Related papers: Progress on indium and barium single ion optical f…

We demonstrate precision measurement and control of inhomogeneous broadening in a multi-ion clock consisting of three $^{176}$Lu$^+$ ions. Microwave spectroscopy between hyperfine states in the $^3D_1$ level is used to characterise…

We present a method that uses radio-frequency pulses to cancel the quadrupole shift in optical clock transitions. Quadrupole shifts are an inherent inhomogeneous broadening mechanism in trapped ion crystals, limiting current optical ion…

In recent years, multiple Light Detection and Ranging (LiDAR) systems have grown in popularity due to their enhanced accuracy and stability from the increased field of view (FOV). However, integrating multiple LiDARs can be challenging,…

Today's most accurate clocks are based on laser spectroscopy of electronic transitions in single trapped ions and feature fractional frequency uncertainties below $1\times10^{-18}$. Scaling these systems to multiple, simultaneously…

Numerous few-electron atomic systems are considered which can be used effectively for observing a potential variation of the fine-structure constant $\alpha$ and the electron-proton mass ratio $m_e/m_p$. We examine optical magnetic dipole…

Advances in accelerator technology have led to significant improvements in the quality of muon beams over the past decades. Investigations of the muon and muonium enable precise measurements of fundamental constants, as well as searches for…

We report the first driving of the $7s\ ^2S_{1/2}\rightarrow 6d\ ^2D_{3/2}$ and $7s\ ^2S_{1/2}\rightarrow 6d\ ^2D_{5/2}$ electric quadrupole (E2) transitions in Ra$^{+}$. We measure the frequencies of both E2 transitions, and two other…

We perform high-resolution real-time read-out of the motion of a single trapped and laser-cooled Ba ion. By using an interferometric setup we demonstrate shot-noise limited measurement of thermal oscillations with resolution of 4 times the…

We report absolute optical frequencies of electronic transitions from the $X\, ^2\Pi_{3/2},v''=0,J''=3/2$ rovibronic ground state to the 12 lowest levels of the $A\, ^2\Sigma^+,v'=0$ vibronic state in $^{16}$OH, as well as to the 16 lowest…

The optical properties of the superconducting single crystal Rb$_{0.8}$Fe$_{1.68}$Se$_2$ with $T_{c}$ $\simeq$ 31 K have been measured over a wide frequency range in the $ab$ plane. We found that the optical conductivity is dominated by a…

We report a comprehensive experimental study of spontaneous Brillouin scattering in a few-mode optical fiber, resolving both forward and backward scattering processes for intra- and inter-modal interactions. Using heterodyne detection,…

The systematic shifts of the transition frequencies in the molecular hydrogen ions are of relevance to ultra-high-resolution radio-frequency, microwave and optical spectroscopy of these systems, performed in ion traps. We develop the…

We present a novel method for engineering an optical clock transition that is robust against external field fluctuations and is able to overcome limits resulting from field inhomogeneities. The technique is based on the application of…

Recent experimental progress in cooling, trapping, and quantum logic spectroscopy of highly-charged ions (HCIs) made HCIs accessible for high resolution spectroscopy and precision fundamental studies. Based on these achievements, we explore…

The electric dipole-forbidden, quadrupole 6S1/2 <-> 5D3/2 transition in Ba+ near 2051 nm, with a natural linewidth of 13 mHz, is attractive for potential observation of parity non-conservation, and also as a clock transition for a barium…

We use a Fourier transform spectrometer based on a compact mid-infrared difference frequency generation comb source to perform broadband high-resolution measurements of nitrous oxide, $^{14}$N$_2$$^{16}$O, and retrieve line center…

The optical manipulation of Ba$^{+}$ ions is mainly performed by a 493 nm laser for the S$_{1/2}$-P$_{1/2}$ transition and a 650 nm laser for the P$_{1/2}$-D$_{3/2}$ transition. Since the branching ratio between the 493 nm and 650 nm…

We report the direct frequency measurement of the visible 5s$^2$ $^1$S$_0$-5s 5p$^3$P$_1$ intercombination line of strontium that is considered a possible candidate for a future optical frequency standard. The frequency of a…

We investigate the tuning behavior of a novel type of single-frequency optical synthesizers by phase comparison of the output signals of two identical devices. We achieve phase-stable and cycle slip free frequency tuning over 28.1 GHz with…

Observations at mas-resolution scales and high dynamic range hold a central place in achieving, for instance, the spectroscopic characterization of exo-Earths or the detailed mapping of their protoplanetary disc birthplace. Ground or…