An ultrastable silicon cavity in a continuously operating closed-cycle cryostat at 4 K

W. Zhang, J. M. Robinson, L. Sonderhouse +8

We report on a laser locked to a silicon cavity operating continuously at 4 K with $1\times 10^{-16}$ instability and a median linewidth of 17 mHz at 1542 nm. This is a ten-fold i…