Progress report on development of ultrastable lasers for 27Al+ optical clock

The recent progress of ultra-stable lasers used for ²⁷Al⁺ optical frequency standards is presented. Two diode lasers are phase stabilized to ultra-stable ULE cavities, which will be frequency quadrupled to UV as the 267.4 nm ²⁷Al⁺ clock laser with sub-Hz level linewidth and the 267.0 nm shelving laser with 100 Hz level linewidth for fast detection respectively. In this report, less than 3 Hz linewidth of IR lasers at 1068 nm are achieved via Pound-Drever-Hall (PDH) stabilization for the 100 Hz shelving laser application. Dynamic analysis of cavity sensitivity to vibration is also presented.