Note: Pulsed optically pumped atomic clock based on a paraffin-coated cell.

We report on the implementation of a pulsed optically pumped atomic clock based on a paraffin-coated cell. The relaxation times are measured, with the longitudinal relaxation time, T = 9.7 ± 0.

Frequency stability of a pulsed optically pumped atomic clock with narrow Ramsey linewidth.

In general, the linewidth of the Ramsey central fringe (RCF) is equal to 1/(2T), where T is the Ramsey free-evolution time. We demonstrate that the RCF linewidth of a pulsed optically pumped (POP) atomic clock with orthogonal polarization detection based on the magneto-optical rotation effect can be narrowed down to 1/(4T). The Allan deviation of the POP atomic clock decreases from 2.

Pulsed optically pumped atomic clock with zero-dead-time.

By alternatively operating two pulsed optically pumped (POP) atomic clocks, the dead time in a single clock can be eliminated, and the local oscillator can be discriminated continuously. A POP atomic clock with a zero-dead-time (ZDT) method is then insensitive to the microwave phase noise. From τ = 0.

Ultralow frequency Stokes and anti-Stokes Raman spectroscopy of single living cells and microparticles using a hot rubidium vapor filter.

We report on ultralow frequency Stokes and anti-Stokes Raman spectroscopy of single living cells and microsized particles in an aqueous medium with a frequency shift down to 10 cm(-1) by the combination of a hot rubidium (Rb) vapor filter, a confocal pinhole, and optical trapping. A single frequency-stabilized diode laser beam at 780.2 nm is used to optically trap and excite a single living cell or microparticle, and the Rayleigh scattering light from the particle is effectively blocked with a Rb vapor cell and a confocal pinhole.

High-contrast and narrow-linewidth resonant profile for continuous operation atomic clock.

We report a high-contrast and narrow-linewidth resonant line profile by measuring the magneto-optical rotation of the transmitted light in a forward-scattering arrangement. We also report the splitting of the transmitted line profile at a strong microwave excitation. This profile may provide a good competitive scheme for the passive Rb frequency standard.

Detection of ultrahigh resonance contrast in vapor-cell atomic clocks.

We propose and demonstrate a novel detection scheme of clock signals and obtain an ultrahigh resonance contrast up to 90%, which leads to the remarkable improvement of the precision of the signal-to-noise ratio. The frequency stability in terms of Allan deviation of the proposed detection scheme is improved by an order of magnitude under equivalent conditions.