Transportable clock laser system with an instability of 1.6 x 10(-16)

We present a transportable ultra-stable clock laser sys-tem based on a Fabry-Perot cavity with crystalline Al0.92Ga0.08As/GaAs mirror coatings, fused silica (FS) mir-ror substrates, and a 20 cm-long ultra-low expansion (ULE) glass spacer with a predicted thermal noise floor of mod sigma(y) = 7 x 10(-17) in modified Allan deviation at one second averaging time. The cavity has a cylindrical shape and is mounted at 10 points. Its measured sensitivity of the fractional frequency to acceleration for the three Cartesian directions are 2(1) x 10(-12) /(ms(-2)), 3(3) x 10(-12) /(ms(-2)), and 3(1) x 10(-12) /(ms(-2)), which belong to the lowest acceleration sensitivities published for transportable systems. The laser system's instability reaches down to mod sigma(y) = 1.6 x 10(-16) (C) 2022 Optica Publishing Group