Progress in the miniature trapped ion optical clock development with 16 cc sealed trap tube

Optical clocks have well surpassed the frequency stability performance of microwave clocks. They have been mainly limited to tabletop setups and large rack-mount systems. Miniaturizing optical clocks will make the new technology and capability more ubiquitously applied to applications from navigation to fundamental science. Here we aim to develop a miniature space optical clock (mSOC) with the size of a compact microwave clock and capable of achieving a short-term stability of 10􀀀14 􀀀1=2 and noise oor of 10􀀀16. In this paper, we will describe the mSOC concept, discuss the experimental setup, and present recent results. We have demonstrated trapping single ions and characterized the ion lifetime in a 16-cc trap tube. The trap tube is completely sealed o  without any active pump. We also constructed a clock laser referenced to a small ultra-low expansion (ULE) reference cavity at a low 10􀀀14 level and observed the clock transition.