Chinese Optics Letters, 2019, 17 (10): 100201, Published Online: Aug. 29, 2019
Micro-fabrication and hermeticity measurement of alkali-atom vapor cells based on anodic bonding Download: 1302次
020.1335 Atom optics 020.1670 Coherent optical effects 110.3960 Microlithography 300.6460 Spectroscopy, saturation
Abstract
A vapor cell provides a well-controlled and stable inner atmosphere for atomic sensors, such as atomic gyroscopes, atomic magnetometers, and atomic clocks, and its hermeticity affects the stability and aging of atomic sensors. We present the micro-fabrication of a micro-electromechanical system wafer-level hermit vapor cell based on deep reactive ion etching and vacuum anodic-bonding technology. The anodic-bonding process with the voltage increasing in steps of 200 V had a critical influence on vapor cell hermeticity. Further, the silicon–glass bonding surface was experimentally investigated by a scanning electron microscope, which illustrated that there were no visual cracks and defects in the bonding surface. The leak rate was measured using a helium leak detector. The result shows that the vapor cells with different optical cavity lengths comply with the MIL-STD-883E standard (5 × 10 8 mbar·L/s). Moreover, D2 absorption spectroscopy was characterized via optical absorption. The bonding strength was determined to be 13 MPa, which further verified the quality of the vapor cells.
Lu Zhang, Wendong Zhang, Shougang Zhang, Shubin Yan. Micro-fabrication and hermeticity measurement of alkali-atom vapor cells based on anodic bonding[J]. Chinese Optics Letters, 2019, 17(10): 100201.