Development of Alkali Vapor Cell for Miniature Nuclear Magnetic Gyroscope

The article presents numerical requirements for vapor cells for a nuclear magnetic gyroscope. The design requirements for the cells, such as shape, size and transparency, as well as their influence on the characteristics of the gyroscope, in particular, on the angle random walk, are considered. The process of manufacturing vapor cells and control of their parameters is described.

EFFECT OF AMBIENT RELATIVE HUMIDITY AND SOAKING TIME ON THE FORMATION OF OCTADECYLTRICHLOROSILANE COATINGS ON BOROSILICATE GLASS SUBSTRATES FOR ALKALI-METAL VAPOR CELLS

The most sensitive spin-exchange relaxation-free (SERF) magnetometer generally requires a working temperature greater than 100∘C. To date, octadecyltrichlorosilane (OTS) coating is one of the best candidates for this temperature range. However, the performance and consistency of the OTS coatings within the alkali-metal vapor cells are still poor. In this paper, the formation of OTS coatings on borosilicate glass (BG) substrates was investigated. The effects of ambient relative humidity (RH) on the formation of OTS coatings were examined by atomic force microscopy (AFM) and contact angle measurement. The results showed that 75[Formula: see text] RH can improve the order of the OTS coatings and reduce the root mean square (RMS) roughness of the OTS coatings. Under three different ambient RHs, the soaking time of OTS molecules should be greater than 60[Formula: see text]min to form complete OTS coating.

Micro Vapor Cells Sealed by Two-step Bonding for Miniature Atomic Clocks

This paper reports the proposal, fabrication, and evaluation of Rb vapor cells sealed by two-step bonding for miniature atomic clocks. The proposed fabrication method is separating the light path filled with Alkali atoms and Alkali dispenser’s room at wafer level process. The first fabricated sample is unexpectedly sealed with some air, and the vapor cell is measured the absorption spectra and CPT resonance. The flow solving the problems is indicated, and the vapor cells are fabricated again with the improved process. The FWHM of CPT resonance fits almost the theoretical value in vacuum-sealed samples, which are filled with Rb atoms carried from one dispenser. These results show that fabricated vapor cells are filled with Rb without degassing or leaks, and the reliability of the fabrication process and the production efficiency can be expected. Rb vapor cell sealed in the controlled pressure with buffer gases N2/Ar is also fabricated and evaluated. The spectrum line is broadened, and CPT resonance peak is narrowed 4.0 kHz at 90 °C. These results show the proposal fabrication method of the alkali vapor cells is useful for miniature atomic clocks.