Laser Frequency Stabilization by Thin Atomic Vapor Cell

Y.-W. Chen, Chiyoe Yamanaka, Hideaki Niki +3 more

Sayaka Imanishi, U. Tanaka, Shinji Urabe

We report the frequency stabilization of a diode laser by applying the dichroic-atomic-vapor laser lock (DAVLL) method to a thin Rb vapor cell. A 1-mm-long Rb vapor cell is used to obtain a sub-Doppler spectrum that is required for frequency locking, which is easier than in the case of using a saturated absorption spectrometer. A 794-nm diode laser is tuned to the Rb D 1 line, and sub-Doppler signals are observed by introducing a pumping beam and a probe beam in a perpendicular direction. We obtain error signals by subtracting the signals of σ+ polarized beams from that of σ- polarized beams in the presence of a magnetic field and stabilized the 794 nm diode laser frequency without modulating laser parameters. The stability of the 794-nm diode laser is evaluated using other independently stabilized diode laser.

C. Affolderbach, C. Andreeva, S. Cartaleva +3 more

Kyoya Fukuda

In recent years, the coherent population trapping (CPT) phenomenon using a very small cell has attracted considerable attention for its potential application to ultra-compact atomic clock. For the miniaturization of CPT clock, it is important to clarify influence by the collision with atoms and cell walls. We study the effect of cell geometry on the CPT spectrum using a thin Cs vapor cell without buffer gas. When the cell length is below 1 mm and the laser intensity is sufficiently weak, the transit-time broadening is largely suppressed because only slow atoms have enough time to settle down on the dark state and contribute to the CPT signals. Furthermore, we show that introduction of buffer gas may broaden the CPT resonance in extremely thin cells. We also show that sub-Doppler signal which can be used for stabilization of laser frequency is obtained by using the CPT signal.

Kristen Oldja, Matthew J. Wright

Vladislav P. Gerginov, Vishal Shah, Svenja A. Knappe +2 more

We describe a novel technique for stabilizing frequency shifts in laser-interrogated vapor-cell atomic clocks. The method suppresses frequency shifts due to changes in the laser frequency, intensity, and modulation index as well as atomic vapor density. The clock operating parameters are monitored by using the atoms themselves, rather than by using conventional schemes for laser frequency and cell temperature control. The experiment is realized using a chip-scale atomic clock. The novel atomic-based stabilization approach results in a simpler setup and improved long-term performance.