The dispersed fluorescence following pulsed dye laser excitation of the $textrm{B}_2 Sigma^+ - textrm{X}^2 Sigma^+(0,0)$ band of a cold sample of SiO$^+$ has been recorded and analyzed. The branching ratios for $textrm{B}_2 Sigma^+ (v=0) rightarrow textrm{X}^2 Sigma^+(v)$ and $textrm{B}_2 Sigma^+ (v=0) rightarrow textrm{A}^2 Pi_i(v)$ emission were determined and compared with values predicted based upon existing experimental and theoretical data. The experimentally determined branching ratios show that the $textrm{B}_2 Sigma^+ (v=0) rightarrow textrm{X}^2 Sigma^+(v)$ transitions are somewhat less diagonal than predicted. The implications for laser cooling of a trapped sample of SiO$^+$ using broadband laser excitation are discussed.
We present measurements of the hyperfine coefficients and isotope shifts of the Dy I $683.731 $nm transition, using saturated absorption spectroscopy on an atomic beam. A King Plot is drawn resulting in an updated value for the specific mass shift $delta u_mathrm{684,sms}^mathrm{164-162}=-534 pm 17 MHz$. Using fluorescence spectroscopy we measure the excited state lifetime $tau_{684}=1.68(5) mu$s, yielding a linewidth of $gamma_mathrm{684} = 95 pm 3 kHz$. We give an upper limit to the branching ratio between the two decay channels from the excited state showing that this transition is useable for optical pumping into a dark state and demagnetization cooling.
The 1+1 REMPI spectrum of SiO in the 210-220 nm range is recorded. Observed bands are assigned to the $A-X$ vibrational bands $(v``=0-3, v`=5-10)$ and a tentative assignment is given to the 2-photon transition from $X$ to the n=12-13 $[X^{2}{Sigma}^{+},v^{+}=1]$ Rydberg states at 216-217 nm. We estimate the IP of SiO to be 11.59(1) eV. The SiO$^{+}$ cation has previously been identified as a molecular candidate amenable to laser control. Our work allows us to identify an efficient method for loading cold SiO$^{+}$ from an ablated sample of SiO into an ion trap via the $(5,0)$ $A-X$ band at 213.977 nm.
The Gamma Factory (GF) initiative aims at construction of a unique experimental tool exploiting resonant interaction of light with ultra-relativistic partially stripped ions (PSI) stored in circular accelerators at CERN. Resonant excitation of high-energy transitions of the ions is achieved through Doppler-boosting (by twice the Larmor factor; from hundred to several thousand times) of light energy. In order to efficiently excite the ions, and hence generate intense beams of scattered/fluorescent photons, a detailed knowledge of the ions energy structure and dynamics of optical pumping is required. Spectroscopic properties of PSI selected for the GF operation, as well as their optical pumping schemes are investigated. Two regimes of the light-ion interaction are identified, leading to different dynamics of the pumping process. The efficiency of the light-ion interaction as well as the number of photons emitted from a single ion bunch is estimated, both analytically and numerically, for three ions considered for the GF, i.e.~Li-like ${}^{208}_{phantom{0}82}$Pb$^{79+}$, Li-like ${}^{40}_{20}$Ca$^{17+}$, and H-like ${}^{208}_{phantom{0}82}$Pb$^{81+}$.
We use a magnetometer probe based on the Zeeman shift of the rubidium resonant optical transition to explore the atomic magnetic response for a wide range of field values. We record optical spectra for fields from few tesla up to 60 tesla, the limit of the coil producing the magnetic field. The atomic absorption is detected by the fluorescence emissions from a very small region with a submillimiter size. We investigate a wide range of magnetic interactions from the hyperfine Paschen-Back regime to the fine one, and the transitions between them. The magnetic field measurement is based on the rubidium absorption itself. The rubidium spectroscopic constants were previously measured with high precision, except the excited state Lande $g$-factor that we derive from the position of the absorption lines in the transition to the fine Paschen-Back regime. Our spectroscopic investigation, even if limited by the Doppler broadening of the absorption lines, measures the field with a 20 ppm uncertainty at the explored high magnetic fields. Its accuracy is limited to 75 ppm by the excited state Lande $g$-factor determination.
We report the detection of high-contrast and narrow Coherent Population Trapping (CPT) Ramsey fringes in a Cs vapor cell using a simple-architecture laser system. The latter allows the combination of push-pull optical pumping (PPOP) and a temporal Ramsey-like pulsed interrogation. An originality of the optics package is the use of a single Mach-Zehnder electro-optic modulator (MZ EOM) both for optical sidebands generation and light switch for pulsed interaction. Typical Ramsey fringes with a linewidth of 166 Hz and a contrast of 33 % are detected in a cm-scale buffer-gas filled Cs vapor cell. This technique could be interesting for the development of high-performance and low power consumption compact vapor cell clocks based on CPT.