We propose a new method to cool the yb^3＋-doped ZBLANP glass in a standing-wave cavity. There are two advantages of this cavity-enhanced technique： the pumping power is greatly enhanced and the absorption of the cooling material is greatly increased. We introduce the basic principle of the cavity-enhanced laser cooling and discuss the cooling effect of a solid-state material in a cavity. From the theoretical study, it is found that the laser cooling effect is strongly dependent on the reflectivity of the cavity mirrors, the length of the solid material, the surface scattering of the material, and so on. Some optimal parameters for efficient laser cooling are obtained.
A graphically oriented interactive program for assignments of rotationally resolved molecular spectra has been devised. The program functions by grouping spectral lines in term of the second difference principle. and graphing spectral intensity versus frequency in a bar graph of the selected groups, distinguished by color and/or line-type. This allows for easy detection of regular patterns buried in the observed spectrum. Furthermore, it includes a Loomis-Wood view for assisting in spectral assignments. As an example, the program was applied in assigning the molecular spectrum of the production in the discharge of PCl3 buffered by helium gas, which may belong to several species. The results suggest that the program is highly efficient and quite useful in the assignment and the analysis of molecular spectra, especially those of symmetric top, slightly asymmetric top and linear molecules. The accuracy and efficiency of this program will likely ensure its wide application in the processing of molecular spectra.
We have calculated the Stark effect of CH3F molecules in external electrical fields, the rotational population of supersonic CH3F molecules in different quantum states, and analyse the motion of weak-field-seeking CH3F molecules in a st＇ate ｜J = 1, KM = -1） inside the electrical field of a Stark decelerator by using a simple analytical model. Threedimensional Monte Carlo simulation is performed to simulate the dynamical slowing process of molecules through the decelerator, and the results are compared with those obtained from the analytical model, including the phase stability, slowing efficiency as well as the translational temperature of the slowed molecular packet. Our study shows that with a modest dipole moment （-1.85 Debye） and a relatively slight molecular weight （-34.03）, CH3F molecules in a state ｜J= 1, KM = -1） are a good candidate for slowing with electrostatic field. With high voltages of ±10 kV applied on the decelerator, molecules of 370 m/s can be brought to a standstill within 200 slowing stages.
A novel scheme for guiding arbitrary buffer-gas cooled neutral molecules in a hollow optical fiber （HOF） using a red-detuned HEll mode is proposed and analysed theoretically. We give the electromagnetic field distribution of the HEll mode in the HOF and calculate the optical potential of an 12 molecule, and study the molecule guiding mechanism using a classical Monte Carlo simulation. Using a 6 kW input laser, an S-shape HOF with a 2 cm curvature radius for both bends, and an input molecular beam with a transverse temperature of 0.5 K and longitudinal temperature of 5 K, we obtain a guiding efficiency of -0.126% for the scheme, and the transverse and longitudinal temperatures of the guided molecular beam are 1.9 mK and 0.5 K, respectively.
