Secondary laser cooling and capturing of thulium atoms in traps

Secondary laser cooling has been realised on the weak dipole transition , , , , with the wavelength of and natural width of . The temperature of the atomic cloud in a magneto-optical trap (MOT) was at the lifetime of and the number of atoms . Approximately 1 % of atoms from the MOT have been reloaded to an optical dipole trap and to one-dimensional optical lattice at the wavelength of . The atom lifetime in the optical lattice was . We propose to employ thulium atoms captured in an optical lattice as an optical frequency reference.