A physics package for rubidium atomic frequency standard with a short-term stability of 2.4 × 10−13 τ−1/2

Abstract

In this article, a new type of physics package with high signal to noise ratio for a rubidium atomic frequency standard is reported. To enhance the clock transition signal, a slotted tube microwave cavity with a field orientation factor of 0.93 and an absorption cell with the diameter of 30 mm were utilized in design of the cavity-cell assembly. Based on the spectral analysis of the three commonly used rubidium spectral lamps, the spectral lamp filled with Xe gas was chosen as the optical pumping source for its small line shape distortion. To suppress the shot noise of the signal, a band pass interference filter was used to filter out Xe spectral lines from the pumping light. A desk system of the rubidium frequency standard with the physics package was realized, and the short-term stability of the system was predicted and tested. The measured result is 2.4 × 10 τ up to 100 s averaging time, in good agreement with the predicted one.

Symmetric autobalanced Ramsey interrogation for high-performance coherent-population-trapping vapor-cell atomic clock

“…The pulsed optically pumped (POP) Rb frequency standard has demonstrated outstanding performances with a fractional frequency stability of 1.7 × 10 −13 τ −1/2 up to 1000 s and at the level of 10 −14 at 10 5 s 5 . Similar shortterm stabilities have been obtained with revisited doubleresonance schemes, pumped by lamp 6 or by laser 7 . An alternative approach is the development of atomic clocks based on coherent population trapping (CPT) 8,9 .…”

A high-performance Raman-Ramsey Cs vapor cell atomic clock

“…Numerous industrial applications including satellite-based navigation, telecommunication and space applications require field-deployable atomic clocks combining excellent fractional frequency stability, low power consumption and small size [1][2][3][4]. In this domain, lamp-based microwave Rb vapor cell atomic clocks based on optical-microwave double resonance technique, have been widely used for decades.…”

Characteristics of the space-borne rubidium atomic clocks for the BeiDou III navigation satellite system

“…北斗三号星载铷原子钟设计做了两项改进. 径微波腔也实现了初步应用 [8,15] . 图 7 散弹噪声、交调噪声和物理环境效应对甚高精度铷 原子钟频率稳定度的影响 铷原子钟系统, 短稳达到优于2.5×10 −13 /τ 1/2 水平 [8,15] .…”