相关论文: Vibrational Branching Ratios for Laser-Cooling of …

The vibrational branching ratios of SrOH for radiative decay to the ground electronic state, $X^{2}\Sigma^{+}$, from the first two electronically excited states, $A^{2}\Pi$ and $B^{2}\Sigma^{+}$, are determined experimentally at the…

We report a generally applicable computational and experimental approach to determine vibronic branching ratios in linear polyatomic molecules to the $10^{-5}$ level, including for nominally symmetry forbidden transitions. These methods are…

We excite YbF molecules to low-lying vibrational levels of the $A^2\Pi_{1/2}$ state, and of the nearby perturber state sometimes called [18.6]0.5. By dispersing the fluorescence, we measure branching ratios for the radiative decay to…

The simple structure of the BH molecule makes it an excellent candidate for direct laser cooling. We measure the branching ratios for the decay of the ${\rm A}^{1}\Pi (v'=0)$ state to vibrational levels of the ground state, ${\rm…

Alkaline earth monoalkoxide free radicals (MORs) have molecular properties conducive to direct laser cooling to sub-millikelvin temperatures. Using dispersed laser induced fluorescence (DLIF) measurements from a pulsed supersonic molecular…

A study of the intensity-borrowing mechanisms important to optical cycling transitions in laser-coolable polyatomic molecules arising from non-adiabatic coupling, contributions beyond the Franck-Condon approximation, and Fermi resonances is…

Ultracold CH radicals promise a fruitful testbed for probing quantum-state controllable organic chemistry. In this work, we calculate CH vibrational branching ratios (VBRs) and rotational branching ratios (RBRs) with ground state mixing. We…

Vibrational branching ratios in the B$^2\Sigma^+$ -- X$^2\Sigma^+$ and A$^2\Pi$ -- X$^2\Sigma^+$ optical-cycling transitions of BaH molecules are investigated using measurements and {\it ab initio} calculations. The experimental values are…

Laser cooling of large, complex molecules is a long-standing goal, instrumental for enabling new quantum technology and precision measurements. A primary consideration for the feasibility of laser cooling, which determines the efficiency…

Molecular laser cooling and trapping requires addressing all spontaneous decays to excited vibrational states that occur at the $\gtrsim 10^{-4} - 10^{-5}$ level, which is accomplished by driving repumping transitions out of these states.…

Molecular ions can be held in a chain of laser-cooled atomic ions by sympathetic cooling. This system is ideal for performing high-precision molecular spectroscopy with applications in astrochemistry and fundamental physics. Here we show…

Laser cycling of resonances can remove entropy from a system via spontaneously emitted photons, with electronic resonances providing the fastest cooling timescales because of their rapid relaxation rates. Although atoms are routinely laser…

Some of us have recently reported in Science 321 232 (2008) vibrational cooling of translationally cold Cs_2 molecules into the lowest vibrational level v=0 of the singlet X 1Sigma_g ground electronic state. Starting from a sample of cold…

Cooling the rotation and the vibration of molecules by broadband light sources was possible for trapped molecular ions or ultracold molecules. Because of a low power spectral density, the cooling timescale has never fell below than a few…

We perform magnetically-assisted Sisyphus laser cooling of the triatomic free radical strontium monohydroxide (SrOH). This is achieved with principal optical cycling in the rotationally closed $P\left(N"=1\right)$ branch of either the…

We report the measurement of the 1$^{1}\Sigma\longrightarrow$ 2$^{1}\Sigma$ transition of CaH$^+$ by resonance-enhanced photodissociation of CaH$^+$ that is co-trapped with laser-cooled Ca$^+$ . We observe four resonances that we assign to…

A prerequisite for laser cooling a molecular anion, which has not been achieved so far, is the precise knowledge of the relevant transition frequencies in the cooling scheme. To determine these frequencies we present a versatile method that…

Precision measurements with ultracold molecules require development of robust and sensitive techniques to produce and interrogate the molecules. With this goal, we theoretically analyze factors that affect frequency measurements between…

The transfer of weakly bound KRb molecules from levels just below the dissociation threshold into the vibrational ground state with shaped laser pulses is studied. Optimal control theory is employed to calculate the pulses. The complexity…

We have taken K-band spectra covering 7 cooling flow clusters. The spectra show many of the 1-0S transitions of molecular Hydrogen, as well as some of the higher vibrational transitions, and some lines of ionized Hydrogen. The line ratios…