whose separation is smaller …

通过Walsh调制动力学解耦光谱实现两个紧密间隔电磁场的超分辨

Super-resolution of two Closely-spaced Electromagnetic Fields via Walsh-Modulated Dynamical Decoupling Spectroscopy

提出基于Walsh调制动力学解耦（WMDD）序列的超分辨光谱协议，利用相位信息抑制散粒噪声，在1 ms测量时间内分辨间隔5 Hz的电磁场，突破传统频率分辨极限并大幅提升数据采集速度。