一种微型化制造的双腔结构芯片原子钟87Rb蒸汽腔

碱金属蒸汽腔是芯片原子钟（CSACs）中重要的核心部件之一，其微型化制造具有重要的实用价值，同时也非常具有挑战性。采用MEMS 技术批量化制作了具有双腔结构的芯片原子钟87Rb 蒸汽腔阵列。在阳极键合过程中，通过原位化学反应产生纯净的87Rb 元素蒸汽，缓冲气体（N2）采用反充的方法充入到87Rb 蒸汽腔内以保证缓冲气体的压强可以精确的控制。所设计的双腔结构可以防止原位化学反应中产生的杂质阻挡光路，从而能够提高探测到的光信号的强度。通过原子钟桌面系统测试，得到了87Rb 元素D1 线的光学吸收谱和用于芯片原子钟锁频的误差信号，在90℃时，87Rb 元素D1 线纠偏信号的线宽（波峰与波谷间距）可达到0.53 kHz。测试结果表明，双腔结构的87Rb 蒸汽腔满足芯片原子钟或其他芯片级原子器件的设计要求。

A microfabricated 87Rb vapor cell with dual-chamber for chipscale atomic clock

Alkali vapor cell is one of the key components of chip-scale atomic clocks (CSACs), and its microfabrication is very significant yet challenging. Arrays of 87Rb vapor cell with dual-chamber for CSACs were batch fabricated by MEMS technology. Pure 87Rb vapor was produced by in-situ chemical reaction during anodic bonding process and buffer gas (N2) was backfilled to ensure the pressure is precisely controlled. The dual-chamber structure helps to prevent the impurity after reaction from blocking light path, in order to improve the intensity of optical signal. Optical absorption spectrum of 87Rb D1 line and the error signal used to lock the frequency of chip-scale atomic clock were finally obtained through experimental test. The peak-to-valley separation of the 87Rb D1 line error signal can reach 0.53 kHz at 90℃, which indicates that the 87Rb vapor cell can meet the requirement of CSACs or other chip-scale atomic devices (CSADs).